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727491b72a
This includes all test changes from "Changing all cost calculation to be given in milliseconds" and forwards. Some of the things that caused changes in the result files: - As part of fixing tests, I added 'echo' to some comments to be able to easier find out where things where wrong. - MATERIALIZED has now a higher cost compared to X than before. Because of this some MATERIALIZED types have changed to DEPENDEND SUBQUERY. - Some test cases that required MATERIALIZED to repeat a bug was changed by adding more rows to force MATERIALIZED to happen. - 'Filtered' in SHOW EXPLAIN has in many case changed from 100.00 to something smaller. This is because now filtered also takes into account the smallest possible ref access and filters, even if they where not used. Another reason for 'Filtered' being smaller is that we now also take into account implicit filtering done for subqueries using FIRSTMATCH. (main.subselect_no_exists_to_in) This is caluculated in best_access_path() and stored in records_out. - Table orders has changed because more accurate costs. - 'index' and 'ALL' for small tables has changed to use 'range' or 'ref' because of optimizer_scan_setup_cost. - index can be changed to 'range' as 'range' optimizer assumes we don't have to read the blocks from disk that range optimizer has already read. This can be confusing in the case where there is no obvious where clause but instead there is a hidden 'key_column > NULL' added by the optimizer. (main.subselect_no_exists_to_in) - Scan on primary clustered key does not report 'Using Index' anymore (It's a table scan, not an index scan). - For derived tables, the number of rows is now 100 instead of 2, which can be seen in EXPLAIN. - More tests have "Using index for group by" as the cost of this optimization is now more correct (lower). - A primary key could be preferred for a normal key, even if it would access more rows, as it's faster to do 1 lokoup and 3 'index_next' on a clustered primary key than one lookup trough a secondary. (main.stat_tables_innodb) Notes: - There was a 4.7% more calls to best_extension_by_limited_search() in the main.greedy_optimizer test. However examining the test results it looked that the plans where slightly better (eq_ref where more chained together) so I assume this is ok. - I have verified a few test cases where there was notable/unexpected changes in the plan and in all cases the new optimizer plans where faster. (main.greedy_optimizer and some others)
270 lines
9.1 KiB
Text
270 lines
9.1 KiB
Text
SET @@session.default_storage_engine = 'InnoDB';
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SET @save_stats_persistent=@@GLOBAL.innodb_stats_persistent;
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SET GLOBAL innodb_stats_persistent=0;
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create table t1 (a int,
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b int as (-a),
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c int as (-a) persistent,
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index (c));
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insert into t1 (a) values (2), (1), (1), (3), (NULL);
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create table t2 like t1;
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insert into t2 (a) values (1);
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create table t3 (a int primary key,
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b int as (-a),
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c int as (-a) persistent unique);
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insert into t3 (a) values (2),(1),(3),(5),(4),(7);
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# select_type=SIMPLE, type=system
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select * from t2;
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a b c
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1 -1 -1
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explain select * from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 1
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select * from t2 where c=-1;
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a b c
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1 -1 -1
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explain select * from t2 where c=-1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ref c c 5 const 1
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# select_type=SIMPLE, type=ALL
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select * from t1 where b=-1;
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a b c
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1 -1 -1
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1 -1 -1
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explain select * from t1 where b=-1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 5 Using where
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# select_type=SIMPLE, type=const
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select * from t3 where a=1;
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a b c
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1 -1 -1
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explain select * from t3 where a=1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 const PRIMARY PRIMARY 4 const 1
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# select_type=SIMPLE, type=range
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select * from t3 where c>=-1;
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a b c
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1 -1 -1
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explain select * from t3 where c>=-1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range c c 5 NULL 1 Using index condition
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# select_type=SIMPLE, type=ref
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select * from t1,t3 where t1.c=t3.c and t3.c=-1;
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a b c a b c
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1 -1 -1 1 -1 -1
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1 -1 -1 1 -1 -1
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explain select * from t1,t3 where t1.c=t3.c and t3.c=-1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 const c c 5 const 1
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1 SIMPLE t1 ref c c 5 const 2
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# select_type=PRIMARY, type=index,ALL
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select * from t1 where b in (select c from t3);
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a b c
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2 -2 -2
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1 -1 -1
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1 -1 -1
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3 -3 -3
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explain select * from t1 where b in (select c from t3);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 5 Using where
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1 PRIMARY t3 eq_ref c c 5 test.t1.b 1 Using index
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# select_type=PRIMARY, type=range,ref
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select * from t1 where c in (select c from t3 where c between -2 and -1);
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a b c
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2 -2 -2
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1 -1 -1
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1 -1 -1
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explain select * from t1 where c in (select c from t3 where c between -2 and -1);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t3 range c c 5 NULL 2 Using where; Using index
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1 PRIMARY t1 ref c c 5 test.t3.c 1
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# select_type=UNION, type=system
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# select_type=UNION RESULT, type=<union1,2>
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select * from t1 union select * from t2;
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a b c
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2 -2 -2
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1 -1 -1
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3 -3 -3
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NULL NULL NULL
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explain select * from t1 union select * from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 5
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2 UNION t2 ALL NULL NULL NULL NULL 1
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NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
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# select_type=DERIVED, type=system
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set @tmp_optimizer_switch=@@optimizer_switch;
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set optimizer_switch='derived_merge=off,derived_with_keys=off';
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select * from (select a,b,c from t1) as t11;
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a b c
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2 -2 -2
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1 -1 -1
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1 -1 -1
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3 -3 -3
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NULL NULL NULL
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explain select * from (select a,b,c from t1) as t11;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY <derived2> ALL NULL NULL NULL NULL 5
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2 DERIVED t1 ALL NULL NULL NULL NULL 5
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set optimizer_switch=@tmp_optimizer_switch;
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###
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### Using aggregate functions with/without DISTINCT
