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mirror of https://github.com/postgres/postgres.git synced 2025-11-12 05:01:15 +03:00

Make source code READMEs more consistent. Add CVS tags to all README files.

This commit is contained in:
Bruce Momjian
2008-03-20 17:55:15 +00:00
parent 27dfc11d67
commit 4e228447aa
22 changed files with 148 additions and 93 deletions

View File

@@ -1,6 +1,6 @@
$PostgreSQL: pgsql/src/backend/storage/buffer/README,v 1.12 2007/05/30 20:11:58 tgl Exp $
$PostgreSQL: pgsql/src/backend/storage/buffer/README,v 1.13 2008/03/20 17:55:15 momjian Exp $
Notes about shared buffer access rules
Notes About Shared Buffer Access Rules
--------------------------------------
There are two separate access control mechanisms for shared disk buffers:
@@ -92,7 +92,7 @@ for VACUUM's use, since we don't allow multiple VACUUMs concurrently on a
single relation anyway.
Buffer manager's internal locking
Buffer Manager's Internal Locking
---------------------------------
Before PostgreSQL 8.1, all operations of the shared buffer manager itself
@@ -152,7 +152,7 @@ we could use per-backend LWLocks instead (a buffer header would then contain
a field to show which backend is doing its I/O).
Normal buffer replacement strategy
Normal Buffer Replacement Strategy
----------------------------------
There is a "free list" of buffers that are prime candidates for replacement.
@@ -201,7 +201,7 @@ have to give up and try another buffer. This however is not a concern
of the basic select-a-victim-buffer algorithm.)
Buffer ring replacement strategy
Buffer Ring Replacement Strategy
---------------------------------
When running a query that needs to access a large number of pages just once,
@@ -236,7 +236,7 @@ buffer, resulting in excessive WAL flushing. Allowing VACUUM to update
256KB between WAL flushes should be more efficient.
Background writer's processing
Background Writer's Processing
------------------------------
The background writer is designed to write out pages that are likely to be