Re: [PATCHES] Full page writes improvement, code update
Simon; Tom; Koichi is writing. Your question is how to determine WAL record generated between pg_start_backup and pg_stop_backup and here's an answer. XLogInsert( ) already has a logic to determine if inserting WAL record is between pg_start_backup and pg_stop_backup. Currently it is used to remove full_page_writes when full_page_writes=off. We can use this to mark WAL records. We have one bit not used in WAL record header, the last bit of xl_info, where upper four bits are used to indicate the resource manager and three of the rest are used to indicate number of full page writes included in the record. So in my proposal, this unused bit is used to mark that full page writes must not be removed at offline optimization by pg_complesslog. Sorry I didn't have mailing list capability from home and have just completed my subscription from home. I had to create new thread to continue my post. Sorry for confusion. Please refer to the original thread about this discussion. Best Regards; -- -- Koichi Suzuki ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
[PATCHES] Full page writes improvement, code update
Hi, Here's an update of a code to improve full page writes as proposed in http://archives.postgresql.org/pgsql-hackers/2007-01/msg01491.php and http://archives.postgresql.org/pgsql-patches/2007-01/msg00607.php Update includes some modification for error handling in archiver and restoration command. In the previous threads, I posted several evaluation and shown that we can keep all the full page writes needed for full XLOG crash recovery, while compressing archive log size considerably better than gzip, with less CPU consumption. I've found no further objection for this proposal but still would like to hear comments/opinions/advices. Regards; -- Koichi Suzuki pg_lesslog.tgz Description: Binary data ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org