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(parent: 09ff76f) | patch
Use fuzzy not exact cost comparison for the final tie-breaker in add_path.
authorTom Lane <tgl@sss.pgh.pa.us>
Sat, 21 Apr 2012 04:51:14 +0000 (00:51 -0400)
committerTom Lane <tgl@sss.pgh.pa.us>
Sat, 21 Apr 2012 04:51:14 +0000 (00:51 -0400)
commit33e99153e93b9accfa51ac036828144e1c2507b7
tree9d0d57a0ec28d5b47d7cea5c3e18df60a6f368a7tree | snapshot
parent09ff76fcdb275769ac4d1a45a67416735613d04bcommit | diff
Use fuzzy not exact cost comparison for the final tie-breaker in add_path.

Instead of an exact cost comparison, use a fuzzy comparison with 1e-10
delta after all other path metrics have proved equal.  This is to avoid
having platform-specific roundoff behaviors determine the choice when
two paths are really the same to our cost estimators.  Adjust the
recently-added test case that made it obvious we had a problem here.
src/backend/optimizer/util/pathnode.c diff | blob | history
src/test/regress/expected/join.out diff | blob | history
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