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6e484c3bd9
ANALYZE FORMAT=JSON output now includes table.r_engine_stats which has the engine statistics. Only non-zero members are printed. Internally: EXPLAIN data structures Explain_table_acccess and Explain_update now have handler* handler_for_stats pointer. It is used to read statistics from handler_for_stats->handler_stats. The following applies only to 10.9+, backport doesn't use it: Explain data structures exist after the tables are closed. We avoid walking invalid pointers using this: - SQL layer calls Explain_query::notify_tables_are_closed() before closing tables. - After that call, printing of JSON output is disabled. Non-JSON output can be printed but we don't access handler_for_stats when doing that.
90 lines
2.1 KiB
Text
90 lines
2.1 KiB
Text
create table t2(a int);
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insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t1 (
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a int not null
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) partition by key(a);
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insert into t1 select a from t2;
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explain partitions select * from t1 where a in (2,3,4);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 p0 ALL NULL NULL NULL NULL 10 Using where
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explain format=json select * from t1 where a in (2,3,4);
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EXPLAIN
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{
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"query_block": {
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"select_id": 1,
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"table": {
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"table_name": "t1",
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"partitions": ["p0"],
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"access_type": "ALL",
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"rows": 10,
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"filtered": 100,
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"attached_condition": "t1.a in (2,3,4)"
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}
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}
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}
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analyze format=json select * from t1 where a in (2,3,4);
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ANALYZE
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{
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"query_block": {
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"select_id": 1,
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"r_loops": 1,
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"r_total_time_ms": "REPLACED",
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"table": {
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"table_name": "t1",
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"partitions": ["p0"],
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"access_type": "ALL",
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"r_loops": 1,
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"rows": 10,
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"r_rows": 10,
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"r_table_time_ms": "REPLACED",
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"r_other_time_ms": "REPLACED",
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"r_engine_stats": REPLACED,
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"filtered": 100,
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"r_filtered": 30,
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"attached_condition": "t1.a in (2,3,4)"
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}
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}
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}
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analyze format=json update t1 set a=a+10 where a in (2,3,4);
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ANALYZE
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{
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"query_block": {
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"select_id": 1,
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"r_total_time_ms": "REPLACED",
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"buffer": {
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"table": {
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"update": 1,
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"table_name": "t1",
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"partitions": ["p0"],
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"access_type": "ALL",
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"rows": 10,
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"r_rows": 10,
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"r_filtered": 30,
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"r_total_time_ms": "REPLACED",
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"r_engine_stats": REPLACED,
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"attached_condition": "t1.a in (2,3,4)"
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}
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}
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}
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}
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analyze format=json delete from t1 where a in (20,30,40);
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ANALYZE
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{
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"query_block": {
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"select_id": 1,
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"r_total_time_ms": "REPLACED",
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"table": {
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"delete": 1,
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"table_name": "t1",
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"partitions": ["p0"],
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"access_type": "ALL",
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"rows": 10,
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"r_rows": 10,
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"r_filtered": 0,
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"r_total_time_ms": "REPLACED",
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"r_engine_stats": REPLACED,
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"attached_condition": "t1.a in (20,30,40)"
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}
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}
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}
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drop table t1,t2;
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