use test; drop table if exists t1, t2, t3, t4; create table t1 (c1 int primary key, c2 int, c3 int, index c2 (c2)); create table t2 (c1 int unique, c2 int); insert into t2 values(1, 0), (2, 1); create table t3 (a bigint, b bigint, c bigint, d bigint); create table t4 (a int, b int, c int, index idx(a, b), primary key(a)); create index expr_idx on t4((a+b+1)); set @@session.tidb_opt_agg_push_down = 1; set @@session.tidb_opt_insubq_to_join_and_agg=1; set @@session.tidb_hashagg_partial_concurrency = 1; set @@session.tidb_hashagg_final_concurrency = 1; set @@session.tidb_window_concurrency = 1; explain select * from t3 where exists (select s.a from t3 s having sum(s.a) = t3.a ); id estRows task access object operator info HashJoin_12 8000.00 root semi join, equal:[eq(Column#13, Column#11)] ├─StreamAgg_27(Build) 1.00 root funcs:sum(Column#16)->Column#11 │ └─TableReader_28 1.00 root data:StreamAgg_19 │ └─StreamAgg_19 1.00 cop[tikv] funcs:sum(test.t3.a)->Column#16 │ └─TableFullScan_26 10000.00 cop[tikv] table:s keep order:false, stats:pseudo └─Projection_13(Probe) 10000.00 root test.t3.a, test.t3.b, test.t3.c, test.t3.d, cast(test.t3.a, decimal(20,0) BINARY)->Column#13 └─TableReader_15 10000.00 root data:TableFullScan_14 └─TableFullScan_14 10000.00 cop[tikv] table:t3 keep order:false, stats:pseudo explain select * from t1; id estRows task access object operator info TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select * from t1 order by c2; id estRows task access object operator info IndexLookUp_12 10000.00 root ├─IndexFullScan_10(Build) 10000.00 cop[tikv] table:t1, index:c2(c2) keep order:true, stats:pseudo └─TableRowIDScan_11(Probe) 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select * from t2 order by c2; id estRows task access object operator info Sort_4 10000.00 root test.t2.c2:asc └─TableReader_8 10000.00 root data:TableFullScan_7 └─TableFullScan_7 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo explain select * from t1 where t1.c1 > 0; id estRows task access object operator info TableReader_6 3333.33 root data:TableRangeScan_5 └─TableRangeScan_5 3333.33 cop[tikv] table:t1 range:(0,+inf], keep order:false, stats:pseudo explain select t1.c1, t1.c2 from t1 where t1.c2 = 1; id estRows task access object operator info IndexReader_6 10.00 root index:IndexRangeScan_5 └─IndexRangeScan_5 10.00 cop[tikv] table:t1, index:c2(c2) range:[1,1], keep order:false, stats:pseudo explain select * from t1 left join t2 on t1.c2 = t2.c1 where t1.c1 > 1; id estRows task access object operator info HashJoin_16 4166.67 root left outer join, equal:[eq(test.t1.c2, test.t2.c1)] ├─TableReader_26(Build) 3333.33 root data:TableRangeScan_25 │ └─TableRangeScan_25 3333.33 cop[tikv] table:t1 range:(1,+inf], keep order:false, stats:pseudo └─TableReader_29(Probe) 9990.00 root data:Selection_28 └─Selection_28 9990.00 cop[tikv] not(isnull(test.t2.c1)) └─TableFullScan_27 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo explain update t1 set t1.c2 = 2 where t1.c1 = 1; id estRows task access object operator info Update_2 N/A root N/A └─Point_Get_1 1.00 root table:t1 handle:1 explain delete from t1 where t1.c2 = 1; id estRows task access object operator info Delete_4 N/A root N/A └─IndexLookUp_11 10.00 root ├─IndexRangeScan_9(Build) 10.00 cop[tikv] table:t1, index:c2(c2) range:[1,1], keep order:false, stats:pseudo └─TableRowIDScan_10(Probe) 10.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select count(b.c2) from t1 a, t2 b where a.c1 = b.c2 group by a.c1; id estRows task access object operator info Projection_11 9990.00 root cast(Column#8, bigint(21) BINARY)->Column#7 └─HashJoin_17 9990.00 root inner join, equal:[eq(test.t1.c1, test.t2.c2)] ├─HashAgg_24(Build) 7992.00 root group by:test.t2.c2, funcs:count(Column#9)->Column#8, funcs:firstrow(test.t2.c2)->test.t2.c2 │ └─TableReader_25 7992.00 root data:HashAgg_19 │ └─HashAgg_19 7992.00 cop[tikv] group by:test.t2.c2, funcs:count(test.t2.c2)->Column#9 │ └─Selection_23 9990.00 cop[tikv] not(isnull(test.t2.c2)) │ └─TableFullScan_22 10000.00 cop[tikv] table:b keep order:false, stats:pseudo └─TableReader_30(Probe) 