From c894e7e8e06e88fc6d54081818b30f123a117dbd Mon Sep 17 00:00:00 2001 From: Bruce Momjian <bruce@momjian.us> Date: Thu, 4 Nov 2004 16:19:46 +0000 Subject: [PATCH] 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. --- doc/TODO | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/doc/TODO b/doc/TODO index 21a36a05818..853c4575829 100644 --- a/doc/TODO +++ b/doc/TODO @@ -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 -- GitLab