From 55af2a43372f0fe9da312b8db35874a18a226143 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Fri, 2 Sep 2005 00:49:57 +0000 Subject: Duplicate: < * Maintain a map of recently-expired rows < < This allows vacuum to target specific pages for possible free space < without requiring a sequential scan. < Update entry: > One complexity is that index entries still have to be vacuumed, and > doing this without an index scan (by using the heap values to find the > index entry) might be slow and unreliable, especially for user-defined > index functions. --- doc/src/FAQ/TODO.html | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'doc/src') diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index 734597a9648..f24c9a5605f 100644 --- a/doc/src/FAQ/TODO.html +++ b/doc/src/FAQ/TODO.html @@ -8,7 +8,7 @@

PostgreSQL TODO List

Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
-Last updated: Tue Aug 30 19:25:23 EDT 2005 +Last updated: Thu Sep 1 20:49:44 EDT 2005

The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html. @@ -730,10 +730,6 @@ first.

Moved tuples are invisible to other backends so they don't require a write lock. However, the read lock promotion to write lock could lead to deadlock situations. -

Maintain a map of recently-expired rows -

This allows vacuum to target specific pages for possible free space - without requiring a sequential scan.

Auto-fill the free space map by scanning the buffer cache or by checking pages written by the background writer @@ -742,6 +738,10 @@ first. writer or some other process record pages that have expired rows, then VACUUM can look at just those pages rather than the entire table. In the event of a system crash, the bitmap would probably be invalidated. + One complexity is that index entries still have to be vacuumed, and + doing this without an index scan (by using the heap values to find the + index entry) might be slow and unreliable, especially for user-defined + index functions.

%Add system view to show free space map contents

Auto-vacuum -- cgit v1.2.3