This item was fixed in a different way, so has been removed:

<
< * Allow free-behind capability for large sequential scans to avoid
<   kernel cache spoiling
<
<   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 2007-12-12 06:59:56 +00:00
parent 1565888578
commit c7e8d0f392
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 Dec 7 12:52:05 EST 2007
Last updated: Wed Dec 12 01:59:39 EST 2007
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
@ -1069,14 +1069,6 @@ Fsync
Cache Usage
===========
* Allow free-behind capability for large sequential scans to avoid
kernel cache spoiling
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 Dec 7 12:52:05 EST 2007
Last updated: Wed Dec 12 01:59:39 EST 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>.
@ -947,14 +947,7 @@ first. There is also a developer's wiki at<br/>
<h1><a name="section_12">Cache Usage</a></h1>
<ul>
<li>Allow free-behind capability for large sequential scans to avoid
kernel cache spoiling
<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