This is a discussion on Row compression with range partitioned table within the DB2 forums, part of the Database Server Software category; --> Greetings! I have a table which is range-partitioned by a date column (one year per table-partition). Currently there are ...
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| Greetings! I have a table which is range-partitioned by a date column (one year per table-partition). Currently there are five table partitions (second number is the number of rows per table-partition): TAB_2006 338333 TAB_2007 127239 TAB_2008 174718 TAB_2009 1 TAB_2010 0 so, they all contain records except the last partition which is currently empty (and will be empty for some time...). The table itself was created with the option "COMPRESS YES", along with all partitions, and then the data was loaded into the table. No table-partitions were added (attached) afterwards. When I try the command: db2 reorg table [partitioned-table] resetdictionary; I get the warning message: SQL2220W The compression dictionary was not built for one or more data objects. The db2.nfy shows the following: ADM5591W A compression dictionary could not be built for object "6" in tablespace "5" because no eligible data was found. If a dictionary existed a-priori it will be used instead. The statistics for the table show that there is no compression at all in the table: AVGROWSIZE AVGCOMPRESSEDROWSIZE PCTPAGESSAVED AVGROWCOMPRESSIONRATIO PCTROWSCOMPRESSED ---------- -------------------- ------------- ------------------------ ------------------------ 612 0 0 +0,00000E+000 +0,00000E+000 What could be the problem here, why does the row compression not work? Because of the empty table partition? Because I don't read the table stats the right way? Any ideas? Regards, Damir |
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| Damir, I don't think you have an issue here. What you got was a warning, not an error. It looks like you got compressions for 2006-2008. Note that in DB2 9.5 the remaining partitions will automatically be compressed once sufficient data becomes available. Cheers Serge -- Serge Rielau DB2 Solutions Development IBM Toronto Lab |
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| Serge, thank you for the quick answer - the compression really did take place after the reorg, I just failed to run the runstats :-) So, after refreshing the stats the compression values indeed look very good for the table: AVGROWSIZE AVGCOMPRESSEDROWSIZE PCTPAGESSAVED AVGROWCOMPRESSIONRATIO PCTROWSCOMPRESSED ---------- -------------------- ------------- ------------------------ ------------------------ 173 173 71 +3,53826E+000 +1,00000E+002 Regards, Damir "Serge Rielau" <srielau@ca.ibm.com> wrote in message news:62tcchF258nhsU1@mid.individual.net... > Damir, > > I don't think you have an issue here. > What you got was a warning, not an error. It looks like you got > compressions for 2006-2008. > Note that in DB2 9.5 the remaining partitions will automatically be > compressed once sufficient data becomes available. > > Cheers > Serge > -- > Serge Rielau > DB2 Solutions Development > IBM Toronto Lab |
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