Updated text for bitmaps:

<   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.  They can index by tid or can be lossy requiring a scan of the
<   heap page to find matching rows, or perhaps use a mixed solution where
<   tids are recorded for pages with only a few matches and per-page bitmaps
<   are used for more dense pages.  Another idea is to use a 32-bit bitmap
<   for every page and set a bit based on the item number mod(32).

>   This feature allows separate indexes to be ANDed or ORed together.  This
>   is particularly useful for data warehousing applications that need to
>   query the database in an many permutations.  This feature scans an index
>   and creates an in-memory bitmap, and allows that bitmap to be combined
>   with other bitmap created in a similar way.  The bitmap can either index
>   all TIDs, or be lossy, meaning it records just page numbers and each
>   page tuple has to be checked for validity in a separate pass.

diff --git a/doc/TODO b/doc/TODO
index 9c28981a3b769596c10094b0865cf6981ceacb27..6e42de72b1c01c4b7315e45b8ad1e65550a4fd6a 100644 (file)
--- a/doc/TODO
+++ b/doc/TODO
@@ -2,7 +2,7 @@
 PostgreSQL TODO List
 ====================
 Current maintainer:    Bruce Momjian ([email protected])
-Last updated:      Thu Apr 21 00:09:27 EDT 2005
+Last updated:      Thu Apr 21 11:20:13 EDT 2005
 
 The most recent version of this document can be viewed at the PostgreSQL web
 site, http://www.PostgreSQL.org.
@@ -300,14 +300,13 @@ 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.  They can index by tid or can be lossy requiring a scan of the
-  heap page to find matching rows, or perhaps use a mixed solution where
-  tids are recorded for pages with only a few matches and per-page bitmaps
-  are used for more dense pages.  Another idea is to use a 32-bit bitmap
-  for every page and set a bit based on the item number mod(32).
+  This feature allows separate indexes to be ANDed or ORed together.  This
+  is particularly useful for data warehousing applications that need to
+  query the database in an many permutations.  This feature scans an index
+  and creates an in-memory bitmap, and allows that bitmap to be combined
+  with other bitmap created in a similar way.  The bitmap can either index
+  all TIDs, or be lossy, meaning it records just page numbers and each
+  page tuple has to be checked for validity in a separate pass.
 
 * Allow the creation of on-disk bitmap indexes which can be quickly
   combined with other bitmap indexes

diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html
index 70c1e25706923f8050927986660a8a6f31f4e5a2..725e7c312e3db32543a9b210a8f4b3352d223b3b 100644 (file)
--- a/doc/src/FAQ/TODO.html
+++ b/doc/src/FAQ/TODO.html
@@ -8,7 +8,7 @@
 
 PostgreSQL TODO List
 Current maintainer:     Bruce Momjian ([email protected])
-Last updated:           Thu Apr 21 00:09:27 EDT 2005
+Last updated:           Thu Apr 21 11:20:13 EDT 2005
 
 The most recent version of this document can be viewed at the PostgreSQL web
 site, http://www.PostgreSQL.org.
@@ -277,14 +277,13 @@ first.
   before accessing the heap rows.
 
   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.  They can index by tid or can be lossy requiring a scan of the
-  heap page to find matching rows, or perhaps use a mixed solution where
-  tids are recorded for pages with only a few matches and per-page bitmaps
-  are used for more dense pages.  Another idea is to use a 32-bit bitmap
-  for every page and set a bit based on the item number mod(32).
+  This feature allows separate indexes to be ANDed or ORed together.  This
+  is particularly useful for data warehousing applications that need to
+  query the database in an many permutations.  This feature scans an index
+  and creates an in-memory bitmap, and allows that bitmap to be combined
+  with other bitmap created in a similar way.  The bitmap can either index
+  all TIDs, or be lossy, meaning it records just page numbers and each
+  page tuple has to be checked for validity in a separate pass.
 
   Allow the creation of on-disk bitmap indexes which can be quickly
   combined with other bitmap indexes