changeset 8986:392bbcd8a88b

Database inserts accelerated by suppressing unnecessary database queries for new data series
author mschaefer
date Sun, 08 Apr 2018 18:07:06 +0200 (2018-04-08)
parents 27851cfda84a
children 5ff8ce9a2e06
files backend/src/main/java/org/dive4elements/river/importer/ImportBedHeight.java backend/src/main/java/org/dive4elements/river/importer/ImportBedHeightValue.java backend/src/main/java/org/dive4elements/river/importer/ImportCrossSection.java backend/src/main/java/org/dive4elements/river/importer/ImportCrossSectionLine.java backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModel.java backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModelValue.java backend/src/main/java/org/dive4elements/river/importer/ImportHYK.java backend/src/main/java/org/dive4elements/river/importer/ImportHYKEntry.java backend/src/main/java/org/dive4elements/river/importer/ImportHYKFlowZone.java backend/src/main/java/org/dive4elements/river/importer/ImportHYKFormation.java backend/src/main/java/org/dive4elements/river/importer/ImportPorosity.java backend/src/main/java/org/dive4elements/river/importer/ImportPorosityValue.java backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoad.java backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLS.java backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLSValue.java backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadValue.java backend/src/main/java/org/dive4elements/river/importer/ImportWst.java backend/src/main/java/org/dive4elements/river/importer/ImportWstColumn.java backend/src/main/java/org/dive4elements/river/importer/ImportWstColumnQRange.java
diffstat 19 files changed, 832 insertions(+), 723 deletions(-) [+]
line wrap: on
line diff
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportBedHeight.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportBedHeight.java	Sun Apr 08 18:07:06 2018 +0200
@@ -12,6 +12,7 @@
 import java.util.List;
 
 import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.BedHeight;
 import org.dive4elements.river.model.BedHeightType;
 import org.dive4elements.river.model.ElevationModel;
@@ -40,12 +41,15 @@
 
     protected List<ImportBedHeightValue> values;
 
+    protected StoreMode storeMode;
+
     protected BedHeight peer;
 
 
     public ImportBedHeight(final String description) {
         this.description = description;
         this.values      = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
 
@@ -178,9 +182,11 @@
                     (this.oldElevationModel != null) ? this.oldElevationModel.getPeer() : null, this.range.getPeer(river),
                             this.evaluationBy, this.description, this.sounding_width_info, this.comment);
             session.save(this.peer);
+            this.storeMode = StoreMode.INSERT;
         }
         else {
             this.peer = bedHeights.get(0);
+            this.storeMode = StoreMode.UPDATE;
         }
 
         return this.peer;
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportBedHeightValue.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportBedHeightValue.java	Sun Apr 08 18:07:06 2018 +0200
@@ -11,6 +11,7 @@
 import java.util.List;
 
 import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.BedHeight;
 import org.dive4elements.river.model.BedHeightValue;
 import org.hibernate.Query;
@@ -61,13 +62,18 @@
         if (this.peer != null)
             return this.peer;
 
+        List<BedHeightValue> values;
         final Session session = ImporterSession.getInstance().getDatabaseSession();
-        final Query query = session.createQuery("FROM BedHeightValue WHERE (bedHeight=:bedHeight)"
-                + " AND (station BETWEEN (:station-0.0001) AND (:station+0.0001))");
-        query.setParameter("bedHeight", bedHeight);
-        query.setParameter("station", this.station);
-        final List<BedHeightValue> values = query.list();
-        if (values.isEmpty()) {
+        if (this.bedHeight.storeMode == StoreMode.INSERT)
+            values = null;
+        else {
+            final Query query = session.createQuery("FROM BedHeightValue WHERE (bedHeight=:bedHeight)"
+                    + " AND (station BETWEEN (:station-0.0001) AND (:station+0.0001))");
+            query.setParameter("bedHeight", bedHeight);
+            query.setParameter("station", this.station);
+            values = query.list();
+        }
+        if ((values == null) || values.isEmpty()) {
             this.peer = new BedHeightValue(bedHeight, this.station, this.height, this.uncertainty, this.dataGap, this.soundingWidth,
                     this.minHeight, this.maxHeight);
             session.save(this.peer);
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportCrossSection.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportCrossSection.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,16 +8,15 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.River;
-import org.dive4elements.river.model.CrossSection;
-import org.dive4elements.river.model.TimeInterval;
-
-import org.hibernate.Session;
-import org.hibernate.Query;
-
 import java.util.List;
 
 import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.CrossSection;
+import org.dive4elements.river.model.River;
+import org.dive4elements.river.model.TimeInterval;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 /** CrossSection to be imported, holds list of ImportCrossSectionLines. */
 public class ImportCrossSection
@@ -28,6 +27,7 @@
     protected String                       description;
     protected ImportTimeInterval           timeInterval;
     protected List<ImportCrossSectionLine> lines;
+    protected StoreMode storeMode;
 
     protected CrossSection peer;
 
@@ -35,94 +35,97 @@
     }
 
     public ImportCrossSection(
-        ImportRiver                  river,
-        String                       description,
-        ImportTimeInterval           timeInterval,
-        List<ImportCrossSectionLine> lines
-    ) {
+            final ImportRiver                  river,
+            final String                       description,
+            final ImportTimeInterval           timeInterval,
+            final List<ImportCrossSectionLine> lines
+            ) {
         this.river        = river;
         this.description  = description;
         this.timeInterval = timeInterval;
         this.lines        = lines;
+        this.storeMode = StoreMode.NONE;
         wireWithLines();
     }
 
     public void wireWithLines() {
-        for (ImportCrossSectionLine line: lines) {
+        for (final ImportCrossSectionLine line: this.lines) {
             line.setCrossSection(this);
         }
     }
 
     public ImportRiver getRiver() {
-        return river;
+        return this.river;
     }
 
-    public void setRiver(ImportRiver river) {
+    public void setRiver(final ImportRiver river) {
         this.river = river;
     }
 
     public String getDescription() {
-        return description;
+        return this.description;
     }
 
-    public void setDescription(String description) {
+    public void setDescription(final String description) {
         this.description = description;
     }
 
     public ImportTimeInterval getTimeInterval() {
-        return timeInterval;
+        return this.timeInterval;
     }
 
-    public void setTimeInterval(ImportTimeInterval timeInterval) {
+    public void setTimeInterval(final ImportTimeInterval timeInterval) {
         this.timeInterval = timeInterval;
     }
 
     public void storeDependencies() {
 
-        log.info("store cross section '" + description + "'");
+        log.info("store cross section '" + this.description + "'");
 
         getPeer();
 
-        int i = 1, N = lines.size();
+        // int i = 1;
+        // final int N = this.lines.size();
 
-        for (ImportCrossSectionLine line: lines) {
+        for (final ImportCrossSectionLine line: this.lines) {
             line.storeDependencies();
-            log.info("  stored " + i + " lines. remaining: " + (N-i));
-            ++i;
+            // log.info(" stored " + i + " lines. remaining: " + (N-i));
+            // ++i;
         }
+        log.info(" lines stored: " + this.lines.size());
     }
 
     public CrossSection getPeer() {
 
-        if (peer == null) {
-            River r = river.getPeer();
-            TimeInterval t = timeInterval != null
-                ? timeInterval.getPeer()
-                : null;
+        if (this.peer == null) {
+            final River r = this.river.getPeer();
+            final TimeInterval t = (this.timeInterval != null) ? this.timeInterval.getPeer() : null;
 
-            Session session =
-                ImporterSession.getInstance().getDatabaseSession();
+            final Session session =
+                    ImporterSession.getInstance().getDatabaseSession();
 
-            Query query = session.createQuery(
-                "from CrossSection where " +
-                "river=:r and "            +
-                "timeInterval=:t and "     +
-                "description=:d");
+            final Query query = session.createQuery(
+                    "from CrossSection where " +
+                            "river=:r and "            +
+                            "timeInterval=:t and "     +
+                    "description=:d");
 
             query.setParameter("r", r);
             query.setParameter("t", t);
-            query.setParameter("d", description);
+            query.setParameter("d", this.description);
 
-            List<CrossSection> crossSections = query.list();
+            final List<CrossSection> crossSections = query.list();
             if (crossSections.isEmpty()) {
-                peer = new CrossSection(r, t, description);
-                session.save(peer);
+                this.peer = new CrossSection(r, t, this.description);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = crossSections.get(0);
+                this.peer = crossSections.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportCrossSectionLine.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportCrossSectionLine.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,18 +8,18 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.CrossSection;
-import org.dive4elements.river.model.CrossSectionPoint;
-import org.dive4elements.river.model.CrossSectionLine;
-
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import java.util.Comparator;
 import java.util.List;
-import java.util.Comparator;
 import java.util.Map;
 import java.util.TreeMap;
 
