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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
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<   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.
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Bruce Momjian 2004-11-04 16:19:46 +00:00
parent c874e7727a
commit c894e7e8e0
1 changed files with 7 additions and 9 deletions
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@ -5,7 +5,7 @@ TODO list for PostgreSQL
Bracketed items "[]" have more detail. Bracketed items "[]" have more detail.
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) 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 The most recent version of this document can be viewed at the PostgreSQL web
site, http://www.PostgreSQL.org. site, http://www.PostgreSQL.org.
@ -250,20 +250,18 @@ Indexes
order. Another method would be to sort heap ctids matching the index order. Another method would be to sort heap ctids matching the index
before accessing the heap rows. before accessing the heap rows.
* Allow the creation of bitmap indexes which can be quickly combined * Allow non-bitmap indexes to be combined by creating bitmaps in memory
with other bitmap indexes
Bitmap indexes index single columns that can be combined with other bitmap Bitmap indexes index single columns that can be combined with other bitmap
indexes to dynamically create a composite index to match a specific query. 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 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 combined. They can index by tid or can be lossy requiring a scan of the
value. Also, perhaps they can be lossy requiring a scan of the heap page heap page to find matching rows.
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 Such indexes could be more compact if there are few unique value.
combined with other indexes.
* Allow use of indexes to search for NULLs * Allow use of indexes to search for NULLs