This is a patch for TODO item: | Create a bitmap of pages that need vacuuming
Dead Space Map allows VACUUM to scan only pages that need vacuuming. I sent to HACKERS the description of this patch. Comments, suggestions and evaluation reports are welcome. Usage of the feature is below: - VACUUM FREEZE is recommended. Pages that need vacuuming and freezing are not separated in the patch. If we do non-FREEZE VACUUM, next VACUUM will also read pages that we cannot freeze all of tuples in it at the last VACUUM. It's a waste. - [GUC] dsm_buffers (integer) The used memory size in dead space map. Default is 16MB, that can track maximum 1TB of heap tables. - [GUC] dsm_vacuum (boolean) This enables the dead space map in VACUUM. Default is on. Even if it is off, DSM are always recorded and updated. - contrib/pg_deadspacemap This shows the contents of dead space map. See also README.pg_deadspacemap. Regards, --- ITAGAKI Takahiro NTT Open Source Software Center
deadspacemap.patch.gz
Description: Binary data
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