1. 23 1月, 2005 1 次提交
    • B
      Update count(*) discussion ideas: · b60a8512
      Bruce Momjian 提交于
      <   BY col {DESC} LIMIT 1. Completing this item involves making this
      >   BY col {DESC} LIMIT 1. Completing this item involves doing this
      <   invalidated if anyone modifies the table.
      <
      >   invalidated if anyone modifies the table.  Another idea is to
      >   get a count directly from a unique index, but for this to be
      >   faster than a sequential scan it must avoid access to the heap
      >   to obtain tuple visibility information.
      >
      > * Allow data to be pulled directly from indexes
      >
      >   Currently indexes do not have enough tuple tuple visibility
      >   information to allow data to be pulled from the index without
      >   also accessing the heap.  One way to allow this is to set a bit
      >   to index tuples to indicate if a tuple is currently visible to
      >   all transactions when the first valid heap lookup happens.  This
      >   bit would have to be cleared when a heap tuple is expired.
      >
      b60a8512
  2. 22 1月, 2005 1 次提交
  3. 21 1月, 2005 1 次提交
  4. 20 1月, 2005 2 次提交
  5. 19 1月, 2005 5 次提交
    • B
      Add: · 0d19d8b8
      Bruce Momjian 提交于
      > * Add 'tid != tid ' operator for use in corruption recovery
      0d19d8b8
    • N
      d600c1db
    • B
      Fix typo. · 3fc86c0f
      Bruce Momjian 提交于
      3fc86c0f
    • N
      This patch makes some improvements to the rtree index implementation: · b4297c17
      Neil Conway 提交于
      (1) Keep a pin on the scan's current buffer and mark buffer. This
      avoids the need to do a ReadBuffer() for each tuple produced by the
      scan. Since ReadBuffer() is expensive, this is a significant win.
      
      (2) Convert a ReleaseBuffer(); ReadBuffer() pair into
      ReleaseAndReadBuffer(). Surely not a huge win, but it saves a lock
      acquire/release...
      
      (3) Remove a bunch of duplicated code in rtget.c; make rtnext() handle
      both the "initial result" and "subsequent result" cases.
      
      (4) Add support for index tuple killing
      
      (5) Remove rtscancache(): it is dead code, for the same reason that
      gistscancache() is dead code (an index scan ought not be invoked with
      NoMovementScanDirection).
      
      The end result is about a 10% improvement in rtree index scan perf,
      according to contrib/rtree_gist/bench.
      b4297c17
    • N
      Replace the use of "0" with "NULL" where appropriate in dllist.c, for · 1f5299bc
      Neil Conway 提交于
      good style and to satisfy sparse. From Alvaro Herrera.
      1f5299bc
  6. 18 1月, 2005 8 次提交
  7. 17 1月, 2005 15 次提交
  8. 16 1月, 2005 4 次提交
  9. 15 1月, 2005 3 次提交