10000.00 root data:TableFullScan_29 └─TableFullScan_29 10000.00 cop[tikv] table:a keep order:false, stats:pseudo explain select * from t2 order by t2.c2 limit 0, 1; id estRows task access object operator info TopN_7 1.00 root test.t2.c2:asc, offset:0, count:1 └─TableReader_15 1.00 root data:TopN_14 └─TopN_14 1.00 cop[tikv] test.t2.c2:asc, offset:0, count:1 └─TableFullScan_13 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo explain select * from t1 where c1 > 1 and c2 = 1 and c3 < 1; id estRows task access object operator info IndexLookUp_11 11.08 root ├─IndexRangeScan_8(Build) 33.33 cop[tikv] table:t1, index:c2(c2) range:(1 1,1 +inf], keep order:false, stats:pseudo └─Selection_10(Probe) 11.08 cop[tikv] lt(test.t1.c3, 1) └─TableRowIDScan_9 33.33 cop[tikv] table:t1 keep order:false, stats:pseudo explain select * from t1 where c1 = 1 and c2 > 1; id estRows task access object operator info Selection_6 0.33 root gt(test.t1.c2, 1) └─Point_Get_5 1.00 root table:t1 handle:1 explain select sum(t1.c1 in (select c1 from t2)) from t1; id estRows task access object operator info StreamAgg_12 1.00 root funcs:sum(Column#10)->Column#8 └─Projection_23 10000.00 root cast(Column#7, decimal(65,0) BINARY)->Column#10 └─HashJoin_22 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t1.c1, test.t2.c1) ├─IndexReader_21(Build) 10000.00 root index:IndexFullScan_20 │ └─IndexFullScan_20 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:false, stats:pseudo └─TableReader_15(Probe) 10000.00 root data:TableFullScan_14 └─TableFullScan_14 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select c1 from t1 where c1 in (select c2 from t2); id estRows task access object operator info HashJoin_15 9990.00 root inner join, equal:[eq(test.t1.c1, test.t2.c2)] ├─HashAgg_19(Build) 7992.00 root group by:test.t2.c2, funcs:firstrow(test.t2.c2)->test.t2.c2 │ └─TableReader_26 9990.00 root data:Selection_25 │ └─Selection_25 9990.00 cop[tikv] not(isnull(test.t2.c2)) │ └─TableFullScan_24 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo └─TableReader_28(Probe) 10000.00 root data:TableFullScan_27 └─TableFullScan_27 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select (select count(1) k from t1 s where s.c1 = t1.c1 having k != 0) from t1; id estRows task access object operator info Projection_12 10000.00 root ifnull(Column#7, 0)->Column#7 └─MergeJoin_13 10000.00 root left outer join, left key:test.t1.c1, right key:test.t1.c1 ├─Projection_18(Build) 8000.00 root 1->Column#7, test.t1.c1 │ └─TableReader_20 10000.00 root data:TableFullScan_19 │ └─TableFullScan_19 10000.00 cop[tikv] table:s keep order:true, stats:pseudo └─TableReader_17(Probe) 10000.00 root data:TableFullScan_16 └─TableFullScan_16 10000.00 cop[tikv] table:t1 keep order:true, stats:pseudo explain select * from information_schema.columns; id estRows task access object operator info MemTableScan_4 10000.00 root table:COLUMNS explain select c2 = (select c2 from t2 where t1.c1 = t2.c1 order by c1 limit 1) from t1; id estRows task access object operator info Projection_12 10000.00 root eq(test.t1.c2, test.t2.c2)->Column#8 └─Apply_14 10000.00 root CARTESIAN left outer join ├─TableReader_16(Build) 10000.00 root data:TableFullScan_15 │ └─TableFullScan_15 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo └─Projection_43(Probe) 1.00 root test.t2.c1, test.t2.c2 └─IndexLookUp_42 1.00 root limit embedded(offset:0, count:1) ├─Limit_41(Build) 1.00 cop[tikv] offset:0, count:1 │ └─IndexRangeScan_39 1.00 cop[tikv] table:t2, index:c1(c1) range: decided by [eq(test.t1.c1, test.t2.c1)], keep order:true, stats:pseudo └─TableRowIDScan_40(Probe) 1.00 cop[tikv] table:t2 keep order:false, stats:pseudo explain select * from t1 order by c1 desc limit 1; id estRows task access object operator info Limit_10 1.00 root offset:0, count:1 └─TableReader_20 1.00 root data:Limit_19 └─Limit_19 1.00 cop[tikv] offset:0, count:1 └─TableFullScan_18 1.00 cop[tikv] table:t1 keep order:true, desc, stats:pseudo explain select * from t4 use index(idx) where a > 1 and b > 1 and c > 1 limit 1; id estRows task access object operator info Limit_9 