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.CrossSection;
+import org.dive4elements.river.model.CrossSectionLine;
+import org.dive4elements.river.model.CrossSectionPoint;
+import org.hibernate.Query;
+import org.hibernate.Session;
+
 /**
  * A CrossSectionLine (containing points) ready to be transformed into a mapped
  * object and written to db (used in importer).
@@ -27,39 +27,42 @@
 public class ImportCrossSectionLine
 {
     public static final Comparator<CrossSectionPoint> INDEX_CMP =
-        new Comparator<CrossSectionPoint>() {
-            public int compare(CrossSectionPoint a, CrossSectionPoint b) {
-                return a.getColPos().compareTo(b.getColPos());
-            }
-        };
+            new Comparator<CrossSectionPoint>() {
+        @Override
+        public int compare(final CrossSectionPoint a, final CrossSectionPoint b) {
+            return a.getColPos().compareTo(b.getColPos());
+        }
+    };
 
     protected Double km;
     protected ImportCrossSection crossSection;
     protected List<XY> points;
+    protected StoreMode storeMode;
 
     protected CrossSectionLine peer;
 
     public ImportCrossSectionLine() {
     }
 
-    public ImportCrossSectionLine(Double km, List<XY> points) {
+    public ImportCrossSectionLine(final Double km, final List<XY> points) {
         this.km     = km;
         this.points = points;
+        this.storeMode = StoreMode.NONE;
     }
 
     public ImportCrossSection getCrossSection() {
-        return crossSection;
+        return this.crossSection;
     }
 
-    public void setCrossSection(ImportCrossSection crossSection) {
+    public void setCrossSection(final ImportCrossSection crossSection) {
         this.crossSection = crossSection;
     }
 
     public Double getKm() {
-        return km;
+        return this.km;
     }
 
-    public void setKm(Double km) {
+    public void setKm(final Double km) {
         this.km = km;
     }
 
@@ -70,35 +73,37 @@
 
     /** Write a line and its points. */
     protected void storePoints() {
-        CrossSectionLine csl = getPeer();
-
-        Map<CrossSectionPoint, CrossSectionPoint> map =
-            new TreeMap<CrossSectionPoint, CrossSectionPoint>(INDEX_CMP);
+        final CrossSectionLine csl = getPeer();
+        if (this.storeMode == StoreMode.INSERT) {
+            insertPoints();
+            return;
+        }
+        final Map<CrossSectionPoint, CrossSectionPoint> map =
+                new TreeMap<>(INDEX_CMP);
 
         // Build index for faster (index) collision lookup.
-        List<CrossSectionPoint> ps = csl.getPoints();
+        final List<CrossSectionPoint> ps = csl.getPoints();
         if (ps != null) {
-            for (CrossSectionPoint point: ps) {
+            for (final CrossSectionPoint point: ps) {
                 map.put(point, point);
             }
         }
 
-        Session session =
-            ImporterSession.getInstance().getDatabaseSession();
+        final Session session = ImporterSession.getInstance().getDatabaseSession();
 
-        CrossSectionPoint key = new CrossSectionPoint();
+        final CrossSectionPoint key = new CrossSectionPoint();
 
         // Somehow it looks as if even with the map it is still possible that
         // multiple points with same id enter hibernate (and then violate a
         // constraint). -> TODO
-        for (XY xy: points) {
+        for (final XY xy: this.points) {
             key.setColPos(xy.getIndex());
             CrossSectionPoint csp = map.get(key);
             if (csp == null) { // create new
                 csp = new CrossSectionPoint(
-                    csl, key.getColPos(),
-                    Double.valueOf(xy.getX()),
-                    Double.valueOf(xy.getY()));
+                        csl, key.getColPos(),
+                        Double.valueOf(xy.getX()),
+                        Double.valueOf(xy.getY()));
             }
             else { // update old
                 csp.setX(Double.valueOf(xy.getX()));
@@ -108,29 +113,41 @@
         }
     }
 
+    /**
+     * Insert the points of a new line into the database without previously querying the database
+     */
+    private void insertPoints() {
+        final Session session = ImporterSession.getInstance().getDatabaseSession();
+        for (final XY xy : this.points) {
+            session.save(new CrossSectionPoint(getPeer(), xy.getIndex(), xy.getX(), xy.getY()));
+        }
+    }
+
     /** Pull database-mapped object from db, or create (and save) one. */
     public CrossSectionLine getPeer() {
-        if (peer == null) {
-            CrossSection cs = crossSection.getPeer();
-
-            Session session =
-                ImporterSession.getInstance().getDatabaseSession();
-
-            Query query = session.createQuery(
-                "from CrossSectionLine where crossSection=:cs and km=:km");
-            query.setParameter("cs", cs);
-            query.setParameter("km", km);
-
-            List<CrossSectionLine> lines = query.list();
-            if (lines.isEmpty()) {
-                peer = new CrossSectionLine(cs, km);
-                session.save(peer);
+        if (this.peer == null) {
+            final CrossSection cs = this.crossSection.getPeer();
+            final Session session = ImporterSession.getInstance().getDatabaseSession();
+            List<CrossSectionLine> lines;
+            if (this.crossSection.storeMode == StoreMode.INSERT)
+                lines = null;
+            else {
+                final Query query = session.createQuery("from CrossSectionLine where crossSection=:cs and km=:km");
+                query.setParameter("cs", cs);
+                query.setParameter("km", this.km);
+                lines = query.list();
+            }
+            if ((lines == null) || lines.isEmpty()) {
+                this.peer = new CrossSectionLine(cs, this.km);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = lines.get(0);
+                this.peer = lines.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModel.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModel.java	Sun Apr 08 18:07:06 2018 +0200
@@ -12,75 +12,75 @@
 import java.util.List;
 
 import org.apache.log4j.Logger;
-
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.DischargeZone;
 import org.dive4elements.river.model.FlowVelocityModel;
 import org.dive4elements.river.model.River;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 
 public class ImportFlowVelocityModel {
 
     private static final Logger log = Logger
-        .getLogger(ImportFlowVelocityModel.class);
+            .getLogger(ImportFlowVelocityModel.class);
 
     private String description;
 
     private ImportDischargeZone dischargeZone;
 
-    private List<ImportFlowVelocityModelValue> values;
+    private final List<ImportFlowVelocityModelValue> values;
+
+    protected StoreMode storeMode;
 
     private FlowVelocityModel peer;
 
     public ImportFlowVelocityModel() {
-        values = new ArrayList<ImportFlowVelocityModelValue>();
+        this.values = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
-    public ImportFlowVelocityModel(String description) {
+    public ImportFlowVelocityModel(final String description) {
         this();
-
         this.description = description;
     }
 
-    public ImportFlowVelocityModel(ImportDischargeZone dischargeZone,
-        String description) {
+    public ImportFlowVelocityModel(final ImportDischargeZone dischargeZone,
+            final String description) {
         this();
-
         this.dischargeZone = dischargeZone;
         this.description = description;
     }
 
-    public void setDischargeZone(ImportDischargeZone dischargeZone) {
+    public void setDischargeZone(final ImportDischargeZone dischargeZone) {
         this.dischargeZone = dischargeZone;
     }
 
-    public void setDescription(String description) {
+    public void setDescription(final String description) {
         this.description = description;
     }
 
-    public void addValue(ImportFlowVelocityModelValue value) {
+    public void addValue(final ImportFlowVelocityModelValue value) {
         this.values.add(value);
     }
 
-    public void storeDependencies(River river) {
+    public void storeDependencies(final River river) {
         log.debug("store dependencies");
 
-        if (dischargeZone == null) {
+        if (this.dischargeZone == null) {
             log.warn("skip flow velocity model: No discharge zone specified.");
             return;
         }
 
-        dischargeZone.storeDependencies(river);
+        this.dischargeZone.storeDependencies(river);
 
-        FlowVelocityModel peer = getPeer(river);
+        final FlowVelocityModel peer = getPeer(river);
 
         if (peer != null) {
             int i = 0;
 
-            for (ImportFlowVelocityModelValue value : values) {
-                value.storeDependencies(peer);
+            for (final ImportFlowVelocityModelValue value : this.values) {
+                value.storeDependencies(peer, this.storeMode);
                 i++;
             }
 
@@ -88,30 +88,32 @@
         }
     }
 
-    public FlowVelocityModel getPeer(River river) {
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
+    public FlowVelocityModel getPeer(final River river) {
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
 
-            DischargeZone zone = dischargeZone.getPeer(river);
+            final DischargeZone zone = this.dischargeZone.getPeer(river);
 
-            Query query = session.createQuery("from FlowVelocityModel where "
-                + "   dischargeZone=:dischargeZone");
+            final Query query = session.createQuery("from FlowVelocityModel where "
+                    + "   dischargeZone=:dischargeZone");
 
             query.setParameter("dischargeZone", zone);
 
-            List<FlowVelocityModel> model = query.list();
+            final List<FlowVelocityModel> model = query.list();
 
             if (model.isEmpty()) {
-                peer = new FlowVelocityModel(zone, description);
-                session.save(peer);
+                this.peer = new FlowVelocityModel(zone, this.description);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = model.get(0);
+                this.peer = model.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModelValue.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportFlowVelocityModelValue.java	Sun Apr 08 18:07:06 2018 +0200
@@ -9,34 +9,33 @@
 package org.dive4elements.river.importer;
 
 import java.math.BigDecimal;
-
 import java.util.List;
 
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.FlowVelocityModel;
 import org.dive4elements.river.model.FlowVelocityModelValue;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 
 public class ImportFlowVelocityModelValue {
 
-    private BigDecimal station;
-    private BigDecimal q;
-    private BigDecimal totalChannel;
-    private BigDecimal mainChannel;
-    private BigDecimal shearStress;
+    private final BigDecimal station;
+    private final BigDecimal q;
+    private final BigDecimal totalChannel;
+    private final BigDecimal mainChannel;
+    private final BigDecimal shearStress;
 
     private FlowVelocityModelValue peer;
 
 
     public ImportFlowVelocityModelValue(
-        BigDecimal station,
-        BigDecimal q,
-        BigDecimal totalChannel,
-        BigDecimal mainChannel,
-        BigDecimal shearStress
-    ) {
+            final BigDecimal station,
+            final BigDecimal q,
+            final BigDecimal totalChannel,
+            final BigDecimal mainChannel,
+            final BigDecimal shearStress
+            ) {
         this.station      = station;
         this.q            = q;
         this.totalChannel = totalChannel;
@@ -45,39 +44,41 @@
     }
 
