Extents management

Posted in 2000

Topics: Storage & Space Management, Migration, Import/Export & Data Conversion

Marcel Nihon — Fri, 27 Oct 2000 12:30:36 GMT — source: Informix-list mailing list archive (1991-1998)

Hi, Does someboby knows if it is legitim to eliminate interleaved extents in the SMI tables as we do in the user tables? To eliminate these extents in a user table, we reorganize with UNLOAD table, DROP table, change PRIMARY EXTENT and NEXT SIZE, LOAD table. Can we do that on SMI tables, for example sysprocbody, sysprocplan, ...? Thanks in advance,

↪ replying to Marcel Nihon

Art S. Kagel — Mon, 06 Nov 2000 19:14:42 -0500 — source: Informix-list mailing list archive (1991-1998)

NO! The SMI tables are NOT tables, they are pseudo-tables and are really just windows in to the engines disk and shared memory structures. NO NOT MUCK WITH THEM. On the other hand if you mean the system catalog tables, like the ones you mention, which are existent in every database, then you don't need to mess with them. Fragmentation and interleaving of extents in the system catalog has NOT EFFECT ON PERFORMANCE in an IDS server due to the Data Dictionary cache. If you have a HUGE number of tables you can adjust the size of the dictionary cache using the DD_HASHMAX and DD_HASHSIZE onconfig parameters. Art S. Kagel Marcel Nihon wrote: > > Hi, > Does someboby knows if it is legitim to eliminate interleaved extents in > the SMI tables as we do in the user tables? > To eliminate these extents in a user table, we reorganize with > UNLOAD table, DROP table, change PRIMARY EXTENT and NEXT SIZE, LOAD > table. > Can we do that on SMI tables, for example sysprocbody, sysprocplan, ...? > Thanks in advance,