| From: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> |
|---|---|
| To: | PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org> |
| Subject: | Skip hole in log_newpage |
| Date: | 2013-12-03 11:03:41 |
| Message-ID: | 529DBA8D.3050405@vmware.com |
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| Lists: | pgsql-hackers |
The log_newpage function, used to WAL-log a full copy of a page, is
missing the trick we normally use for full-page images to leave out the
unused space on the block. That's pretty trivial to implement, so we should.
The place where this matters the most is when building a new B-tree
index. When wal_level > minimal, all pages in the created index are
logged with log_newpage, and by default we leave 10% free space on index
pages. So implementing this reduces the amount of WAL generated by index
creation by roughly 10%.
Anyone see a problem with this?
- Heikki
| Attachment | Content-Type | Size |
|---|---|---|
| log_newpage_hole-1.patch | text/x-diff | 15.1 KB |
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