 
-    public void storeDependencies(FlowVelocityModel model) {
-        getPeer(model);
+    public void storeDependencies(final FlowVelocityModel model, final StoreMode parentStoreMode) {
+        getPeer(model, parentStoreMode);
     }
 
 
-    public FlowVelocityModelValue getPeer(FlowVelocityModel model) {
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
+    public FlowVelocityModelValue getPeer(final FlowVelocityModel model, final StoreMode parentStoreMode) {
+        if (this.peer == null) {
+            List<FlowVelocityModelValue> values;
+            final Session session = ImporterSession.getInstance().getDatabaseSession();
+            if (parentStoreMode == StoreMode.INSERT)
+                values = null;
+            else {
+                final Query query = session.createQuery(
+                        "from FlowVelocityModelValue where " +
+                                "   flowVelocity=:model and " +
+                                "   station between :station - 0.00001 and :station + 0.00001"
+                        );
 
-            Query query = session.createQuery(
-                "from FlowVelocityModelValue where " +
-                "   flowVelocity=:model and " +
-                "   station between :station - 0.00001 and :station + 0.00001"
-            );
+                query.setParameter("model", model);
+                query.setParameter("station", this.station.doubleValue());
 
-            query.setParameter("model", model);
-            query.setParameter("station", station.doubleValue());
-
-            List<FlowVelocityModelValue> values = query.list();
+                values = query.list();
+            }
+            if ((values == null) || values.isEmpty()) {
+                this.peer = new FlowVelocityModelValue(
+                        model, this.station, this.q, this.totalChannel, this.mainChannel, this.shearStress);
 
-            if (values.isEmpty()) {
-                peer = new FlowVelocityModelValue(
-                    model, station, q, totalChannel, mainChannel, shearStress);
-
-                session.save(peer);
+                session.save(this.peer);
             }
             else {
-                peer = values.get(0);
+                this.peer = values.get(0);
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportHYK.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportHYK.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,16 +8,15 @@
 
 package org.dive4elements.river.importer;
 
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.HYK;
 import org.dive4elements.river.model.River;
-
-import java.util.List;
-import java.util.ArrayList;
-
+import org.hibernate.Query;
 import org.hibernate.Session;
-import org.hibernate.Query;
-
-import org.apache.log4j.Logger;
 
 public class ImportHYK
 {
@@ -28,61 +27,66 @@
 
     protected List<ImportHYKEntry> entries;
 
+    protected StoreMode storeMode;
+
     protected HYK peer;
 
     public ImportHYK() {
-        entries = new ArrayList<ImportHYKEntry>();
+        this.entries = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
-    public ImportHYK(ImportRiver river, String description) {
+    public ImportHYK(final ImportRiver river, final String description) {
         this();
         this.river       = river;
         this.description = description;
     }
 
     public ImportRiver getRiver() {
-        return river;
+        return this.river;
     }
 
-    public void setRiver(ImportRiver river) {
+    public void setRiver(final ImportRiver river) {
         this.river = river;
     }
 
-    public void addEntry(ImportHYKEntry entry) {
-        entries.add(entry);
+    public void addEntry(final ImportHYKEntry entry) {
+        this.entries.add(entry);
         entry.setHYK(this);
     }
 
     public void storeDependencies() {
-        log.info("store HYK '" + description + "'");
+        log.info("store HYK '" + this.description + "'");
         getPeer();
-        for (int i = 0, N = entries.size(); i < N; ++i) {
-            ImportHYKEntry entry = entries.get(i);
+        for (int i = 0, N = this.entries.size(); i < N; ++i) {
+            final ImportHYKEntry entry = this.entries.get(i);
             log.info("  store km " + entry.getKm() +
-                " (" + (i+1) + " of " + N + ")");
+                    " (" + (i+1) + " of " + N + ")");
             entry.storeDependencies();
         }
     }
 
     public HYK getPeer() {
-        if (peer == null) {
-            River r = river.getPeer();
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from HYK where river=:river and description=:description");
+        if (this.peer == null) {
+            final River r = this.river.getPeer();
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            final Query query = session.createQuery(
+                    "from HYK where river=:river and description=:description");
             query.setParameter("river", r);
-            query.setParameter("description", description);
-            List<HYK> hyks = query.list();
+            query.setParameter("description", this.description);
+            final List<HYK> hyks = query.list();
             if (hyks.isEmpty()) {
-                peer = new HYK(r, description);
-                session.save(peer);
+                this.peer = new HYK(r, this.description);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = hyks.get(0);
+                this.peer = hyks.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportHYKEntry.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportHYKEntry.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,17 +8,16 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.HYKEntry;
-import org.dive4elements.river.model.HYK;
-
+import java.math.BigDecimal;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
-import java.util.ArrayList;
 
-import java.math.BigDecimal;
-
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.HYK;
+import org.dive4elements.river.model.HYKEntry;
+import org.hibernate.Query;
 import org.hibernate.Session;
-import org.hibernate.Query;
 
 public class ImportHYKEntry
 {
@@ -28,17 +27,20 @@
 
     protected List<ImportHYKFormation> formations;
 
+    protected StoreMode storeMode;
+
     protected HYKEntry peer;
 
     public ImportHYKEntry() {
-        formations = new ArrayList<ImportHYKFormation>();
+        this.formations = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
     public ImportHYKEntry(
-        ImportHYK  hyk,
-        BigDecimal km,
-        Date       measure
-    ) {
+            final ImportHYK  hyk,
+            final BigDecimal km,
+            final Date       measure
+            ) {
         this();
         this.hyk     = hyk;
         this.km      = km;
@@ -46,56 +48,63 @@
     }
 
     public ImportHYK getHYK() {
-        return hyk;
+        return this.hyk;
     }
 
-    public void setHYK(ImportHYK hyk) {
+    public void setHYK(final ImportHYK hyk) {
         this.hyk = hyk;
     }
 
     public BigDecimal getKm() {
-        return km;
+        return this.km;
     }
 
-    public void setKm(BigDecimal km) {
+    public void setKm(final BigDecimal km) {
         this.km = km;
     }
 
-    public void addFormation(ImportHYKFormation formation) {
-        int numFormation = formations.size();
-        formations.add(formation);
+    public void addFormation(final ImportHYKFormation formation) {
+        final int numFormation = this.formations.size();
+        this.formations.add(formation);
         formation.setFormationNum(numFormation);
         formation.setEntry(this);
     }
 
     public void storeDependencies() {
         getPeer();
-        for (ImportHYKFormation formation: formations) {
+        for (final ImportHYKFormation formation: this.formations) {
             formation.storeDependencies();
         }
     }
 
     public HYKEntry getPeer() {
-        if (peer == null) {
-            HYK h = hyk.getPeer();
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from HYKEntry where HYK=:hyk " +
-                "and km=:km and measure=:measure");
-            query.setParameter("hyk", h);
-            query.setParameter("km", km);
-            query.setParameter("measure", measure);
-            List<HYKEntry> entries = query.list();
-            if (entries.isEmpty()) {
-                peer = new HYKEntry(h, km, measure);
-                session.save(peer);
+        if (this.peer == null) {
+            final HYK h = this.hyk.getPeer();
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            List<HYKEntry> entries;
+            if (this.hyk.storeMode == StoreMode.INSERT)
+                entries = null;
+            else {
+                final Query query = session.createQuery(
+                        "from HYKEntry where HYK=:hyk " +
+                        "and km=:km and measure=:measure");
+                query.setParameter("hyk", h);
+                query.setParameter("km", this.km);
+                query.setParameter("measure", this.measure);
+                entries = query.list();
+            }
+            if ((entries == null) || entries.isEmpty()) {
+                this.peer = new HYKEntry(h, this.km, this.measure);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = entries.get(0);
+                this.peer = entries.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportHYKFlowZone.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportHYKFlowZone.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,16 +8,15 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.HYKFormation;
+import java.math.BigDecimal;
+import java.util.List;
+
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.HYKFlowZone;
 import org.dive4elements.river.model.HYKFlowZoneType;
-
-import org.hibernate.Session;
+import org.dive4elements.river.model.HYKFormation;
 import org.hibernate.Query;
-
-import java.util.List;
-
-import java.math.BigDecimal;
+import org.hibernate.Session;
 
 public class ImportHYKFlowZone
 {
@@ -32,11 +31,11 @@
     }
 
     public ImportHYKFlowZone(
-        ImportHYKFormation    formation,
-        ImportHYKFlowZoneType type,
-        BigDecimal            a,
-        BigDecimal            b
-    ) {
+            final ImportHYKFormation    formation,
+            final ImportHYKFlowZoneType type,
+            final BigDecimal            a,
+            final BigDecimal            b
+            ) {
         this.formation = formation;
         this.type      = type;
         this.a         = a;
@@ -44,10 +43,10 @@
     }
 
     public ImportHYKFormation getFormation() {
-        return formation;
+        return this.formation;
     }
 
-    public void setFormation(ImportHYKFormation formation) {
+    public void setFormation(final ImportHYKFormation formation) {
         this.formation = formation;
     }
 