1.00 root offset:0, count:1 └─IndexLookUp_16 1.00 root ├─Selection_13(Build) 3.00 cop[tikv] gt(test.t4.b, 1) │ └─IndexRangeScan_11 9.00 cop[tikv] table:t4, index:idx(a, b) range:(1,+inf], keep order:false, stats:pseudo └─Limit_15(Probe) 1.00 cop[tikv] offset:0, count:1 └─Selection_14 1.00 cop[tikv] gt(test.t4.c, 1) └─TableRowIDScan_12 3.00 cop[tikv] table:t4 keep order:false, stats:pseudo explain select * from t4 where a > 1 and c > 1 limit 1; id estRows task access object operator info Limit_8 1.00 root offset:0, count:1 └─TableReader_14 1.00 root data:Limit_13 └─Limit_13 1.00 cop[tikv] offset:0, count:1 └─Selection_12 1.00 cop[tikv] gt(test.t4.c, 1) └─TableRangeScan_11 3.00 cop[tikv] table:t4 range:(1,+inf], keep order:false, stats:pseudo explain select ifnull(null, t1.c1) from t1; id estRows task access object operator info TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select if(10, t1.c1, t1.c2) from t1; id estRows task access object operator info TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select c1 from t2 union select c1 from t2 union all select c1 from t2; id estRows task access object operator info Union_17 26000.00 root ├─HashAgg_21 16000.00 root group by:Column#10, funcs:firstrow(Column#12)->Column#10 │ └─Union_22 16000.00 root │ ├─StreamAgg_27 8000.00 root group by:test.t2.c1, funcs:firstrow(test.t2.c1)->Column#12, funcs:firstrow(test.t2.c1)->Column#10 │ │ └─IndexReader_40 10000.00 root index:IndexFullScan_39 │ │ └─IndexFullScan_39 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:true, stats:pseudo │ └─StreamAgg_45 8000.00 root group by:test.t2.c1, funcs:firstrow(test.t2.c1)->Column#12, funcs:firstrow(test.t2.c1)->Column#10 │ └─IndexReader_58 10000.00 root index:IndexFullScan_57 │ └─IndexFullScan_57 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:true, stats:pseudo └─IndexReader_63 10000.00 root index:IndexFullScan_62 └─IndexFullScan_62 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:false, stats:pseudo explain select c1 from t2 union all select c1 from t2 union select c1 from t2; id estRows task access object operator info HashAgg_18 24000.00 root group by:Column#10, funcs:firstrow(Column#11)->Column#10 └─Union_19 24000.00 root ├─StreamAgg_24 8000.00 root group by:test.t2.c1, funcs:firstrow(test.t2.c1)->Column#11, funcs:firstrow(test.t2.c1)->Column#10 │ └─IndexReader_37 10000.00 root index:IndexFullScan_36 │ └─IndexFullScan_36 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:true, stats:pseudo ├─StreamAgg_42 8000.00 root group by:test.t2.c1, funcs:firstrow(test.t2.c1)->Column#11, funcs:firstrow(test.t2.c1)->Column#10 │ └─IndexReader_55 10000.00 root index:IndexFullScan_54 │ └─IndexFullScan_54 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:true, stats:pseudo └─StreamAgg_60 8000.00 root group by:test.t2.c1, funcs:firstrow(test.t2.c1)->Column#11, funcs:firstrow(test.t2.c1)->Column#10 └─IndexReader_73 10000.00 root index:IndexFullScan_72 └─IndexFullScan_72 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:true, stats:pseudo select * from information_schema.tidb_indexes where table_name='t4'; TABLE_SCHEMA TABLE_NAME NON_UNIQUE KEY_NAME SEQ_IN_INDEX COLUMN_NAME SUB_PART INDEX_COMMENT Expression INDEX_ID test t4 0 PRIMARY 1 a NULL NULL 0 test t4 1 idx 1 a NULL NULL 1 test t4 1 idx 2 b NULL NULL 1 test t4 1 expr_idx 1 NULL NULL (`a` + `b` + 1) 2 explain select count(1) from (select count(1) from (select * from t1 where c3 = 100) k) k2; id estRows task access object operator info StreamAgg_13 1.00 root funcs:count(1)->Column#5 └─StreamAgg_28 1.00 root funcs:firstrow(Column#9)->Column#7 └─TableReader_29 1.00 root data:StreamAgg_17 └─StreamAgg_17 1.00 cop[tikv] funcs:firstrow(1)->Column#9 └─Selection_27 10.00 cop[tikv] eq(test.t1.c3, 100) └─TableFullScan_26 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select 1 from (select count(c2), count(c3) from t1) k; id estRows task access object operator info Projection_5 1.00 root 1->Column#6 └─StreamAgg_21 1.00 root funcs:firstrow(Column#14)->Column#9 └─TableReader_22 1.00 root data:StreamAgg_9 └─StreamAgg_9 1.00 cop[tikv] funcs:firstrow(1)->Column#14 └─TableFullScan_19 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select count(1) from (select max(c2), count(c3) as m from t1) k; id estRows task access object operator info StreamAgg_11 1.00 root funcs:count(1)->Column#6 └─StreamAgg_27 1.00 root funcs:firstrow(Column#13)->Column#8 └─TableReader_28 1.00 root data:StreamAgg_15 └─StreamAgg_15 1.00 cop[tikv] funcs:firstrow(1)->Column#13 └─TableFullScan_25 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select count(1) from (select count(c2) from t1 group by c3) k; id estRows task access object operator info StreamAgg_11 1.00 root funcs:count(1)->Column#5 └─HashAgg_22 8000.00 root group by:test.t1.c3, funcs:firstrow(1)->Column#7 └─TableReader_19 10000.00 root data:TableFullScan_18 └─TableFullScan_18 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo set @@session.tidb_opt_insubq_to_join_and_agg=0; explain select sum(t1.c1 in (select c1 from t2)) from t1; id estRows task access object operator info StreamAgg_12 1.00 root funcs:sum(Column#10)->Column#8 └─Projection_23 10000.00 root cast(Column#7, decimal(65,0) BINARY)->Column#10 └─HashJoin_22 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t1.c1, test.t2.c1) ├─IndexReader_21(Build) 10000.00 root index:IndexFullScan_20 │ └─IndexFullScan_20 10000.00 cop[tikv] table:t2, index:c1(c1) keep order:false, stats:pseudo └─TableReader_15(Probe) 10000.00 root data:TableFullScan_14 └─TableFullScan_14 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select 1 in (select c2 from t2) from t1; id estRows task access object operator info HashJoin_7 10000.00 root CARTESIAN left outer semi join, other cond:eq(1, test.t2.c2) ├─TableReader_13(Build) 10000.00 root data:TableFullScan_12 │ └─TableFullScan_12 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo └─TableReader_9(Probe) 10000.00 root data:TableFullScan_8 └─TableFullScan_8 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select sum(6 in (select c2 from t2)) from t1; id estRows task access object operator info StreamAgg_12 1.00 root funcs:sum(Column#10)->Column#8 └─Projection_21 10000.00 root cast(Column#7, decimal(65,0) BINARY)->Column#10 └─HashJoin_20 10000.00 root CARTESIAN left outer semi join, other cond:eq(6, test.t2.c2) ├─TableReader_19(Build) 10000.00 root data:TableFullScan_18 │ └─TableFullScan_18 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo └─TableReader_15(Probe) 10000.00 root data:TableFullScan_14 └─TableFullScan_14 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain format="dot" select sum(t1.c1 in (select c1 from t2)) from t1; dot contents digraph StreamAgg_12 { subgraph cluster12{ node [style=filled, color=lightgrey] color=black label = "root" "StreamAgg_12" -> "Projection_23" "Projection_23" -> "HashJoin_22" "HashJoin_22" -> "TableReader_15" "HashJoin_22" -> "IndexReader_21" } subgraph cluster14{ node [style=filled, color=lightgrey] color=black label = "cop" "TableFullScan_14" } subgraph cluster20{ node [style=filled, color=lightgrey] color=black label = "cop" "IndexFullScan_20" } "TableReader_15" -> "TableFullScan_14" "IndexReader_21" -> "IndexFullScan_20" } explain format="dot" select 1 in (select c2 from t2) from t1; dot contents digraph HashJoin_7 { subgraph cluster7{ node [style=filled, color=lightgrey] color=black label = "root" "HashJoin_7" -> "TableReader_9" "HashJoin_7" -> "TableReader_13" } subgraph cluster8{ node [style=filled, color=lightgrey] color=black label = "cop" "TableFullScan_8" } subgraph cluster12{ node [style=filled, color=lightgrey] color=black label = "cop" "TableFullScan_12" } "TableReader_9" -> "TableFullScan_8" "TableReader_13" -> "TableFullScan_12" } drop table if exists t1, t2, t3, t4; drop table if exists t; create table t(a int primary key, b int, c int, index idx(b)); explain select t.c in (select count(*) from t s ignore index(idx), t t1 where s.a = t.a and s.a = t1.a) from t; id estRows task access object operator info Projection_11 10000.00 root Column#11 └─Apply_13 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_15(Build) 10000.00 root data:TableFullScan_14 │ └─TableFullScan_14 10000.00 