1. 24 4月, 2005 13 次提交
  2. 23 4月, 2005 2 次提交
  3. 22 4月, 2005 7 次提交
  4. 21 4月, 2005 3 次提交
    • B
      Updated text for bitmaps: · c6221db3
      Bruce Momjian 提交于
      <   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.
      c6221db3
    • B
      Done: · 631e0314
      Bruce Momjian 提交于
      < * Add tool to query pg_stat_* tables and report indexes that aren't needed
      <   or tables that might need indexes
      631e0314
    • T
      Add note clarifying that indexes that support ordered scans had better · 1c155c8d
      Tom Lane 提交于
      allow clauseless scans.
      1c155c8d
  5. 20 4月, 2005 3 次提交
    • B
      Add: · de4fbfad
      Bruce Momjian 提交于
      > * Add tool to query pg_stat_* tables and report indexes that aren't needed
      >   or tables that might need indexes
      de4fbfad
    • B
      Add: · e5c7c051
      Bruce Momjian 提交于
      > * Log queries where the optimizer row estimates were dramatically
      >   different from the number of rows actually found (?)
      e5c7c051
    • B
      Add: · 047b8a71
      Bruce Momjian 提交于
      > * All ability to monitor the use of temporary sort files
      047b8a71
  6. 19 4月, 2005 6 次提交
  7. 18 4月, 2005 6 次提交