@@ -56,29 +55,34 @@
     }
 
     public HYKFlowZone getPeer() {
-        if (peer == null) {
-            HYKFormation    f = formation.getPeer();
-            HYKFlowZoneType t = type.getPeer();
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from HYKFlowZone where formation=:formation " +
-                "and type=:type and a=:a and b=:b");
-            query.setParameter("formation", f);
-            query.setParameter("type", t);
-            query.setParameter("a", a);
-            query.setParameter("b", b);
-            List<HYKFlowZone> zones = query.list();
-            if (zones.isEmpty()) {
-                peer = new HYKFlowZone(f, t, a, b);
-                session.save(peer);
+        if (this.peer == null) {
+            final HYKFormation    f = this.formation.getPeer();
+            final HYKFlowZoneType t = this.type.getPeer();
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            List<HYKFlowZone> zones;
+            if (this.formation.storeMode == StoreMode.INSERT)
+                zones = null;
+            {
+                final Query query = session.createQuery(
+                        "from HYKFlowZone where formation=:formation " +
+                        "and type=:type and a=:a and b=:b");
+                query.setParameter("formation", f);
+                query.setParameter("type", t);
+                query.setParameter("a", this.a);
+                query.setParameter("b", this.b);
+                zones = query.list();
+            }
+            if ((zones == null) || zones.isEmpty()) {
+                this.peer = new HYKFlowZone(f, t, this.a, this.b);
+                session.save(this.peer);
             }
             else {
-                peer = zones.get(0);
+                this.peer = zones.get(0);
             }
 
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportHYKFormation.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportHYKFormation.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,16 +8,15 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.HYKFormation;
-import org.dive4elements.river.model.HYKEntry;
-
+import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.hibernate.Session;
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.HYKEntry;
+import org.dive4elements.river.model.HYKFormation;
 import org.hibernate.Query;
-
-import java.math.BigDecimal;
+import org.hibernate.Session;
 
 public class ImportHYKFormation
 {
@@ -31,21 +30,24 @@
 
     protected List<ImportHYKFlowZone> zones;
 
+    protected StoreMode storeMode;
+
     protected HYKFormation peer;
 
     public ImportHYKFormation() {
-        zones = new ArrayList<ImportHYKFlowZone>();
+        this.zones = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
     public ImportHYKFormation(
-        int            formationNum,
-        ImportHYKEntry entry,
-        BigDecimal     top,
-        BigDecimal     bottom,
-        BigDecimal     distanceVL,
-        BigDecimal     distanceHF,
-        BigDecimal     distanceVR
-    ) {
+            final int            formationNum,
+            final ImportHYKEntry entry,
+            final BigDecimal     top,
+            final BigDecimal     bottom,
+            final BigDecimal     distanceVL,
+            final BigDecimal     distanceHF,
+            final BigDecimal     distanceVR
+            ) {
         this();
         this.formationNum = formationNum;
         this.entry        = entry;
@@ -56,103 +58,110 @@
         this.distanceVR   = distanceVR;
     }
 
-    public void addFlowZone(ImportHYKFlowZone zone) {
-        zones.add(zone);
+    public void addFlowZone(final ImportHYKFlowZone zone) {
+        this.zones.add(zone);
         zone.setFormation(this);
     }
 
     public int getFormationNum() {
-        return formationNum;
+        return this.formationNum;
     }
 
-    public void setFormationNum(int formationNum) {
+    public void setFormationNum(final int formationNum) {
         this.formationNum = formationNum;
     }
 
     public ImportHYKEntry getEntry() {
-        return entry;
+        return this.entry;
     }
 
-    public void setEntry(ImportHYKEntry entry) {
+    public void setEntry(final ImportHYKEntry entry) {
         this.entry = entry;
     }
 
     public BigDecimal getTop() {
-        return top;
+        return this.top;
     }
 
-    public void setTop(BigDecimal top) {
+    public void setTop(final BigDecimal top) {
         this.top = top;
     }
 
     public BigDecimal getBottom() {
-        return bottom;
+        return this.bottom;
     }
 
-    public void setBottom(BigDecimal bottom) {
+    public void setBottom(final BigDecimal bottom) {
         this.bottom = bottom;
     }
 
     public BigDecimal getDistanceVL() {
-        return distanceVL;
+        return this.distanceVL;
     }
 
-    public void setDistanceVL(BigDecimal distanceVL) {
+    public void setDistanceVL(final BigDecimal distanceVL) {
         this.distanceVL = distanceVL;
     }
 
     public BigDecimal getDistanceHF() {
-        return distanceHF;
+        return this.distanceHF;
     }
 
-    public void setDistanceHF(BigDecimal distanceHF) {
+    public void setDistanceHF(final BigDecimal distanceHF) {
         this.distanceHF = distanceHF;
     }
 
     public BigDecimal getDistanceVR() {
-        return distanceVR;
+        return this.distanceVR;
     }
 
-    public void setDistanceVR(BigDecimal distanceVR) {
+    public void setDistanceVR(final BigDecimal distanceVR) {
         this.distanceVR = distanceVR;
     }
 
     public void storeDependencies() {
         getPeer();
-        for (ImportHYKFlowZone zone: zones) {
+        for (final ImportHYKFlowZone zone: this.zones) {
             zone.storeDependencies();
         }
     }
 
     public HYKFormation getPeer() {
-        if (peer == null) {
-            HYKEntry e = entry.getPeer();
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from HYKFormation where formationNum=:formationNum " +
-                "and entry=:entry and top=:top and bottom=:bottom " +
-                "and distanceVL=:distanceVL and distanceHF=:distanceHF " +
-                "and distanceVR=:distanceVR");
-            query.setParameter("formationNum", formationNum);
-            query.setParameter("entry", e);
-            query.setParameter("top", top);
-            query.setParameter("bottom", bottom);
-            query.setParameter("distanceVL", distanceVL);
-            query.setParameter("distanceHF", distanceHF);
-            query.setParameter("distanceVR", distanceVR);
-            List<HYKFormation> formations = query.list();
-            if (formations.isEmpty()) {
-                peer = new HYKFormation(
-                    formationNum, e, top, bottom,
-                    distanceVL, distanceHF, distanceVR);
-                session.save(peer);
+        if (this.peer == null) {
+            final HYKEntry e = this.entry.getPeer();
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            List<HYKFormation> formations;
+            if (this.entry.storeMode == StoreMode.INSERT)
+                formations = null;
+            else {
+                final Query query = session.createQuery(
+                        "from HYKFormation where formationNum=:formationNum " +
+                                "and entry=:entry and top=:top and bottom=:bottom " +
+                                "and distanceVL=:distanceVL and distanceHF=:distanceHF " +
+                        "and distanceVR=:distanceVR");
+                query.setParameter("formationNum", this.formationNum);
+                query.setParameter("entry", e);
+                query.setParameter("top", this.top);
+                query.setParameter("bottom", this.bottom);
+                query.setParameter("distanceVL", this.distanceVL);
+                query.setParameter("distanceHF", this.distanceHF);
+                query.setParameter("distanceVR", this.distanceVR);
+                formations = query.list();
+            }
+            if ((formations == null) || formations.isEmpty()) {
+                this.peer = new HYKFormation(
+                        this.formationNum, e, this.top, this.bottom,
+                        this.distanceVL, this.distanceHF, this.distanceVR);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = formations.get(0);
+                this.peer = formations.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportPorosity.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportPorosity.java	Sun Apr 08 18:07:06 2018 +0200
@@ -12,12 +12,12 @@
 import java.util.List;
 
 import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.Porosity;
+import org.dive4elements.river.model.River;
 import org.hibernate.Query;
 import org.hibernate.Session;
 
-import org.dive4elements.river.model.River;
-import org.dive4elements.river.model.Porosity;
-
 
 public class ImportPorosity {
 
@@ -33,82 +33,88 @@
 
     protected List<ImportPorosityValue> values;
 
-    public ImportPorosity(String description) {
+    protected StoreMode storeMode;
+
+    public ImportPorosity(final String description) {
         this.description = description;
-        this.values = new ArrayList<ImportPorosityValue>();
+        this.values = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
     public String getDescription() {
-        return description;
+        return this.description;
     }
 
-    public void setDepth(ImportDepth depth) {
+    public void setDepth(final ImportDepth depth) {
         this.depth = depth;
     }
 
-    public void setTimeInterval(ImportTimeInterval importTimeInterval) {
+    public void setTimeInterval(final ImportTimeInterval importTimeInterval) {
         this.timeInterval = importTimeInterval;
     }
 
-    public void addValue(ImportPorosityValue value) {
-        values.add(value);
+    public void addValue(final ImportPorosityValue value) {
+        this.values.add(value);
     }
 
-    public void storeDependencies(River river) {
-        log.info("store dependencies");
+    public void storeDependencies(final River river) {
+        log.info("store dependencies for '" + getDescription() + "'");
 
-        if (depth != null) {
-            depth.storeDependencies();
+        if (this.depth != null) {
+            this.depth.storeDependencies();
         }
 
-        Porosity peer = getPeer(river);
+        final Porosity peer = getPeer(river);
 
         if (peer != null) {
-            log.info("store porosity values.");
-            for (ImportPorosityValue value : values) {
-                value.storeDependencies(peer);
+            // log.info("store porosity values.");
+            for (final ImportPorosityValue value : this.values) {
+                value.storeDependencies(peer, this.storeMode);
             }
+            log.info("Porosity values processed: " + this.values.size());
         }
     }
 
-    public Porosity getPeer(River river) {
-        log.info("get peer");
+    public Porosity getPeer(final River river) {
+        // log.info("get peer");
 