cop[tikv] table:t keep order:false, stats:pseudo └─StreamAgg_20(Probe) 1.00 root funcs:count(1)->Column#10 └─MergeJoin_44 12.50 root inner join, left key:test.t.a, right key:test.t.a ├─TableReader_39(Build) 1.00 root data:TableRangeScan_38 │ └─TableRangeScan_38 1.00 cop[tikv] table:t1 range: decided by [eq(test.t.a, test.t.a)], keep order:true, stats:pseudo └─TableReader_37(Probe) 1.00 root data:TableRangeScan_36 └─TableRangeScan_36 1.00 cop[tikv] table:s range: decided by [eq(test.t.a, test.t.a)], keep order:true, stats:pseudo explain select t.c in (select count(*) from t s use index(idx), t t1 where s.b = t.a and s.a = t1.a) from t; id estRows task access object operator info Projection_11 10000.00 root Column#11 └─Apply_13 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_15(Build) 10000.00 root data:TableFullScan_14 │ └─TableFullScan_14 10000.00 cop[tikv] table:t keep order:false, stats:pseudo └─StreamAgg_20(Probe) 1.00 root funcs:count(1)->Column#10 └─IndexJoin_36 12.50 root inner join, inner:TableReader_35, outer key:test.t.a, inner key:test.t.a, equal cond:eq(test.t.a, test.t.a) ├─IndexReader_29(Build) 10.00 root index:IndexRangeScan_28 │ └─IndexRangeScan_28 10.00 cop[tikv] table:s, index:idx(b) range: decided by [eq(test.t.b, test.t.a)], keep order:false, stats:pseudo └─TableReader_35(Probe) 1.00 root data:TableRangeScan_34 └─TableRangeScan_34 1.00 cop[tikv] table:t1 range: decided by [test.t.a], keep order:false, stats:pseudo explain select t.c in (select count(*) from t s use index(idx), t t1 where s.b = t.a and s.c = t1.a) from t; id estRows task access object operator info Projection_11 10000.00 root Column#11 └─Apply_13 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_15(Build) 10000.00 root data:TableFullScan_14 │ └─TableFullScan_14 10000.00 cop[tikv] table:t keep order:false, stats:pseudo └─StreamAgg_20(Probe) 1.00 root funcs:count(1)->Column#10 └─IndexJoin_38 12.49 root inner join, inner:TableReader_37, outer key:test.t.c, inner key:test.t.a, equal cond:eq(test.t.c, test.t.a) ├─IndexLookUp_31(Build) 9.99 root │ ├─IndexRangeScan_28(Build) 10.00 cop[tikv] table:s, index:idx(b) range: decided by [eq(test.t.b, test.t.a)], keep order:false, stats:pseudo │ └─Selection_30(Probe) 9.99 cop[tikv] not(isnull(test.t.c)) │ └─TableRowIDScan_29 10.00 cop[tikv] table:s keep order:false, stats:pseudo └─TableReader_37(Probe) 1.00 root data:TableRangeScan_36 └─TableRangeScan_36 1.00 cop[tikv] table:t1 range: decided by [test.t.c], keep order:false, stats:pseudo insert into t values(1, 1, 1), (2, 2 ,2), (3, 3, 3), (4, 3, 4),(5,3,5); analyze table t; explain select t.c in (select count(*) from t s, t t1 where s.b = t.a and s.b = 3 and s.a = t1.a) from t; id estRows task access object operator info Projection_11 5.00 root Column#11 └─Apply_13 5.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_15(Build) 5.00 root data:TableFullScan_14 │ └─TableFullScan_14 5.00 cop[tikv] table:t keep order:false └─StreamAgg_20(Probe) 1.00 root funcs:count(1)->Column#10 └─MergeJoin_52 2.40 root inner join, left key:test.t.a, right key:test.t.a ├─TableReader_42(Build) 4.00 root data:Selection_41 │ └─Selection_41 4.00 cop[tikv] eq(3, test.t.a) │ └─TableFullScan_40 5.00 cop[tikv] table:t1 keep order:true └─IndexReader_39(Probe) 2.40 root index:Selection_38 └─Selection_38 2.40 cop[tikv] eq(3, test.t.a) └─IndexRangeScan_37 3.00 cop[tikv] table:s, index:idx(b) range:[3,3], keep order:true explain select t.c in (select count(*) from t s left join t t1 on s.a = t1.a where 3 = t.a and s.b = 3) from t; id estRows task access object operator info Projection_10 5.00 root Column#11 └─Apply_12 5.