diff options
| author | Bruce Momjian <bruce@momjian.us> | 2007-08-15 15:53:30 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2007-08-15 15:53:30 +0000 |
| commit | 5ff95e6b8e19cef5e7fd15368194da1d29ebb0be (patch) | |
| tree | e22f901b0ad4ba71ce0147ef5cccd64977736c77 | |
| parent | 811f91cf5a94d1c467536fcafcaf82cd7e514276 (diff) | |
Add third idea about pulling data from indexes.
> A third idea would be for a heap scan to check if all rows are visible
> and if so set a per-table flag which can be checked by index scans.
> Any change to the table would have to clear the flag. To detect
> changes during the heap scan a counter could be set at the start and
> checked at the end --- if it is the same, the table has not been
> modified --- any table change would increment the counter.
| -rw-r--r-- | doc/src/FAQ/TODO.html | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index 076431b275c..35ee8b05934 100644 --- a/doc/src/FAQ/TODO.html +++ b/doc/src/FAQ/TODO.html @@ -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: Wed Aug 15 11:36:16 EDT 2007 +Last updated: Wed Aug 15 11:48:07 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>. @@ -1011,6 +1011,13 @@ first. There is also a developer's wiki at<br/> accessed bitmaps would have to be stored in shared memory. One 8k page of bitmaps could track 512MB of heap pages. </p> +<p> A third idea would be for a heap scan to check if all rows are visible + and if so set a per-table flag which can be checked by index scans. + Any change to the table would have to clear the flag. To detect + changes during the heap scan a counter could be set at the start and + checked at the end --- if it is the same, the table has not been + modified --- any table change would increment the counter. +</p> </li><li>Consider automatic caching of statements at various levels: <ul> <li>Parsed query tree |