-        if (depth == null) {
-            log.warn("cannot store porosity '" + description
-                + "': no depth");
+        if (this.depth == null) {
+            log.warn("cannot store porosity '" + this.description
+                    + "': no depth");
             return null;
         }
 
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
 
-            Query query = session.createQuery("from Porosity where "
-                + "   river=:river and "
-                + "   depth=:depth and "
-                + "   description=:description");
+            final Query query = session.createQuery("from Porosity where "
+                    + "   river=:river and "
+                    + "   depth=:depth and "
+                    + "   description=:description");
 
             query.setParameter("river", river);
-            query.setParameter("depth", depth.getPeer());
-            query.setParameter("description", description);
+            query.setParameter("depth", this.depth.getPeer());
+            query.setParameter("description", this.description);
 
-            List<Porosity> porosity = query.list();
+            final List<Porosity> porosity = query.list();
 
             if (porosity.isEmpty()) {
                 log.debug("Create new Porosity DB instance.");
 
-                peer = new Porosity(river, depth.getPeer(),
-                    description, timeInterval.getPeer());
+                this.peer = new Porosity(river, this.depth.getPeer(),
+                        this.description, this.timeInterval.getPeer());
 
-                session.save(peer);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = porosity.get(0);
+                this.peer = porosity.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportPorosityValue.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportPorosityValue.java	Sun Apr 08 18:07:06 2018 +0200
@@ -9,22 +9,20 @@
 package org.dive4elements.river.importer;
 
 import java.math.BigDecimal;
-
 import java.util.List;
 
 import org.apache.log4j.Logger;
-
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.Porosity;
 import org.dive4elements.river.model.PorosityValue;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 
 public class ImportPorosityValue {
 
     private static final Logger log =
-        Logger.getLogger(ImportPorosityValue.class);
+            Logger.getLogger(ImportPorosityValue.class);
 
 
     protected PorosityValue peer;
@@ -39,11 +37,11 @@
 
 
     public ImportPorosityValue(
-        BigDecimal station,
-        BigDecimal shoreOffset,
-        BigDecimal porosity,
-        String     description
-    ) {
+            final BigDecimal station,
+            final BigDecimal shoreOffset,
+            final BigDecimal porosity,
+            final String     description
+            ) {
         this.station     = station;
         this.shoreOffset = shoreOffset;
         this.porosity    = porosity;
@@ -51,53 +49,57 @@
     }
 
 
-    public void storeDependencies(Porosity porosity) {
-        log.info("store dependencies");
+    public void storeDependencies(final Porosity porosity, final StoreMode parentStoreMode) {
+        // log.info("store dependencies");
 
-        getPeer(porosity);
+        getPeer(porosity, parentStoreMode);
     }
 
 
-    public PorosityValue getPeer(Porosity porosity) {
+    public PorosityValue getPeer(final Porosity porosity, final StoreMode parentStoreMode) {
         log.info("get peer");
 
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-
-            Query query = session.createQuery(
-                "from PorosityValue "
-                + "where porosity=:porosity "
-                + "and station between :station - 0.0001f "
-                + "    and :station + 0.0001f "
-                + "and porosityValue between :poros -0.0001f "
-                + "    and :poros + 0.0001f "
-                + "and description=:description");
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            List<PorosityValue> values;
+            if (parentStoreMode == StoreMode.INSERT)
+                values = null;
+            else {
+                final Query query = session.createQuery(
+                        "from PorosityValue "
+                                + "where porosity=:porosity "
+                                + "and station between :station - 0.0001f "
+                                + "    and :station + 0.0001f "
+                                + "and porosityValue between :poros -0.0001f "
+                                + "    and :poros + 0.0001f "
+                                + "and description=:description");
 
-            query.setParameter("porosity", porosity);
-            query.setParameter("station", station.floatValue());
-            query.setParameter("poros", this.porosity.floatValue());
-            query.setParameter("description", description);
+                query.setParameter("porosity", porosity);
+                query.setParameter("station", this.station.floatValue());
+                query.setParameter("poros", this.porosity.floatValue());
+                query.setParameter("description", this.description);
 
-            List<PorosityValue> values = query.list();
-            if (values.isEmpty()) {
-                log.debug("Create new PorosityValue DB instance.");
+                values = query.list();
+            }
+            if ((values == null) || values.isEmpty()) {
+                // log.debug("Create new PorosityValue DB instance.");
 
-                peer = new PorosityValue(
-                    porosity,
-                    station,
-                    shoreOffset,
-                    this.porosity,
-                    description);
+                this.peer = new PorosityValue(
+                        porosity,
+                        this.station,
+                        this.shoreOffset,
+                        this.porosity,
+                        this.description);
 
-                session.save(peer);
+                session.save(this.peer);
             }
             else {
-                peer = values.get(0);
+                this.peer = values.get(0);
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoad.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoad.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,9 +8,11 @@
 
 package org.dive4elements.river.importer;
 
+import java.util.ArrayList;
 import java.util.List;
-import java.util.ArrayList;
 
+import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.GrainFraction;
 import org.dive4elements.river.model.SedimentLoad;
 import org.dive4elements.river.model.TimeInterval;
@@ -19,6 +21,8 @@
 
 public class ImportSedimentLoad
 {
+    private static Logger log = Logger.getLogger(ImportSedimentLoad.class);
+
     private SedimentLoad peer;
 
     private ImportGrainFraction grainFraction;
@@ -27,92 +31,98 @@
     private String              description;
     private Integer             kind;
 
-    private List<ImportSedimentLoadValue> values;
+    private final List<ImportSedimentLoadValue> values;
+
+    protected StoreMode storeMode;
 
     public ImportSedimentLoad() {
-        this.values = new ArrayList<ImportSedimentLoadValue>();
+        this.values = new ArrayList<>();
     }
 
     public ImportSedimentLoad(
-        ImportGrainFraction grainFraction,
-        ImportTimeInterval  timeInterval,
-        ImportTimeInterval  sqTimeInterval,
-        String              description,
-        Integer             kind
-    ) {
+            final ImportGrainFraction grainFraction,
+            final ImportTimeInterval  timeInterval,
+            final ImportTimeInterval  sqTimeInterval,
+            final String              description,
+            final Integer             kind
+            ) {
         this.grainFraction  = grainFraction;
         this.timeInterval   = timeInterval;
         this.sqTimeInterval = sqTimeInterval;
         this.description    = description;
         this.kind           = kind;
 
-        this.values = new ArrayList<ImportSedimentLoadValue>();
+        this.values = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
-    public void addValue(ImportSedimentLoadValue value) {
-        values.add(value);
+    public void addValue(final ImportSedimentLoadValue value) {
+        this.values.add(value);
     }
 
     public void storeDependencies() {
-        grainFraction.getPeer();
-        timeInterval.getPeer();
+        log.info("store dependencies for '" + this.description + "'");
+        this.grainFraction.getPeer();
+        this.timeInterval.getPeer();
 
-        if (sqTimeInterval != null) {
-            sqTimeInterval.getPeer();
+        if (this.sqTimeInterval != null) {
+            this.sqTimeInterval.getPeer();
         }
 
         getPeer();
 
-        for (ImportSedimentLoadValue value : values) {
-            value.storeDependencies(peer);
+        for (final ImportSedimentLoadValue value : this.values) {
+            value.storeDependencies(this.peer, this.storeMode);
         }
-
+        log.info("Values processed: " + this.values.size());
     }
 
     public SedimentLoad getPeer() {
 
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-
-            String sqtquery = sqTimeInterval == null
-                ? "sq_time_interval_id is null"
-                : "sqTimeInterval = :sqTimeInterval";
-            Query query = session.createQuery(
-                "from SedimentLoad where " +
-                "   grainFraction = :grainFraction and " +
-                "   timeInterval = :timeInterval and " +
-                "   description = :description and " +
-                "   kind = :kind and " +
-                    sqtquery);
-
-            GrainFraction gf = grainFraction.getPeer();
-            TimeInterval  ti = timeInterval.getPeer();
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
 
-            TimeInterval sqti = sqTimeInterval != null
-                ? sqTimeInterval.getPeer()
-                : null;
-
-            query.setParameter("grainFraction", gf);
-            query.setParameter("timeInterval", ti);
+            final String sqtquery = this.sqTimeInterval == null
+                    ? "sq_time_interval_id is null"
+                            : "sqTimeInterval = :sqTimeInterval";
+            final Query query = session.createQuery(
+                    "from SedimentLoad where " +
+                            "   grainFraction = :grainFraction and " +
+                            "   timeInterval = :timeInterval and " +
+                            "   description = :description and " +
+                            "   kind = :kind and " +
+                            sqtquery);
 
-            if (sqti != null) {
-                query.setParameter("sqTimeInterval", sqti);
-            }
-            query.setParameter("description", description);
-            query.setParameter("kind", kind);
+            final GrainFraction gf = this.grainFraction.getPeer();
+            final TimeInterval  ti = this.timeInterval.getPeer();
 