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_14(Build) 5.00 root data:TableFullScan_13 │ └─TableFullScan_13 5.00 cop[tikv] table:t keep order:false └─StreamAgg_19(Probe) 1.00 root funcs:count(1)->Column#10 └─MergeJoin_45 2.40 root left outer join, left key:test.t.a, right key:test.t.a ├─TableReader_35(Build) 4.00 root data:Selection_34 │ └─Selection_34 4.00 cop[tikv] eq(3, test.t.a) │ └─TableFullScan_33 5.00 cop[tikv] table:t1 keep order:true └─IndexReader_32(Probe) 2.40 root index:Selection_31 └─Selection_31 2.40 cop[tikv] eq(3, test.t.a) └─IndexRangeScan_30 3.00 cop[tikv] table:s, index:idx(b) range:[3,3], keep order:true explain select t.c in (select count(*) from t s right join t t1 on s.a = t1.a where 3 = t.a and t1.b = 3) from t; id estRows task access object operator info Projection_10 5.00 root Column#11 └─Apply_12 5.00 root CARTESIAN left outer semi join, other cond:eq(test.t.c, Column#10) ├─TableReader_14(Build) 5.00 root data:TableFullScan_13 │ └─TableFullScan_13 5.00 cop[tikv] table:t keep order:false └─StreamAgg_19(Probe) 1.00 root funcs:count(1)->Column#10 └─MergeJoin_44 2.40 root right outer join, left key:test.t.a, right key:test.t.a ├─TableReader_31(Build) 4.00 root data:Selection_30 │ └─Selection_30 4.00 cop[tikv] eq(3, test.t.a) │ └─TableFullScan_29 5.00 cop[tikv] table:s keep order:true └─IndexReader_34(Probe) 2.40 root index:Selection_33 └─Selection_33 2.40 cop[tikv] eq(3, test.t.a) └─IndexRangeScan_32 3.00 cop[tikv] table:t1, index:idx(b) range:[3,3], keep order:true drop table if exists t; create table t(a int unsigned); explain select t.a = '123455' from t; id estRows task access object operator info Projection_3 10000.00 root eq(test.t.a, 123455)->Column#3 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select t.a > '123455' from t; id estRows task access object operator info Projection_3 10000.00 root gt(test.t.a, 123455)->Column#3 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select t.a != '123455' from t; id estRows task access object operator info Projection_3 10000.00 root ne(test.t.a, 123455)->Column#3 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select t.a = 12345678912345678998789678687678.111 from t; id estRows task access object operator info Projection_3 10000.00 root 0->Column#3 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo drop table if exists t; create table t(a bigint, b bigint, index idx(a, b)); explain select * from t where a in (1, 2) and a in (1, 3); id estRows task access object operator info IndexReader_6 10.00 root index:IndexRangeScan_5 └─IndexRangeScan_5 10.00 cop[tikv] table:t, index:idx(a, b) range:[1,1], keep order:false, stats:pseudo explain select * from t where b in (1, 2) and b in (1, 3); id estRows task access object operator info TableReader_7 10.00 root data:Selection_6 └─Selection_6 10.00 cop[tikv] in(test.t.b, 1, 2), in(test.t.b, 1, 3) └─TableFullScan_5 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select * from t where a = 1 and a = 1; id estRows task access object operator info IndexReader_6 10.00 root index:IndexRangeScan_5 └─IndexRangeScan_5 10.00 cop[tikv] table:t, index:idx(a, b) range:[1,1], keep order:false, stats:pseudo explain select * from t where a = 1 and a = 2; id estRows task access object operator info TableDual_5 0.00 root rows:0 explain select * from t where b = 1 and b = 2; id estRows task access object operator info TableDual_5 0.00 root rows:0 explain select * from t t1 join t t2 where t1.b = t2.b and t2.b is null; id estRows task access object operator info Projection_7 0.00 root test.t.a, test.t.b, test.t.a, test.t.b └─HashJoin_9 0.00 root inner join, equal:[eq(test.t.b, test.t.b)] ├─TableReader_12(Build) 0.00 root data:Selection_11 │ └─Selection_11 0.00 cop[tikv] isnull(test.t.b), not(isnull(test.t.b)) │ └─TableFullScan_10 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo └─TableReader_18(Probe) 9990.00 root data:Selection_17 └─Selection_17 9990.00 cop[tikv] not(isnull(test.t.b)) └─TableFullScan_16 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo explain select * from t t1 where not exists (select * from t t2 where t1.b = t2.b); id estRows task access object operator info HashJoin_9 8000.00 root anti semi join, equal:[eq(test.t.b, test.t.b)] ├─TableReader_15(Build) 10000.00 root data:TableFullScan_14 │ └─TableFullScan_14 10000.00 cop[tikv] table:t2 keep order:false, stats:pseudo └─TableReader_11(Probe) 10000.00 root data:TableFullScan_10 └─TableFullScan_10 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo drop table if exists t; create table t(a bigint primary key); explain