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#####################################################################
# 1. Prepare
#####################################################################
# Create a normal table
CREATE TABLE t1(
class INT,
id INT,
title VARCHAR(100),
PRIMARY KEY(class)
) ENGINE=InnoDB;
# Create a partition table
CREATE TABLE t2(
class INT,
id INT,
title VARCHAR(100),
PRIMARY KEY(class)
) ENGINE=InnoDB
PARTITION BY RANGE(class) (
PARTITION p0 VALUES LESS THAN (5000),
PARTITION p1 VALUES LESS THAN (10000),
PARTITION p2 VALUES LESS THAN (15000));
# Create a procedure to insert data
CREATE PROCEDURE populate_t1_t2()
BEGIN
DECLARE i int DEFAULT 1;
START TRANSACTION;
WHILE (i <= 1000) DO
INSERT INTO t1 VALUES (i, i, CONCAT('a', i));
INSERT INTO t2 VALUES (i, i, CONCAT('a', i));
SET i = i + 1;
END WHILE;
COMMIT;
END |
# Create a procedure to repeat execute 'select count(*) from partition table'
CREATE PROCEDURE select_count_partition_table()
BEGIN
DECLARE i int DEFAULT 1;
WHILE (i <= 256) DO
SELECT COUNT(*) FROM t2;
SET i = i + 1;
END WHILE;
END |
# Load data
CALL populate_t1_t2();
#####################################################################
# 2. Repeat sql 'select count(*) from t2;' for 256 times.
#####################################################################
SET SESSION innodb_parallel_read_threads = 1;
CALL select_count_partition_table();
#######################################################################
# 3. Parallel read will degrade to single thread read before this patch
#######################################################################
SET SESSION innodb_parallel_read_threads = 16;
SET GLOBAL DEBUG="+d,ib_die_if_not_parallel_read";
SELECT COUNT(*) FROM t1;
COUNT(*)
1000
SELECT COUNT(*) FROM t2;
COUNT(*)
1000
SET GLOBAL DEBUG="-d,ib_die_if_not_parallel_read";
#####################################################################
# 4. Cleanup
#####################################################################
DROP PROCEDURE populate_t1_t2;
DROP PROCEDURE select_count_partition_table;
DROP TABLE t1;
DROP TABLE t2;
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