-            List<SedimentLoad> loads = query.list();
-            if (loads.isEmpty()) {
-                peer = new SedimentLoad(gf, ti, sqti, description, kind);
-                session.save(peer);
-            }
-            else {
-                peer = loads.get(0);
-            }
+            final TimeInterval sqti = this.sqTimeInterval != null
+                    ? this.sqTimeInterval.getPeer()
+                            : null;
+
+                    query.setParameter("grainFraction", gf);
+                    query.setParameter("timeInterval", ti);
+
+                    if (sqti != null) {
+                        query.setParameter("sqTimeInterval", sqti);
+                    }
+                    query.setParameter("description", this.description);
+                    query.setParameter("kind", this.kind);
+
+                    final List<SedimentLoad> loads = query.list();
+                    if (loads.isEmpty()) {
+                        this.peer = new SedimentLoad(gf, ti, sqti, this.description, this.kind);
+                        session.save(this.peer);
+                        this.storeMode = StoreMode.INSERT;
+                    }
+                    else {
+                        this.peer = loads.get(0);
+                        this.storeMode = StoreMode.UPDATE;
+                    }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLS.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLS.java	Sun Apr 08 18:07:06 2018 +0200
@@ -12,15 +12,14 @@
 import java.util.List;
 
 import org.apache.log4j.Logger;
-
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.GrainFraction;
 import org.dive4elements.river.model.River;
 import org.dive4elements.river.model.SedimentLoadLS;
 import org.dive4elements.river.model.TimeInterval;
 import org.dive4elements.river.model.Unit;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 
 public class ImportSedimentLoadLS {
@@ -35,53 +34,56 @@
 
     private ImportTimeInterval sqTimeInterval;
 
-    private String description;
+    private final String description;
 
     private Integer kind;
 
-    private List<ImportSedimentLoadLSValue> values;
+    private final List<ImportSedimentLoadLSValue> values;
+
+    protected StoreMode storeMode;
 
     private SedimentLoadLS peer;
 
-    public ImportSedimentLoadLS(String description) {
-        this.values = new ArrayList<ImportSedimentLoadLSValue>();
+    public ImportSedimentLoadLS(final String description) {
+        this.values = new ArrayList<>();
         this.description = description;
+        this.storeMode = StoreMode.NONE;
     }
 
-    public void setTimeInterval(ImportTimeInterval timeInterval) {
+    public void setTimeInterval(final ImportTimeInterval timeInterval) {
         this.timeInterval = timeInterval;
     }
 
-    public void setSQTimeInterval(ImportTimeInterval sqTimeInterval) {
+    public void setSQTimeInterval(final ImportTimeInterval sqTimeInterval) {
         this.sqTimeInterval = sqTimeInterval;
     }
 
-    public void setUnit(ImportUnit unit) {
+    public void setUnit(final ImportUnit unit) {
         this.unit = unit;
     }
 
-    public void setGrainFraction(ImportGrainFraction grainFraction) {
+    public void setGrainFraction(final ImportGrainFraction grainFraction) {
         this.grainFraction = grainFraction;
     }
 
-    public void setKind(Integer kind) {
+    public void setKind(final Integer kind) {
         this.kind = kind;
     }
 
-    public void addValue(ImportSedimentLoadLSValue value) {
+    public void addValue(final ImportSedimentLoadLSValue value) {
         this.values.add(value);
     }
 
-    public void storeDependencies(River river) {
-        log.debug("store dependencies");
+    public void storeDependencies(final River river) {
+        log.info("store dependencies for '" + this.description + "'");
 
-        SedimentLoadLS peer = getPeer(river);
+        final SedimentLoadLS peer = getPeer(river);
 
         if (peer != null) {
             int i = 0;
 
-            for (ImportSedimentLoadLSValue value : values) {
-                value.storeDependencies(peer);
+            for (final ImportSedimentLoadLSValue value : this.values) {
+                value.storeDependencies(peer, this.storeMode);
                 i++;
             }
 
@@ -89,40 +91,38 @@
         }
     }
 
-    public SedimentLoadLS getPeer(River river) {
+    public SedimentLoadLS getPeer(final River river) {
         log.debug("get peer");
 
-        GrainFraction gf = grainFraction != null ? grainFraction.getPeer()
-            : null;
+        final GrainFraction gf = this.grainFraction != null ? this.grainFraction.getPeer()
+                : null;
 
-        Unit u = unit != null ? unit.getPeer() : null;
+        final Unit u = this.unit != null ? this.unit.getPeer() : null;
 
-        TimeInterval ti = timeInterval != null ? timeInterval.getPeer() : null;
-        TimeInterval sqti = sqTimeInterval != null
-                ? sqTimeInterval.getPeer()
-                : null;
+        final TimeInterval ti = (this.timeInterval != null) ? this.timeInterval.getPeer() : null;
+        final TimeInterval sqti = (this.sqTimeInterval != null) ? this.sqTimeInterval.getPeer() : null;
 
         if (ti == null || u == null) {
             log.warn(
-                "Skip invalid SedimentLoadLS: time interval or unit null!");
+                    "Skip invalid SedimentLoadLS: time interval or unit null!");
             return null;
         }
 
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
 
-            String sqtquery = sqTimeInterval == null ?
-                "sq_time_interval_id is null" :
-                "sqTimeInterval = :sqTimeInterval";
-            Query query = session.createQuery("from SedimentLoadLS where "
-                + "   river=:river and "
-                + "   grainFraction=:grainFraction and "
-                + "   unit=:unit and "
-                + "   timeInterval=:timeInterval and "
-                + "   description=:description and "
-                + "   kind = :kind and " +
-                      sqtquery);
+            final String sqtquery = this.sqTimeInterval == null ?
+                    "sq_time_interval_id is null" :
+                        "sqTimeInterval = :sqTimeInterval";
+            final Query query = session.createQuery("from SedimentLoadLS where "
+                    + "   river=:river and "
+                    + "   grainFraction=:grainFraction and "
+                    + "   unit=:unit and "
+                    + "   timeInterval=:timeInterval and "
+                    + "   description=:description and "
+                    + "   kind = :kind and " +
+                    sqtquery);
 
             query.setParameter("river", river);
             query.setParameter("grainFraction", gf);
@@ -131,23 +131,25 @@
             if (sqti != null) {
                 query.setParameter("sqTimeInterval", sqti);
             }
-            query.setParameter("description", description);
-            query.setParameter("kind", kind);
+            query.setParameter("description", this.description);
+            query.setParameter("kind", this.kind);
 
-            List<SedimentLoadLS> loads = query.list();
+            final List<SedimentLoadLS> loads = query.list();
             if (loads.isEmpty()) {
                 log.debug("create new SedimentLoadLS");
 
-                peer = new SedimentLoadLS(river, u, ti, sqti, gf, description);
-                peer.setKind(this.kind);
-                session.save(peer);
+                this.peer = new SedimentLoadLS(river, u, ti, sqti, gf, this.description);
+                this.peer.setKind(this.kind);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = loads.get(0);
+                this.peer = loads.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLSValue.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadLSValue.java	Sun Apr 08 18:07:06 2018 +0200
@@ -10,58 +10,60 @@
 
 import java.util.List;
 
-import org.hibernate.Session;
-import org.hibernate.Query;
-
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.SedimentLoadLS;
 import org.dive4elements.river.model.SedimentLoadLSValue;
+import org.hibernate.Query;
+import org.hibernate.Session;
 
 
 public class ImportSedimentLoadLSValue {
 
-    private Double station;
-    private Double value;
+    private final Double station;
+    private final Double value;
 
     private SedimentLoadLSValue peer;
 
 
-    public ImportSedimentLoadLSValue(Double station, Double value) {
+    public ImportSedimentLoadLSValue(final Double station, final Double value) {
         this.station = station;
         this.value   = value;
     }
 
 
-    public void storeDependencies(SedimentLoadLS sedimentLoadLS) {
-        getPeer(sedimentLoadLS);
+    public void storeDependencies(final SedimentLoadLS sedimentLoadLS, final StoreMode parentStoreMode) {
+        getPeer(sedimentLoadLS, parentStoreMode);
     }
 
 
-    public SedimentLoadLSValue getPeer(SedimentLoadLS sedimentLoadLS) {
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from SedimentLoadLSValue where " +
-                "   sedimentLoadLS=:sedimentLoadLS and " +
-                "   station=:station and " +
-                "   value=:value"
-            );
-
-            query.setParameter("sedimentLoadLS", sedimentLoadLS);
-            query.setParameter("station", station);
-            query.setParameter("value", value);
-
-            List<SedimentLoadLSValue> values = query.list();
-            if (values.isEmpty()) {
-                peer = new SedimentLoadLSValue(sedimentLoadLS, station, value);
-                session.save(peer);
+    public SedimentLoadLSValue getPeer(final SedimentLoadLS sedimentLoadLS, final StoreMode parentStoreMode) {
+        if (this.peer == null) {
+            List<SedimentLoadLSValue> values;
+            final Session session = ImporterSession.getInstance().getDatabaseSession();
+            if (parentStoreMode == StoreMode.INSERT)
+                values = null;
+            else {
+                final Query query = session.createQuery(
+                        "from SedimentLoadLSValue where " +
+                                "   sedimentLoadLS=:sedimentLoadLS and " +
+                                "   station=:station and " +
+                                "   value=:value"
+                        );
+                query.setParameter("sedimentLoadLS", sedimentLoadLS);
+                query.setParameter("station", this.station);
+                query.setParameter("value", this.value);
+                values = query.list();
+            }
+            if ((values == null) || values.isEmpty()) {
+                this.peer = new SedimentLoadLSValue(sedimentLoadLS, this.station, this.value);
+                session.save(this.peer);
             }
             else {
-                peer = values.get(0);
+                this.peer = values.get(0);
             }
         }
 
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadValue.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportSedimentLoadValue.java	Sun Apr 08 18:07:06 2018 +0200
@@ -10,6 +10,7 @@
 
 import java.util.List;
 
