diff options
| author | Bruce Momjian <bruce@momjian.us> | 2005-12-01 22:30:43 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2005-12-01 22:30:43 +0000 |
| commit | 113ece8f3d704cdcf20f2865d1ea8964159ee476 (patch) | |
| tree | 2e2725c25873bba26c29fc33274c464c74176762 | |
| parent | 915fb7f687bd6553ec6466776f6eb1d6b81fbfcc (diff) | |
| download | postgresql-113ece8f3d704cdcf20f2865d1ea8964159ee476.tar.gz postgresql-113ece8f3d704cdcf20f2865d1ea8964159ee476.zip | |
Add all heap page rows visible bitmap idea:
< the heap. One way to allow this is to set a bit to index tuples
> the heap. One way to allow this is to set a bit on index tuples
< be cleared when a heap tuple is expired.
<
> be cleared when a heap tuple is expired. Another idea is to maintain
> a bitmap of heap pages where all rows are visible to all backends,
> and allow index lookups to reference that bitmap to avoid heap
> lookups, perhaps the same bitmap we might add someday to determine
> which heap pages need vacuuming.
| -rw-r--r-- | doc/TODO | 11 | ||||
| -rw-r--r-- | doc/src/FAQ/TODO.html | 10 |
2 files changed, 14 insertions, 7 deletions
@@ -2,7 +2,7 @@ PostgreSQL TODO List ==================== Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) -Last updated: Thu Dec 1 17:12:27 EST 2005 +Last updated: Thu Dec 1 17:30:23 EST 2005 The most recent version of this document can be viewed at http://www.postgresql.org/docs/faqs.TODO.html. @@ -859,11 +859,14 @@ Cache Usage Currently indexes do not have enough tuple visibility information to allow data to be pulled from the index without also accessing - the heap. One way to allow this is to set a bit to index tuples + the heap. One way to allow this is to set a bit on index tuples to indicate if a tuple is currently visible to all transactions when the first valid heap lookup happens. This bit would have to - be cleared when a heap tuple is expired. - + be cleared when a heap tuple is expired. Another idea is to maintain + a bitmap of heap pages where all rows are visible to all backends, + and allow index lookups to reference that bitmap to avoid heap + lookups, perhaps the same bitmap we might add someday to determine + which heap pages need vacuuming. * Consider automatic caching of queries at various levels: diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index 7bb7cd28420..7e4961eaa7b 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:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</a>)<br/> -Last updated: Thu Dec 1 17:12:27 EST 2005 +Last updated: Thu Dec 1 17:30:23 EST 2005 </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>. @@ -778,10 +778,14 @@ first. </li><li>Allow data to be pulled directly from indexes <p> Currently indexes do not have enough tuple visibility information to allow data to be pulled from the index without also accessing - the heap. One way to allow this is to set a bit to index tuples + the heap. One way to allow this is to set a bit on index tuples to indicate if a tuple is currently visible to all transactions when the first valid heap lookup happens. This bit would have to - be cleared when a heap tuple is expired. + be cleared when a heap tuple is expired. Another idea is to maintain + a bitmap of heap pages where all rows are visible to all backends, + and allow index lookups to reference that bitmap to avoid heap + lookups, perhaps the same bitmap we might add someday to determine + which heap pages need vacuuming. </p> </li><li>Consider automatic caching of queries at various levels: <ul> |