TODO item not needed anymore now that the buffer cache is

scan-resistant:

<
< * Allow free-behind capability for large sequential scans, perhaps using
<   posix_fadvise()
<
<   Posix_fadvise() can control both sequential/random file caching and
<   free-behind behavior, but it is unclear how the setting affects other
<   backends that also have the file open, and the feature is not supported
<   on all operating systems.
This commit is contained in:
Bruce Momjian 2007-06-02 02:46:38 +00:00
parent 15f8202c20
commit ededa6dfc8
2 changed files with 3 additions and 18 deletions

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@ -1,7 +1,7 @@
PostgreSQL TODO List
====================
Current maintainer: Bruce Momjian (bruce@momjian.us)
Last updated: Fri Jun 1 14:41:49 EDT 2007
Last updated: Fri Jun 1 22:46:01 EDT 2007
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
@ -1090,14 +1090,6 @@ Fsync
Cache Usage
===========
* Allow free-behind capability for large sequential scans, perhaps using
posix_fadvise()
Posix_fadvise() can control both sequential/random file caching and
free-behind behavior, but it is unclear how the setting affects other
backends that also have the file open, and the feature is not supported
on all operating systems.
* Speed up COUNT(*)
We could use a fixed row count and a +/- count to follow MVCC

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@ -8,7 +8,7 @@
<body bgcolor="#FFFFFF" text="#000000" link="#FF0000" vlink="#A00000" alink="#0000FF">
<h1><a name="section_1">PostgreSQL TODO List</a></h1>
<p>Current maintainer: Bruce Momjian (<a href="mailto:bruce@momjian.us">bruce@momjian.us</a>)<br/>
Last updated: Fri Jun 1 14:41:49 EDT 2007
Last updated: Fri Jun 1 22:46:01 EDT 2007
</p>
<p>The most recent version of this document can be viewed at<br/>
<a href="http://www.postgresql.org/docs/faqs.TODO.html">http://www.postgresql.org/docs/faqs.TODO.html</a>.
@ -971,14 +971,7 @@ first. There is also a developer's wiki at<br/>
<h1><a name="section_14">Cache Usage</a></h1>
<ul>
<li>Allow free-behind capability for large sequential scans, perhaps using
posix_fadvise()
<p> Posix_fadvise() can control both sequential/random file caching and
free-behind behavior, but it is unclear how the setting affects other
backends that also have the file open, and the feature is not supported
on all operating systems.
</p>
</li><li>Speed up COUNT(*)
<li>Speed up COUNT(*)
<p> We could use a fixed row count and a +/- count to follow MVCC
visibility rules, or a single cached value could be used and
invalidated if anyone modifies the table. Another idea is to