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.MeasurementStation;
 import org.dive4elements.river.model.SedimentLoad;
 import org.dive4elements.river.model.SedimentLoadValue;
@@ -27,43 +28,48 @@
     }
 
     public ImportSedimentLoadValue(
-        MeasurementStation station,
-        Double             value
-    ) {
+            final MeasurementStation station,
+            final Double             value
+            ) {
         this.station      = station;
         this.value        = value;
     }
 
-    protected SedimentLoadValue getPeer(SedimentLoad sedimentLoad) {
+    protected SedimentLoadValue getPeer(final SedimentLoad sedimentLoad, final StoreMode parentStoreMode) {
 
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from SedimentLoadValue where " +
-                "   measurementStation = :station and " +
-                "   sedimentLoad = :sedimentLoad and " +
-                "   value = :value");
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            List<SedimentLoadValue> values;
+            if (parentStoreMode == StoreMode.INSERT)
+                values = null;
+            else {
+                final Query query = session.createQuery(
+                        "from SedimentLoadValue where " +
+                                "   measurementStation = :station and " +
+                                "   sedimentLoad = :sedimentLoad and " +
+                        "   value = :value");
 
-            query.setParameter("station", station);
-            query.setParameter("sedimentLoad", sedimentLoad);
-            query.setParameter("value", value);
+                query.setParameter("station", this.station);
+                query.setParameter("sedimentLoad", sedimentLoad);
+                query.setParameter("value", this.value);
 
-            List<SedimentLoadValue> values = query.list();
-            if (values.isEmpty()) {
-                peer = new SedimentLoadValue(sedimentLoad, station, value);
-                session.save(peer);
+                values = query.list();
+            }
+            if ((values == null) || values.isEmpty()) {
+                this.peer = new SedimentLoadValue(sedimentLoad, this.station, this.value);
+                session.save(this.peer);
             }
             else {
-                peer = values.get(0);
+                this.peer = values.get(0);
             }
         }
 
-        return peer;
+        return this.peer;
     }
 
-    public void storeDependencies(SedimentLoad sedimentLoad) {
-        getPeer(sedimentLoad);
+    public void storeDependencies(final SedimentLoad sedimentLoad, final StoreMode parentStoreMode) {
+        getPeer(sedimentLoad, parentStoreMode);
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportWst.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportWst.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,16 +8,15 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.Wst;
-import org.dive4elements.river.model.River;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.apache.log4j.Logger;
-
-import org.hibernate.Session;
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.River;
+import org.dive4elements.river.model.Wst;
 import org.hibernate.Query;
-
-import java.util.ArrayList;
-import java.util.List;
+import org.hibernate.Session;
 
 /** Not (yet) db-mapped WST object. */
 public class ImportWst
@@ -29,12 +28,12 @@
     }
 
     public static final ImportWstColumnFactory COLUMN_FACTORY =
-        new ImportWstColumnFactory() {
-            @Override
-            public ImportWstColumn create(ImportWst importWst, int position) {
-                return new ImportWstColumn(importWst, null, null, position);
-            }
-        };
+            new ImportWstColumnFactory() {
+        @Override
+        public ImportWstColumn create(final ImportWst importWst, final int position) {
+            return new ImportWstColumn(importWst, null, null, position);
+        }
+    };
 
     protected String description;
 
@@ -48,6 +47,8 @@
 
     protected boolean kmUp;
 
+    protected StoreMode storeMode;
+
     /** Wst as in db. */
     protected Wst peer;
 
@@ -55,123 +56,126 @@
         this(COLUMN_FACTORY);
     }
 
-    public ImportWst(ImportWstColumnFactory columnFactory) {
+    public ImportWst(final ImportWstColumnFactory columnFactory) {
         this.columnFactory = columnFactory;
-        kind = 0;
-        columns = new ArrayList<ImportWstColumn>();
+        this.kind = 0;
+        this.columns = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
-    public ImportWst(String description) {
+    public ImportWst(final String description) {
         this(description, COLUMN_FACTORY);
     }
 
     public ImportWst(
-        String description,
-        ImportWstColumnFactory columnFactory
-    ) {
+            final String description,
+            final ImportWstColumnFactory columnFactory
+            ) {
         this(columnFactory);
         this.description = description;
     }
 
     public String getDescription() {
-        return description;
+        return this.description;
     }
 
     public Integer getKind() {
-        return kind;
+        return this.kind;
     }
 
-    public void setKind(Integer kind) {
+    public void setKind(final Integer kind) {
         this.kind = kind;
     }
 
     public boolean getKmUp() {
-        return kmUp;
+        return this.kmUp;
     }
 
-    public void setKmUp(boolean kmUp) {
+    public void setKmUp(final boolean kmUp) {
         this.kmUp = kmUp;
     }
 
-    public void setDescription(String description) {
+    public void setDescription(final String description) {
         this.description = description;
     }
 
     /** Create columns that can be accessed with getColumn. */
-    public void setNumberColumns(int numColumns) {
+    public void setNumberColumns(final int numColumns) {
         for (int i = 0; i < numColumns; ++i) {
-            columns.add(columnFactory.create(this, i));
+            this.columns.add(this.columnFactory.create(this, i));
         }
     }
 
     public int getNumberColumns() {
-        return columns.size();
+        return this.columns.size();
     }
 
-    public ImportWstColumn getColumn(int index) {
-        return columns.get(index);
+    public ImportWstColumn getColumn(final int index) {
+        return this.columns.get(index);
     }
 
     public List<ImportWstColumn> getColumns() {
-        return columns;
+        return this.columns;
     }
 
     /** Adds a column. Assumes that columns wst is this instance. */
-    public void addColumn(ImportWstColumn column) {
-        columns.add(column);
+    public void addColumn(final ImportWstColumn column) {
+        this.columns.add(column);
     }
 
     public ImportUnit getUnit() {
-        return unit;
+        return this.unit;
     }
 
-    public void setUnit(ImportUnit unit) {
+    public void setUnit(final ImportUnit unit) {
         this.unit = unit;
     }
 
-    public void storeDependencies(River river) {
+    public void storeDependencies(final River river) {
 
-        log.info("store '" + description + "'");
+        log.info("store '" + this.description + "'");
         getPeer(river);
 
-        for (ImportWstColumn column: columns) {
+        for (final ImportWstColumn column: this.columns) {
             column.storeDependencies(river);
         }
 
-        Session session = ImporterSession.getInstance().getDatabaseSession();
+        final Session session = ImporterSession.getInstance().getDatabaseSession();
         session.flush();
     }
 
     public boolean guessWaterLevelIncreasing() {
         int up = 0;
-        for (ImportWstColumn column: columns) {
+        for (final ImportWstColumn column: this.columns) {
             if (column.guessWaterLevelIncreasing()) ++up;
         }
-        return up > columns.size() - up;
+        return up > this.columns.size() - up;
     }
 
     /** Get corresponding mapped wst (from database). */
-    public Wst getPeer(River river) {
-        if (peer == null) {
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from Wst where " +
-                "river=:river and description=:description and kind=:kind");
+    public Wst getPeer(final River river) {
+        if (this.peer == null) {
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            final Query query = session.createQuery(
+                    "from Wst where " +
+                    "river=:river and description=:description and kind=:kind");
             query.setParameter("river",       river);
-            query.setParameter("description", description);
-            query.setParameter("kind",        kind);
-            List<Wst> wsts = query.list();
+            query.setParameter("description", this.description);
+            query.setParameter("kind",        this.kind);
+            final List<Wst> wsts = query.list();
             if (wsts.isEmpty()) {
-                peer = new Wst(river, description, kind);
-                session.save(peer);
+                this.peer = new Wst(river, this.description, this.kind);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = wsts.get(0);
+                this.peer = wsts.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
 
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportWstColumn.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportWstColumn.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,21 +8,19 @@
 
 package org.dive4elements.river.importer;
 
-import org.dive4elements.river.model.Wst;
-import org.dive4elements.river.model.WstColumn;
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+import org.apache.log4j.Logger;
+import org.dive4elements.river.importer.common.StoreMode;
 import org.dive4elements.river.model.River;
 import org.dive4elements.river.model.TimeInterval;
-
-import org.hibernate.Session;
+import org.dive4elements.river.model.Wst;
+import org.dive4elements.river.model.WstColumn;
 import org.hibernate.Query;
-
-import java.util.List;
-import java.util.ArrayList;
-import java.util.Random;
-
-import java.math.BigDecimal;
-
-import org.apache.log4j.Logger;
+import org.hibernate.Session;
 
 
 /** Unmapped column of a WST. */
@@ -41,20 +39,23 @@
     protected List<ImportWstColumnQRange> columnQRanges;
     protected List<ImportWstColumnValue>  columnValues;
 
+    protected StoreMode storeMode;
+
     protected WstColumn peer;
 
     public ImportWstColumn() {
-        columnQRanges = new ArrayList<ImportWstColumnQRange>();
-        columnValues  = new ArrayList<ImportWstColumnValue>();
+        this.columnQRanges = new ArrayList<>();
+        this.columnValues  = new ArrayList<>();
+        this.storeMode = StoreMode.NONE;
     }
 
     public ImportWstColumn(
-        ImportWst wst,
-        String    name,
-        String    description,
-        Integer   position,
-        String    source
-    ) {
+            final ImportWst wst,
+            final String    name,
+            final String    description,
+            final Integer   position,
+            final String    source
+            ) {
         this();
         this.wst         = wst;
         this.name        = name;
@@ -63,114 +64,114 @@
     }
 
     public ImportWstColumn(
-        ImportWst wst,
-        String    name,
-        String    description,
-        Integer   position
-    ) {
+            final ImportWst wst,
+            final String    name,
+            final String    description,
+            final Integer   position
+            ) {
         this(wst, name, description, position, null);
     }
 
     public ImportWst getWst() {
-        return wst;
+        return this.wst;
     }
 
