@ -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 22:46:01 EDT 2007
Last updated: Sat Jun 2 07:27:46 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 > .
@ -971,7 +971,14 @@ first. There is also a developer's wiki at<br/>
< h1 > < a name = "section_14" > Cache Usage< / a > < / h1 >
< ul >
< li > Speed up COUNT(*)
< 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(*)
< 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