diff options
| author | Bruce Momjian | 2004-11-04 16:19:46 +0000 |
|---|---|---|
| committer | Bruce Momjian | 2004-11-04 16:19:46 +0000 |
| commit | c894e7e8e06e88fc6d54081818b30f123a117dbd (patch) | |
| tree | 84a1ff7521683210b7ed623275af3febc62a513b | |
| parent | c874e7727a43990f48efe773b01087ee0b3fb374 (diff) | |
Update bitmap index entries:
< * Allow the creation of bitmap indexes which can be quickly combined
< with other bitmap indexes
> * Allow non-bitmap indexes to be combined by creating bitmaps in memory
259,261c258,259
< combined. Such indexes could be more compact if there are few unique
< value. Also, perhaps they can be lossy requiring a scan of the heap page
< to find matching rows.
> combined. They can index by tid or can be lossy requiring a scan of the
> heap page to find matching rows.
263c261,262
< * Allow non-bitmap indexes to be combined
> * Allow the creation of on-disk bitmap indexes which can be quickly
> combined with other bitmap indexes
265,266c264
< Do lookups on non-bitmap indexes and create bitmaps in memory that can be
< combined with other indexes.
> Such indexes could be more compact if there are few unique value.
| -rw-r--r-- | doc/TODO | 16 |
1 files changed, 7 insertions, 9 deletions
@@ -5,7 +5,7 @@ TODO list for PostgreSQL Bracketed items "[]" have more detail. Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) -Last updated: Wed Nov 3 22:57:53 EST 2004 +Last updated: Thu Nov 4 11:19:28 EST 2004 The most recent version of this document can be viewed at the PostgreSQL web site, http://www.PostgreSQL.org. @@ -250,20 +250,18 @@ Indexes order. Another method would be to sort heap ctids matching the index before accessing the heap rows. -* Allow the creation of bitmap indexes which can be quickly combined - with other bitmap indexes +* Allow non-bitmap indexes to be combined by creating bitmaps in memory Bitmap indexes index single columns that can be combined with other bitmap indexes to dynamically create a composite index to match a specific query. Each index is a bitmap, and the bitmaps are bitwise AND'ed or OR'ed to be - combined. Such indexes could be more compact if there are few unique - value. Also, perhaps they can be lossy requiring a scan of the heap page - to find matching rows. + combined. They can index by tid or can be lossy requiring a scan of the + heap page to find matching rows. -* Allow non-bitmap indexes to be combined +* Allow the creation of on-disk bitmap indexes which can be quickly + combined with other bitmap indexes - Do lookups on non-bitmap indexes and create bitmaps in memory that can be - combined with other indexes. + Such indexes could be more compact if there are few unique value. * Allow use of indexes to search for NULLs |