DROP TABLE IF EXISTS t1;
DROP TABLE IF EXISTS t2;
CREATE TABLE t1 (i INT, j INT, PRIMARY KEY (i)) ENGINE = XENGINE;
CREATE TABLE t2 (k INT, PRIMARY KEY (k)) ENGINE = XENGINE;
INSERT INTO t1 VALUES (1,1), (2,2), (3,3), (4,4), (5,5);
SELECT * FROM INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT WHERE TABLE_NAME = 't1';
TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	STAT_TYPE	VALUE
SELECT * FROM INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT_GLOBAL;
STAT_TYPE	VALUE
SELECT * FROM INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT
WHERE TABLE_NAME = 't1'
AND STAT_TYPE in ('INTERNAL_KEY_SKIPPED_COUNT', 'INTERNAL_DELETE_SKIPPED_COUNT');
TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	STAT_TYPE	VALUE
SELECT * FROM t1;
i	j
1	1
2	2
3	3
4	4
5	5
SELECT * FROM INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT
WHERE TABLE_NAME = 't1'
AND STAT_TYPE in ('INTERNAL_KEY_SKIPPED_COUNT', 'INTERNAL_DELETE_SKIPPED_COUNT');
TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	STAT_TYPE	VALUE
SELECT * FROM t1 WHERE j BETWEEN 1 AND 5;
i	j
1	1
2	2
3	3
4	4
5	5
SELECT * FROM INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT
WHERE TABLE_NAME = 't1'
AND STAT_TYPE in ('INTERNAL_KEY_SKIPPED_COUNT', 'INTERNAL_DELETE_SKIPPED_COUNT');
TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	STAT_TYPE	VALUE
BEGIN;
INSERT INTO t2 VALUES (1), (2);
INSERT INTO t2 VALUES (3), (4);
COMMIT;
SELECT COUNT(*) from INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT
WHERE TABLE_NAME = 't2'
AND STAT_TYPE = 'IO_WRITE_NANOS'
AND VALUE > 0;
COUNT(*)
0
SELECT COUNT(*) from INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT_GLOBAL
WHERE STAT_TYPE = 'IO_WRITE_NANOS' AND VALUE > 0;
COUNT(*)
0
SELECT VALUE INTO @a from INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT_GLOBAL
WHERE STAT_TYPE = 'IO_WRITE_NANOS';
Warnings:
Warning	1329	No data - zero rows fetched, selected, or processed
INSERT INTO t2 VALUES (5), (6), (7), (8);
SELECT COUNT(*) from INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT
WHERE TABLE_NAME = 't2'
AND STAT_TYPE = 'IO_WRITE_NANOS'
AND VALUE > 0;
COUNT(*)
0
SELECT VALUE INTO @b from INFORMATION_SCHEMA.XENGINE_PERF_CONTEXT_GLOBAL
WHERE STAT_TYPE = 'IO_WRITE_NANOS';
Warnings:
Warning	1329	No data - zero rows fetched, selected, or processed
SELECT CASE WHEN @b - @a > 0 THEN 'true' ELSE 'false' END;
CASE WHEN @b - @a > 0 THEN 'true' ELSE 'false' END
false
DROP TABLE t1;
DROP TABLE t2;