select * from t where a = 1 and a = 2; id estRows task access object operator info TableDual_5 0.00 root rows:0 explain select null or a > 1 from t; id estRows task access object operator info Projection_3 10000.00 root or(, gt(test.t.a, 1))->Column#2 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select * from t where a = 1 for update; id estRows task access object operator info Point_Get_1 1.00 root table:t handle:1, lock drop table if exists ta, tb; create table ta (a varchar(20)); create table tb (a varchar(20)); begin; insert tb values ('1'); explain select * from ta where a = 1; id estRows task access object operator info TableReader_7 8000.00 root data:Selection_6 └─Selection_6 8000.00 cop[tikv] eq(cast(test.ta.a), 1) └─TableFullScan_5 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo rollback; drop table if exists t1, t2; create table t1(a int, b int, c int, primary key(a, b)); create table t2(a int, b int, c int, primary key(a)); explain select t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a; id estRows task access object operator info IndexReader_9 10000.00 root index:IndexFullScan_8 └─IndexFullScan_8 10000.00 cop[tikv] table:t1, index:PRIMARY(a, b) keep order:false, stats:pseudo explain select distinct t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a; id estRows task access object operator info IndexReader_11 10000.00 root index:IndexFullScan_10 └─IndexFullScan_10 10000.00 cop[tikv] table:t1, index:PRIMARY(a, b) keep order:false, stats:pseudo CREATE TABLE `test01` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `stat_date` int(11) NOT NULL DEFAULT '0', `show_date` varchar(20) NOT NULL DEFAULT '', `region_id` bigint(20) unsigned NOT NULL DEFAULT '0', `period` tinyint(3) unsigned NOT NULL DEFAULT '0', `registration_num` bigint(20) unsigned NOT NULL DEFAULT '0', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin; CREATE TABLE `test02` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `region_name` varchar(128) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin; EXPLAIN SELECT COUNT(1) FROM (SELECT COALESCE(b.region_name, '不详') region_name, SUM(a.registration_num) registration_num FROM (SELECT stat_date, show_date, region_id, 0 registration_num FROM test01 WHERE period = 1 AND stat_date >= 20191202 AND stat_date <= 20191202 UNION ALL SELECT stat_date, show_date, region_id, registration_num registration_num FROM test01 WHERE period = 1 AND stat_date >= 20191202 AND stat_date <= 20191202) a LEFT JOIN test02 b ON a.region_id = b.id WHERE registration_num > 0 AND a.stat_date >= '20191202' AND a.stat_date <= '20191202' GROUP BY a.stat_date , a.show_date , COALESCE(b.region_name, '不详') ) JLS; id estRows task access object operator info StreamAgg_22 1.00 root funcs:count(1)->Column#22 └─HashAgg_25 1.00 root group by:Column#32, Column#33, Column#34, funcs:firstrow(1)->Column#31 └─Projection_42 0.01 root Column#14, Column#15, coalesce(test.test02.region_name, 不详)->Column#34 └─IndexJoin_28 0.01 root left outer join, inner:TableReader_27, outer key:Column#16, inner key:test.test02.id, equal cond:eq(Column#16, test.test02.id) ├─Union_33(Build) 0.01 root │ ├─Projection_34 0.00 root test.test01.stat_date, test.test01.show_date, test.test01.region_id │ │ └─TableDual_35 0.00 root rows:0 │ └─Projection_36 0.01 root test.test01.stat_date, test.test01.show_date, test.test01.region_id │ └─TableReader_39 0.01 root data:Selection_38 │ └─Selection_38 0.01 cop[tikv] eq(test.test01.period, 1), ge(test.test01.stat_date, 20191202), ge(test.test01.stat_date, 20191202), gt(cast(test.test01.registration_num), 0), le(test.test01.stat_date, 20191202), le(test.test01.stat_date, 20191202) │ └─TableFullScan_37 10000.00 cop[tikv] table:test01 keep order:false, stats:pseudo └─TableReader_27(Probe) 1.00 root data:TableRangeScan_26 └─TableRangeScan_26 1.00 cop[tikv] table:b range: decided by [Column#16], keep order:false, stats:pseudo drop table if exists t; create table t(a int, nb int not null, nc int not null); explain select ifnull(a, 0) from t; id estRows task access object operator info Projection_3 10000.00 root ifnull(test.t.a, 