diff options
author | Bruce Momjian | 2004-11-04 03:57:58 +0000 |
---|---|---|
committer | Bruce Momjian | 2004-11-04 03:57:58 +0000 |
commit | 4fbdfbffc64d3d5b64e6758d4795a8316636f1a1 (patch) | |
tree | 5a9a09950be9522032b858de7eb5a5466014f8d6 /contrib/mysql/mysql2pgsql | |
parent | c21214f1c0e4fb206d7286c6f0bf95fe94627527 (diff) |
Update:
< * Use bitmaps to combine existing indexes [performance]
> * Allow the creation of bitmap indexes which can be quickly combined
> with other bitmap indexes
255,257c256,266
< Bitmap indexes allow single indexed columns to be combined to
< dynamically create a composite index to match a specific query. Each
< index is a bitmap, and the bitmaps are AND'ed or OR'ed to be combined.
> 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.
>
> * Allow non-bitmap indexes to be combined
>
> Do lookups on non-bitmap indexes and create bitmaps in memory that can be
> combined with other indexes.
Diffstat (limited to 'contrib/mysql/mysql2pgsql')
0 files changed, 0 insertions, 0 deletions