-    public void setWst(ImportWst wst) {
+    public void setWst(final ImportWst wst) {
         this.wst = wst;
     }
 
     public String getName() {
-        return name;
+        return this.name;
     }
 
-    public void setName(String name) {
+    public void setName(final String name) {
         this.name = name;
     }
 
     public String getDescription() {
-        return description;
+        return this.description;
     }
 
-    public void setDescription(String description) {
+    public void setDescription(final String description) {
         this.description = description;
     }
 
     public Integer getPosition() {
-        return position;
+        return this.position;
     }
 
-    public void setPosition(Integer position) {
+    public void setPosition(final Integer position) {
         this.position = position;
     }
 
     public String getSource() {
-        return source;
+        return this.source;
     }
 
-    public void setSource(String source) {
+    public void setSource(final String source) {
         this.source = source;
     }
 
-    public void addColumnValue(BigDecimal position, BigDecimal w) {
-        columnValues.add(
-            new ImportWstColumnValue(this, position, w));
+    public void addColumnValue(final BigDecimal position, final BigDecimal w) {
+        this.columnValues.add(
+                new ImportWstColumnValue(this, position, w));
     }
 
-    public void addColumnQRange(ImportWstQRange columnQRange) {
-        columnQRanges.add(
-            new ImportWstColumnQRange(this, columnQRange));
+    public void addColumnQRange(final ImportWstQRange columnQRange) {
+        this.columnQRanges.add(
+                new ImportWstColumnQRange(this, columnQRange));
     }
 
 
     /** Get the Column Values stored in this column. */
     public List<ImportWstColumnValue> getColumnValues() {
-        return columnValues;
+        return this.columnValues;
     }
 
 
-    public void storeDependencies(River river) {
-        log.info("store column '" + name + "'");
+    public void storeDependencies(final River river) {
+        log.info("store column '" + this.name + "'");
         getPeer(river);
 
-        for (ImportWstColumnQRange columnQRange: columnQRanges) {
+        for (final ImportWstColumnQRange columnQRange: this.columnQRanges) {
             columnQRange.getPeer(river);
         }
 
-        for (ImportWstColumnValue columnValue: columnValues) {
+        for (final ImportWstColumnValue columnValue: this.columnValues) {
             columnValue.getPeer(river);
         }
     }
 
     public ImportTimeInterval getTimeInterval() {
-        return timeInterval;
+        return this.timeInterval;
     }
 
-    public void setTimeInterval(ImportTimeInterval timeInterval) {
+    public void setTimeInterval(final ImportTimeInterval timeInterval) {
         this.timeInterval = timeInterval;
     }
 
     public boolean guessWaterLevelIncreasing() {
 
-        int N = columnValues.size();
+        final int N = this.columnValues.size();
 
         if (N < 2) {
             return true;
         }
 
-        Random r = new Random();
+        final Random r = new Random();
         int up = 0;
 
-        int S = N < 50 ? N : (int)(0.1f * N)+1;
+        final int S = N < 50 ? N : (int)(0.1f * N)+1;
         for (int s = 0; s < S; ++s) {
             int i1, i2;
             do {
                 i1 = r.nextInt(N-1);
                 i2 = r.nextInt(N-1);
             } while (i1 == i2);
-            ImportWstColumnValue b = columnValues.get(i1);
-            ImportWstColumnValue a = columnValues.get(i2);
+            ImportWstColumnValue b = this.columnValues.get(i1);
+            ImportWstColumnValue a = this.columnValues.get(i2);
             if (b.getPosition().compareTo(a.getPosition()) < 0) {
-                ImportWstColumnValue t = a; a = b; b = t;
+                final ImportWstColumnValue t = a; a = b; b = t;
             }
 
             if (a.getW().compareTo(b.getW()) < 0) ++up;
@@ -180,37 +181,42 @@
     }
 
     /** Get corresponding mapped wst-column (from database). */
-    public WstColumn getPeer(River river) {
-        if (peer == null) {
-            Wst w = wst.getPeer(river);
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from WstColumn where" +
-                " wst=:wst and name=:name" +
-                " and source=:source" +
-                " and position=:position");
-            query.setParameter("wst",      w);
-            query.setParameter("name",     name);
-            query.setParameter("position", position);
-            query.setParameter("source",   source);
+    public WstColumn getPeer(final River river) {
+        if (this.peer == null) {
+            final Wst w = this.wst.getPeer(river);
+            List<WstColumn> columns;
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            if (this.wst.storeMode == StoreMode.INSERT)
+                columns = null;
+            else {
+                final Query query = session.createQuery(
+                        "from WstColumn where" +
+                                " wst=:wst and name=:name" +
+                                " and source=:source" +
+                        " and position=:position");
+                query.setParameter("wst",      w);
+                query.setParameter("name",     this.name);
+                query.setParameter("position", this.position);
+                query.setParameter("source",   this.source);
+                columns = query.list();
+            }
 
-            TimeInterval ti = timeInterval != null
-                ? timeInterval.getPeer()
-                : null;
+            final TimeInterval ti = (this.timeInterval != null) ? this.timeInterval.getPeer() : null;
 
-            List<WstColumn> columns = query.list();
-            if (columns.isEmpty()) {
-                log.debug("source: " + source);
-                peer = new WstColumn(
-                    w, name, description, source, position, ti);
-                session.save(peer);
+            if ((columns == null) || columns.isEmpty()) {
+                log.debug("source: " + this.source);
+                this.peer = new WstColumn(
+                        w, this.name, this.description, this.source, this.position, ti);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = columns.get(0);
+                this.peer = columns.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 
 }
--- a/backend/src/main/java/org/dive4elements/river/importer/ImportWstColumnQRange.java	Fri Apr 06 14:13:14 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/ImportWstColumnQRange.java	Sun Apr 08 18:07:06 2018 +0200
@@ -8,71 +8,81 @@
 
 package org.dive4elements.river.importer;
 
+import java.util.List;
+
+import org.dive4elements.river.importer.common.StoreMode;
+import org.dive4elements.river.model.River;
+import org.dive4elements.river.model.WstColumn;
 import org.dive4elements.river.model.WstColumnQRange;
 import org.dive4elements.river.model.WstQRange;
-import org.dive4elements.river.model.WstColumn;
-import org.dive4elements.river.model.River;
-
+import org.hibernate.Query;
 import org.hibernate.Session;
-import org.hibernate.Query;
-
-import java.util.List;
 
 public class ImportWstColumnQRange
 {
     protected ImportWstColumn wstColumn;
     protected ImportWstQRange qRange;
 
+    protected StoreMode storeMode;
+
     protected WstColumnQRange peer;
 
     public ImportWstColumnQRange() {
     }
 
     public ImportWstColumnQRange(
-        ImportWstColumn wstColumn,
-        ImportWstQRange qRange
-    ) {
+            final ImportWstColumn wstColumn,
+            final ImportWstQRange qRange
+            ) {
         this.wstColumn = wstColumn;
         this.qRange    = qRange;
+        this.storeMode = StoreMode.NONE;
     }
 
     public ImportWstColumn getWstColumn() {
-        return wstColumn;
+        return this.wstColumn;
     }
 
-    public void setWstColumn(ImportWstColumn wstColumn) {
+    public void setWstColumn(final ImportWstColumn wstColumn) {
         this.wstColumn = wstColumn;
     }
 
     public ImportWstQRange getQRange() {
-        return qRange;
+        return this.qRange;
     }
 
-    public void setQRange(ImportWstQRange qRange) {
+    public void setQRange(final ImportWstQRange qRange) {
         this.qRange = qRange;
     }
 
-    public WstColumnQRange getPeer(River river) {
-        if (peer == null) {
-            WstColumn c = wstColumn.getPeer(river);
-            WstQRange q = qRange.getPeer(river);
-            Session session = ImporterSession.getInstance()
-                .getDatabaseSession();
-            Query query = session.createQuery(
-                "from WstColumnQRange where " +
-                "wstColumn=:c and wstQRange=:q");
-            query.setParameter("c", c);
-            query.setParameter("q", q);
-            List<WstColumnQRange> cols = query.list();
-            if (cols.isEmpty()) {
-                peer = new WstColumnQRange(c, q);
-                session.save(peer);
+    public WstColumnQRange getPeer(final River river) {
+        if (this.peer == null) {
+            final WstColumn c = this.wstColumn.getPeer(river);
+            final WstQRange q = this.qRange.getPeer(river);
+            List<WstColumnQRange> cols;
+            final Session session = ImporterSession.getInstance()
+                    .getDatabaseSession();
+            if (this.wstColumn.storeMode == StoreMode.INSERT)
+                cols = null;
+            else {
+                final Query query = session.createQuery(
+                        "from WstColumnQRange where " +
+                        "wstColumn=:c and wstQRange=:q");
+                query.setParameter("c", c);
+                query.setParameter("q", q);
+                cols = query.list();
+            }
+            if ((cols == null) || cols.isEmpty()) {
+                this.peer = new WstColumnQRange(c, q);
+                session.save(this.peer);
+                this.storeMode = StoreMode.INSERT;
             }
             else {
-                peer = cols.get(0);
+                this.peer = cols.get(0);
+                this.storeMode = StoreMode.UPDATE;
             }
         }
-        return peer;
+        return this.peer;
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

http://dive4elements.wald.intevation.org