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642aa4366d
tell the optimizer that every TokuDB "clustering" index is the "covering" index in the MariaDB optimizer sense.
38 lines
1.1 KiB
Text
38 lines
1.1 KiB
Text
SET DEFAULT_STORAGE_ENGINE = 'tokudb';
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DROP TABLE IF EXISTS foo;
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create table foo (a int, b int, c int, primary key (a), key (b) clustering=yes);
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replace into foo values (1,10,100), (2,20,200), (1,10,1000);
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explain select * from foo;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE foo index NULL b 5 NULL 2 Using index
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select * from foo;
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a b c
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1 10 1000
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2 20 200
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explain select * from foo order by b desc;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE foo index NULL b 5 NULL 2 Using index
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select * from foo order by b desc;
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a b c
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2 20 200
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1 10 1000
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insert ignore into foo values (3,30,300), (1,10,1);
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Warnings:
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Warning 1062 Duplicate entry '1' for key 'PRIMARY'
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explain select * from foo;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE foo index NULL b 5 NULL 3 Using index
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select * from foo;
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a b c
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1 10 1000
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2 20 200
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3 30 300
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explain select * from foo order by b desc;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE foo index NULL b 5 NULL 3 Using index
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select * from foo order by b desc;
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a b c
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3 30 300
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2 20 200
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1 10 1000
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drop table foo;
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