sql: disable histogram usage for internal executor#104443
sql: disable histogram usage for internal executor#104443craig[bot] merged 1 commit intocockroachdb:masterfrom
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Since cockroachdb#101486, the internal executor has used global defaults for session settings. This effectively enabled `optimizer_use_histograms` for the internal executor, which was disabled before. This caused a huge performance regression. The root cause of the regression is not yet understood. This commit disables `optimizer_use_histograms` as a temporary solution for the performance regression. Informs cockroachdb#102954 Release note: None
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This change is |
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Here's the SQL QPS before and after this change on 
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rafiss
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thanks for tracking this down!
DrewKimball
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Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status:complete! 1 of 0 LGTMs obtained (waiting on @mgartner)
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TFTRs! bors r+ |
michae2
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Reviewed 1 of 1 files at r1, all commit messages.
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Do we want to backport this to v23.1? |
I don't think so. #101486 introduced the regression and that was not backported to v23.1, AFAICT. |
Since #101486, the internal executor has used global defaults for
session settings. This effectively enabled
optimizer_use_histogramsfor the internal executor, which was disabled before. This caused a
huge performance regression. The root cause of the regression is not yet
understood. This commit disables
optimizer_use_histogramsas atemporary solution for the performance regression.
Informs #102954
Epic: None
Release note: None