From: Fred T. <fr...@us...> - 2014-08-06 19:34:00
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Obviously there is a calculation error. I think the total was being added to the previous total at checkpoints. The code in this area has been reviewed and improved since 2.3.2 and the next version should report a better approximation. Also note HSQLDB tables are copied completely when adding / removing indexes and making other changes to table structure. The space for the old copy is not recorded as lost space. Fred Toussi On Wed, Aug 6, 2014, at 18:20, xav...@st... wrote: > Hi, > > I'm embedding HSQLDB v2.3.2 in an application, and I'm trying to use the > FILE_LOST_BYTES column to determine the amount of wasted space and the > percentage of fragmentation of my cache file and trigger either a > CHECKPOINT DEFRAG or SHUTDOWN COMPACT on the embeded database during > application startup when above a configurable percentage or amount. > I'm doing this on application startup rather than using the "SET FILES > DEFRAG" statement to avoid the database going down for a relatively long > time (DB is a couple of GBs) at unpredictable moments while the > application is running. > > The issue I'm having is that I'm getting weird values in the > FILE_LOST_BYTES column after a day or two of mixed reads and > insert/update/delete activity. The values in this column grow very large > and above the actual .data file size, most of the time thousands of time > bigger than it, and very much above the capacity of the disk hosting the > database (600 TB...). > > For reference, the query I'm using: > SELECT CACHE_FILE, FILE_LOST_BYTES FROM > INFORMATION_SCHEMA.SYSTEM_CACHEINFO > > Is there something I'm missing ? Maybe the unit for the column isn't > BYTES as the column name implies, or is there something wrong with the > way this information is made available in the information schema ? > > Best regards, > > Xavier BRUGGHEMAN > > ------------------------------------------------------------------------------ > Infragistics Professional > Build stunning WinForms apps today! > Reboot your WinForms applications with our WinForms controls. > Build a bridge from your legacy apps to the future. > http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk > _______________________________________________ > Hsqldb-user mailing list > Hsq...@li... > https://lists.sourceforge.net/lists/listinfo/hsqldb-user |