mirror of
https://github.com/MariaDB/server.git
synced 2025-11-09 11:41:36 +03:00
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)
258 lines
5.5 KiB
Plaintext
258 lines
5.5 KiB
Plaintext
create temporary table t1 (i int) engine = innodb;
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insert into t1 values (1), (2), (3), (4);
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select * from t1;
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i
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1
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2
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3
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4
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select * from t1 where i = 4;
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i
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4
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drop table t1;
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create temporary table t1 (i int) engine = innodb;
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insert into t1 values (1), (2), (3), (4);
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select * from t1;
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i
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1
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2
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3
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4
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select * from t1 where i = 4;
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i
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4
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drop table t1;
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create temporary table t2 (i int) engine = innodb;
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insert into t2 values (1), (2), (3), (4);
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select * from t2;
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i
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1
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2
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3
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4
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select * from t2 where i = 4;
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i
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4
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drop table t2;
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create temporary table t1
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(keyc int, c1 char(100), c2 char(100),
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primary key(keyc)) engine = innodb;
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create procedure populate_t1()
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begin
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declare i int default 1;
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while (i <= 200) DO
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insert into t1 values (i, 'a', 'b');
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set i = i + 1;
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end while;
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end|
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set autocommit=0;
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select count(*) from t1;
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count(*)
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0
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call populate_t1();
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select count(*) from t1;
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count(*)
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200
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select * from t1 limit 10;
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keyc c1 c2
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1 a b
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2 a b
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3 a b
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4 a b
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5 a b
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6 a b
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7 a b
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8 a b
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9 a b
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10 a b
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set autocommit=1;
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truncate table t1;
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select count(*) from t1;
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count(*)
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0
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drop table t1;
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create temporary table t1 (i int) engine = innodb;
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insert into t1 values (1), (2), (3), (4);
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select * from t1;
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i
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1
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2
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3
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4
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select * from t1 where i = 4;
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i
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4
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drop table t1;
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create temporary table t1
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(keyc int, c1 char(100), c2 char(100),
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primary key(keyc))
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engine = innodb;
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begin;
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select count(*) from t1;
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count(*)
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0
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call populate_t1();
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select count(*) from t1;
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count(*)
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200
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rollback;
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select count(*) from t1;
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count(*)
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0
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begin;
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call populate_t1();
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commit;
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select count(*) from t1;
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count(*)
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200
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truncate table t1;
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select count(*) from t1;
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count(*)
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0
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drop table t1;
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drop procedure populate_t1;
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create temporary table t1 (t1_i int, t1_f float) engine = innodb;
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insert into t1 values (1, 1.1), (2, 2.5), (3, 2.5), (4, 4.4);
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explain select * from t1 where t1_i = 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 4 Using where
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alter table t1 add unique index pri_index(t1_i);
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explain select * from t1 where t1_i = 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 const pri_index pri_index 5 const 1
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select * from t1 where t1_i = 1;
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t1_i t1_f
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1 1.1
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alter table t1 add unique index sec_index(t1_f);
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ERROR 23000: Duplicate entry '2.5' for key 'sec_index'
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alter table t1 add index sec_index(t1_f);
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explain select * from t1 where t1_f >= 2.5;
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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 sec_index sec_index 5 NULL 3 Using index condition
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select * from t1 where t1_f >= 2.5;
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t1_i t1_f
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2 2.5
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3 2.5
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4 4.4
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alter table t1 add column (t1_c char(10));
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select * from t1;
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t1_i t1_f t1_c
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1 1.1 NULL
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2 2.5 NULL
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3 2.5 NULL
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4 4.4 NULL
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insert into t1 values (5, 5.5, 'krunal');
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alter table t1 drop column t1_f;
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show create table t1;
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Table Create Table
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t1 CREATE TEMPORARY TABLE `t1` (
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`t1_i` int(11) DEFAULT NULL,
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`t1_c` char(10) DEFAULT NULL,
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UNIQUE KEY `pri_index` (`t1_i`)
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) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_swedish_ci
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select * from t1 where t1_f >= 2.5;
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ERROR 42S22: Unknown column 't1_f' in 'where clause'
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alter table t1 add index sec_index2(t1_c), algorithm=inplace;
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ERROR 0A000: ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY
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drop table t1;
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create temporary table t1 (i int, f float) engine = innodb;
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insert into t1 values (10, 1.1), (20, 2.2);
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select * from t1;
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i f
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10 1.1
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20 2.2
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alter table t1 discard tablespace;
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ERROR HY000: Cannot DISCARD/IMPORT tablespace associated with temporary table
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alter table t1 import tablespace;
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ERROR HY000: Cannot DISCARD/IMPORT tablespace associated with temporary table
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drop table t1;
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create temporary table t1 (i int) engine=innodb;
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insert into t1 values (1), (2), (3);
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select * from t1;
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i
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1
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2
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3
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alter table t1 rename t2;
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select * from t1;
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ERROR 42S02: Table 'test.t1' doesn't exist
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select * from t2;
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i
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1
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2
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3
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insert into t2 values (1), (2), (6), (7);
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select * from t2;
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i
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1
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2
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3
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1
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2
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6
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7
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drop table t2;
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SET sql_mode = 'NO_ENGINE_SUBSTITUTION';
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = dynamic engine=innodb;
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drop table t;
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = dynamic engine=innodb;
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drop table t;
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = dynamic engine=innodb;
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drop table t;
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SET innodb_strict_mode=OFF;
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = compact engine=innodb;
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ERROR HY000: Index column size too large. The maximum column size is 767 bytes
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = dynamic engine=innodb;
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drop table t;
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = compressed engine=innodb;
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drop table t;
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = compact engine=innodb;
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ERROR HY000: Index column size too large. The maximum column size is 767 bytes
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create temporary table t (
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a int not null,
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b blob not null,
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index sk (b(3021))
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) row_format = dynamic engine=innodb;
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drop table t;
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CREATE TABLE t1 ( i INT ) ENGINE = Innodb;
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CREATE TEMPORARY TABLE t2 ( i INT ) ENGINE = Innodb;
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SELECT COUNT(*) FROM information_schema.INNODB_SYS_TABLES WHERE NAME LIKE '%test%t_';
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COUNT(*)
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1
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CREATE TEMPORARY table t3 ( i INT ) ENGINE = Innodb;
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SELECT COUNT(*) FROM information_schema.INNODB_SYS_TABLES WHERE NAME LIKE '%test%t_';
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COUNT(*)
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1
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DROP TABLE t1,t2,t3;
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SELECT COUNT(*) FROM information_schema.INNODB_SYS_TABLES WHERE NAME LIKE '%test%t_';
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COUNT(*)
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0
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