Mercurial > dive4elements > gnv-client
diff geo-backend/ChangeLog @ 555:825781a39c70
Fixed gnv/issue107
geo-backend/trunk@632 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
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date | Tue, 26 Jan 2010 16:33:36 +0000 |
parents | 0ee3c0ed40e4 |
children | 48121fa4dc95 |
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--- a/geo-backend/ChangeLog Tue Jan 26 13:55:55 2010 +0000 +++ b/geo-backend/ChangeLog Tue Jan 26 16:33:36 2010 +0000 @@ -1,3 +1,25 @@ +2009-01-25 Sascha L. Teichmann <sascha.teichmann@intevation.de> + + Fix for gnv/issue107 + + * src/main/java/de/intevation/gnv/geobackend/util/RedundancyRemover.java: + New. Used to reduce the redundancy of data in SQL result sets. Column + values are very distinct so the degree or redundancy is very high. E.g + the SDE produces for each date value a java.util.GregorianCalendar object + which are very heavy weighted. We only use them r/o so we can hash each date + value to one unique representative. Same logic applys to integer values + and so on. + + With this technique we are able to reduce the memory consumption by + over 90%. Because it is not very feasible to store the whole history + of column we only have a limited number of cached values per column. + This is controlled via the system property + "de.intevation.gnv.geobackend.util.RedundancyRemover.lookback" which + defaults to 1029. + + * src/main/java/de/intevation/gnv/geobackend/sde/datasources/ArcSDEStatement.java: + Use RedundancyRemovers to filter the incoming traffic from SDE. + 2010-01-26 Tim Englich <tim.englich@intevation.de> * src/test/java/de/intevation/gnv/geobackend/base/query/ToCharSample.java :