From: | Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM> |
---|---|
To: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | [PATCH] Extending pg_class info + more flexible TOAST chunk size |
Date: | 2008-10-12 13:32:46 |
Message-ID: | 48F1FC7E.1060406@sun.com |
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Lists: | pgsql-hackers |
Bacause MAX_TOAST_CHUNK_SIZE is related on page layout version I need have toast
chunk size more flexible.
Attached patch add three new columns into pg_class
relblocksize - which is always BLCKSZ. I put it there for fullness, but i could
be use in future development to specify different BLCKSZ per relation.
relsegsize - currently it is always RELSEG_FILE. I performed basic adjustment in
smgr.c and md.c. Now only smgropen contains reference to RELSEG_FILE. The
problem how to do it fully dynamic is how to pass information rel_rd->relsegsize
down into smgropen. One idea is to extend relfilenode, but I'm not sure about it.
relmaxitemsize - it is set to TOAST_MAX_CHUNK_SIZE. Other relation has this
value set to zero for now. toast functions are fully aware about this setting
and use it. This column will be convert to int2vector during pg_upgrade
development (I need to track information for each page version).
Additional work could be add CRATE TABLE ... WITH chunksize=xxxx
Patch requires increase control file version and catalog version.
thanks for your comments
Zdenek
--
Zdenek Kotala Sun Microsystems
Prague, Czech Republic http://sun.com/postgresql
Attachment | Content-Type | Size |
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pg_class.patch.gz | application/x-gzip | 6.0 KB |
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