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More hints for getRange() on Oracle #2421
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For some unknown reason, Oracle picks a very inefficient plan sometimes: NESTED LOOPS +-VIEW | +-WINDOW NOSORT STOPKEY | +-SORT GROUP BY NOSORT | +-INDEX FULL SCAN `- INDEX FAST FULL SCAN Notice "FAST FULL SCAN" instead of "UNIQUE SCAN" or "RANGE SCAN". Basically, Oracle decides to scan the whole index on every iteration of the join loop, which is extremely slow. We add more hints to discourage this behavior.
berler
approved these changes
Oct 3, 2017
dxiao
approved these changes
Oct 4, 2017
Codecov Report
@@ Coverage Diff @@
## develop #2421 +/- ##
=============================================
+ Coverage 60.21% 60.26% +0.04%
- Complexity 4651 4652 +1
=============================================
Files 826 826
Lines 39052 39052
Branches 4014 4014
=============================================
+ Hits 23517 23534 +17
+ Misses 14058 14046 -12
+ Partials 1477 1472 -5
Continue to review full report at Codecov.
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hsaraogi
approved these changes
Oct 5, 2017
gbonik
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that referenced
this pull request
Oct 5, 2017
* More hints for getRange() on Oracle For some unknown reason, Oracle picks a very inefficient plan sometimes: NESTED LOOPS +-VIEW | +-WINDOW NOSORT STOPKEY | +-SORT GROUP BY NOSORT | +-INDEX FULL SCAN `- INDEX FAST FULL SCAN Notice "FAST FULL SCAN" instead of "UNIQUE SCAN" or "RANGE SCAN". Basically, Oracle decides to scan the whole index on every iteration of the join loop, which is extremely slow. We add more hints to discourage this behavior. * Release notes for #2421 (cherry picked from commit 8c0ad27)
gbonik
added a commit
that referenced
this pull request
Oct 5, 2017
* More hints for getRange() on Oracle For some unknown reason, Oracle picks a very inefficient plan sometimes: NESTED LOOPS +-VIEW | +-WINDOW NOSORT STOPKEY | +-SORT GROUP BY NOSORT | +-INDEX FULL SCAN `- INDEX FAST FULL SCAN Notice "FAST FULL SCAN" instead of "UNIQUE SCAN" or "RANGE SCAN". Basically, Oracle decides to scan the whole index on every iteration of the join loop, which is extremely slow. We add more hints to discourage this behavior. * Release notes for #2421 (cherry picked from commit 8c0ad27)
This was referenced Aug 30, 2022
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For some unknown reason, Oracle picks a very inefficient plan sometimes:
NESTED LOOPS
+-VIEW
| +-WINDOW NOSORT STOPKEY
| +-SORT GROUP BY NOSORT
| +-INDEX FULL SCAN
`- INDEX FAST FULL SCAN
Notice "FAST FULL SCAN" instead of "UNIQUE SCAN" or "RANGE SCAN".
Basically, Oracle decides to scan the whole index on every iteration
of the join loop, which is extremely slow.
We add more hints to discourage this behavior.
See PDS-56862
Priority (whenever / two weeks / yesterday):
High
This change is