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When calculate_cond_selectivity_for_table() takes into account multi-
column selectivities from range access, it tries to take-into account
that selectivity for some columns may have been already taken into account.
For example, for range access on IDX1 using {kp1, kp2}, the selectivity
of restrictions on "kp2" might have already been taken into account
to some extent.
So, the code tries to "discount" that using rec_per_key[] estimates.
This seems to be wrong and unreliable: the "discounting" may produce a
rselectivity_multiplier number that hints that the overall selectivity
of range access on IDX1 was greater than 1.
Do a conservative fix: if we arrive at conclusion that selectivity of
range access on condition in IDX1 >1.0, clip it down to 1.
17 lines
514 B
Text
17 lines
514 B
Text
--source include/have_innodb.inc
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# This test is slow on buildbot.
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--source include/big_test.inc
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--source include/default_optimizer_switch.inc
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--source include/not_embedded.inc
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--source ./include/innodb_stable_estimates.inc
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SET SESSION STORAGE_ENGINE='InnoDB';
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set @save_optimizer_switch_for_selectivity_test=@@optimizer_switch;
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set optimizer_switch='extended_keys=on';
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--source selectivity_notembedded.test
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set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
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SET SESSION STORAGE_ENGINE=DEFAULT;
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