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###
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# SELECT COUNT(*) FROM tbl_name
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select count(*) from t1;
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count(*)
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5
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explain select count(*) from t1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 index NULL c 5 NULL 5 Using index
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# SELECT COUNT(DISTINCT <non-vcol>) FROM tbl_name
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select count(distinct a) from t1;
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count(distinct a)
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3
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explain select count(distinct a) from t1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 5
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# SELECT COUNT(DISTINCT <non-stored vcol>) FROM tbl_name
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select count(distinct b) from t1;
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count(distinct b)
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3
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explain select count(distinct b) from t1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 5
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# SELECT COUNT(DISTINCT <stored vcol>) FROM tbl_name
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select count(distinct c) from t1;
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count(distinct c)
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3
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explain select count(distinct c) from t1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 range NULL c 5 NULL 5 Using index for group-by
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###
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### filesort & range-based utils
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###
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# SELECT * FROM tbl_name WHERE <vcol expr>
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select * from t3 where c >= -2;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where c >= -2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range c c 5 NULL 2 Using index condition
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# SELECT * FROM tbl_name WHERE <non-vcol expr>
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select * from t3 where a between 1 and 2;
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a b c
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1 -1 -1
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2 -2 -2
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explain select * from t3 where a between 1 and 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range PRIMARY PRIMARY 4 NULL 2 Using where
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# SELECT * FROM tbl_name WHERE <non-indexed vcol expr>
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select * from t3 where b between -2 and -1;
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a b c
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1 -1 -1
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2 -2 -2
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explain select * from t3 where b between -2 and -1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 ALL NULL NULL NULL NULL 6 Using where
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# SELECT * FROM tbl_name WHERE <indexed vcol expr>
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select * from t3 where c between -2 and -1;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where c between -2 and -1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range c c 5 NULL 2 Using index condition
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# SELECT * FROM tbl_name WHERE <non-vcol expr> ORDER BY <non-indexed vcol>
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select * from t3 where a between 1 and 2 order by b;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where a between 1 and 2 order by b;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range PRIMARY PRIMARY 4 NULL 2 Using where; Using filesort
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# SELECT * FROM tbl_name WHERE <non-vcol expr> ORDER BY <indexed vcol>
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select * from t3 where a between 1 and 2 order by c;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where a between 1 and 2 order by c;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range PRIMARY PRIMARY 4 NULL 2 Using where; Using filesort
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# SELECT * FROM tbl_name WHERE <non-indexed vcol expr> ORDER BY <non-vcol>
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select * from t3 where b between -2 and -1 order by a;
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a b c
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1 -1 -1
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2 -2 -2
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explain select * from t3 where b between -2 and -1 order by a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 index NULL PRIMARY 4 NULL 6 Using where
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# SELECT * FROM tbl_name WHERE <non-indexed vcol expr> ORDER BY <non-indexed vcol>
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select * from t3 where b between -2 and -1 order by b;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where b between -2 and -1 order by b;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 ALL NULL NULL NULL NULL 6 Using where; Using filesort
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# SELECT * FROM tbl_name WHERE <indexed vcol expr> ORDER BY <non-indexed vcol>
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select * from t3 where c between -2 and -1 order by b;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where c between -2 and -1 order by b;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range c c 5 NULL 2 Using index condition; Using filesort
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# SELECT * FROM tbl_name WHERE <non-indexed vcol expr> ORDER BY <indexed vcol>
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select * from t3 where b between -2 and -1 order by c;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where b between -2 and -1 order by c;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 ALL NULL NULL NULL NULL 6 Using where; Using filesort
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# SELECT * FROM tbl_name WHERE <indexed vcol expr> ORDER BY <indexed vcol>
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select * from t3 where c between -2 and -1 order by c;
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a b c
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2 -2 -2
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1 -1 -1
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explain select * from t3 where c between -2 and -1 order by c;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t3 range c c 5 NULL 2 Using index condition
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# SELECT sum(<non-indexed vcol>) FROM tbl_name GROUP BY <non-indexed vcol>
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select sum(b) from t1 group by b;
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sum(b)
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NULL
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-3
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-2
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-2
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explain select sum(b) from t1 group by b;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 5 Using temporary; Using filesort
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# SELECT sum(<indexed vcol>) FROM tbl_name GROUP BY <indexed vcol>
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select sum(c) from t1 group by c;
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sum(c)
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NULL
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-3
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-2
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-2
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explain select sum(c) from t1 group by c;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 index NULL c 5 NULL 5 Using index
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# SELECT sum(<non-indexed vcol>) FROM tbl_name GROUP BY <indexed vcol>
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select sum(b) from t1 group by c;
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sum(b)
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NULL
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-3
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-2
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-2
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explain select sum(b) from t1 group by c;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 index NULL c 5 NULL 5
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# SELECT sum(<indexed vcol>) FROM tbl_name GROUP BY <non-indexed vcol>
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select sum(c) from t1 group by b;
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sum(c)
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NULL
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-3
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-2
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-2
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explain select sum(c) from t1 group by b;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 5 Using temporary; Using filesort
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SET GLOBAL innodb_stats_persistent=@save_stats_persistent;
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