122 lines
3.5 KiB
Plaintext
122 lines
3.5 KiB
Plaintext
#
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# Test of the cost constants when restarting the server
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#
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# To get stable cost estimates, the test should only be run with
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# 16K InnoDB page size.
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#
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# Test that changes to cost constants are used after restarting server
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#
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# Verify that the content of the two cost constants tables are as expected
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SELECT cost_name,cost_value FROM mysql.server_cost;
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SELECT engine_name,cost_name,cost_value FROM mysql.engine_cost;
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#
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# Create a test database that will be used for running queries
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#
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CREATE TABLE t0 (
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i1 INTEGER
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);
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INSERT INTO t0 VALUE (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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# Create a table with 100 records each having size approximately 1000 bytes
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CREATE TABLE t1_innodb (
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pk INTEGER PRIMARY KEY,
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i1 INTEGER NOT NULL,
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c1 CHAR(250),
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c2 CHAR(250),
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c3 CHAR(250),
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c4 CHAR(250),
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INDEX i1_key (i1)
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) ENGINE=InnoDB;
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--echo # Since ANALYZE TABLE only reads a subset of the data, the statistics for
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--echo # table t1 depends on the row order. And since the INSERT INTO ... SELECT
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--echo # may be executed using different execution plans, we've added ORDER BY
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--echo # to ensure that we rows has the same order every time. If not, the
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--echo # estimated number of rows in EXPLAIN may change on different platforms.
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INSERT INTO t1_innodb
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SELECT a0.i1 + 10 * a1.i1, a0.i1, 'abc', 'def', 'ghi', 'jkl'
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FROM t0 AS a0, t0 AS a1 ORDER BY a0.i1, a1.i1;
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ANALYZE TABLE t1_innodb;
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# Run the query to see cost estimates when run with default cost constants
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let query_innodb= SELECT * FROM t1_innodb;
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--echo "Explain with cost estimate against InnoDB"
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eval EXPLAIN FORMAT=JSON $query_innodb;
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#
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# Update one cost constant in the server cost table and the two cost
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# constants in the engine cost table (the reason for updating both is that
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# after a restart the statistics about whether pages are in memory or on disk
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# may vary). The new value is double of the default value.
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#
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UPDATE mysql.server_cost
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SET cost_value=0.4
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WHERE cost_name="row_evaluate_cost";
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UPDATE mysql.engine_cost
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SET cost_value=2.0
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WHERE cost_name="memory_block_read_cost";
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UPDATE mysql.engine_cost
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SET cost_value=2.0
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WHERE cost_name="io_block_read_cost";
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--echo "Restarting MySQL server"
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--source include/restart_mysqld.inc
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--echo "MySQL restarted"
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SELECT cost_name, cost_value FROM mysql.server_cost;
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SELECT engine_name, cost_name, cost_value FROM mysql.engine_cost;
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#
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# Run the two queries and validate that the cost estimate has doubled
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#
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--echo "Explain with cost estimate against MyISAM"
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eval EXPLAIN FORMAT=JSON $query_innodb;
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# Reset the cost constants
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UPDATE mysql.server_cost
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SET cost_value=DEFAULT;
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UPDATE mysql.engine_cost
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SET cost_value=DEFAULT;
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#
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# Test that adding engine specific cost constants does not influence
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# other engines.
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#
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INSERT INTO mysql.engine_cost VALUES
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("InnoDB", 0, "memory_block_read_cost", 4.0, CURRENT_TIMESTAMP, DEFAULT, DEFAULT);
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INSERT INTO mysql.engine_cost VALUES
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("InnoDB", 0, "io_block_read_cost", 4.0, CURRENT_TIMESTAMP, DEFAULT, DEFAULT);
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--echo "Restarting MySQL server"
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--source include/restart_mysqld.inc
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--echo "MySQL restarted"
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SELECT cost_name, cost_value FROM mysql.server_cost;
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SELECT engine_name, cost_name, cost_value FROM mysql.engine_cost;
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#
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# Run the query and validate that the query against InnoDB has
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# read cost four times the original
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#
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--echo "Explain with cost estimate against InnoDB"
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eval EXPLAIN FORMAT=JSON $query_innodb;
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# Delete the added entry for InnoDB
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DELETE FROM mysql.engine_cost
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WHERE engine_name NOT LIKE "default";
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--echo "Restarting MySQL server"
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--source include/restart_mysqld.inc
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DROP TABLE t0, t1_innodb;
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