0)->Column#5 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select ifnull(nb, 0) from t; id estRows task access object operator info TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select ifnull(nb, 0), ifnull(nc, 0) from t; id estRows task access object operator info TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select ifnull(a, 0), ifnull(nb, 0) from t; id estRows task access object operator info Projection_3 10000.00 root ifnull(test.t.a, 0)->Column#5, test.t.nb └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select ifnull(nb, 0), ifnull(nb, 0) from t; id estRows task access object operator info Projection_3 10000.00 root test.t.nb, test.t.nb └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select 1+ifnull(nb, 0) from t; id estRows task access object operator info Projection_3 10000.00 root plus(1, test.t.nb)->Column#5 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select 1+ifnull(a, 0) from t; id estRows task access object operator info Projection_3 10000.00 root plus(1, ifnull(test.t.a, 0))->Column#5 └─TableReader_5 10000.00 root data:TableFullScan_4 └─TableFullScan_4 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select 1+ifnull(nb, 0) from t where nb=1; id estRows task access object operator info Projection_4 10.00 root plus(1, test.t.nb)->Column#5 └─TableReader_7 10.00 root data:Selection_6 └─Selection_6 10.00 cop[tikv] eq(test.t.nb, 1) └─TableFullScan_5 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select * from t ta left outer join t tb on ta.nb = tb.nb and ta.a > 1 where ifnull(ta.nb, 1) or ta.nb is null; id estRows task access object operator info HashJoin_7 8320.83 root left outer join, equal:[eq(test.t.nb, test.t.nb)], left cond:[gt(test.t.a, 1)] ├─TableReader_14(Build) 6656.67 root data:Selection_13 │ └─Selection_13 6656.67 cop[tikv] or(test.t.nb, 0) │ └─TableFullScan_12 10000.00 cop[tikv] table:tb keep order:false, stats:pseudo └─TableReader_11(Probe) 6656.67 root data:Selection_10 └─Selection_10 6656.67 cop[tikv] or(test.t.nb, 0) └─TableFullScan_9 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo explain select * from t ta right outer join t tb on ta.nb = tb.nb and ta.a > 1 where ifnull(tb.nb, 1) or tb.nb is null; id estRows task access object operator info HashJoin_7 6656.67 root right outer join, equal:[eq(test.t.nb, test.t.nb)] ├─TableReader_11(Build) 2218.89 root data:Selection_10 │ └─Selection_10 2218.89 cop[tikv] gt(test.t.a, 1), or(test.t.nb, 0) │ └─TableFullScan_9 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo └─TableReader_14(Probe) 6656.67 root data:Selection_13 └─Selection_13 6656.67 cop[tikv] or(test.t.nb, 0) └─TableFullScan_12 10000.00 cop[tikv] table:tb keep order:false, stats:pseudo explain select * from t ta inner join t tb on ta.nb = tb.nb and ta.a > 1 where ifnull(tb.nb, 1) or tb.nb is null; id estRows task access object operator info HashJoin_9 2773.61 root inner join, equal:[eq(test.t.nb, test.t.nb)] ├─TableReader_12(Build) 2218.89 root data:Selection_11 │ └─Selection_11 2218.89 cop[tikv] gt(test.t.a, 1), or(test.t.nb, 0) │ └─TableFullScan_10 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo └─TableReader_15(Probe) 6656.67 root data:Selection_14 └─Selection_14 6656.67 cop[tikv] or(test.t.nb, 0) └─TableFullScan_13 10000.00 cop[tikv] table:tb keep order:false, stats:pseudo explain select ifnull(t.nc, 1) in (select count(*) from t s , t t1 where s.a = t.a and s.a = t1.a) from t; id estRows task access object operator info Projection_12 10000.00 root Column#14 └─Apply_14 10000.00 root CARTESIAN left outer semi join, other cond:eq(test.t.nc, Column#13) ├─TableReader_16(Build) 10000.00 root data:TableFullScan_15 │ └─TableFullScan_15 10000.00 cop[tikv] table:t keep order:false, stats:pseudo └─HashAgg_19(Probe) 1.00 root funcs:count(Column#15)->Column#13 └─HashJoin_20 9.99 root inner join, equal:[eq(test.t.a, test.t.a)] ├─HashAgg_30(Build) 7.99 root group by:test.t.a, funcs:count(Column#16)->Column#15, funcs:firstrow(test.t.a)->test.t.a │ └─TableReader_31 7.99 root data:HashAgg_25 │ └─HashAgg_25 7.99 cop[tikv] group by:test.t.a, funcs:count(1)->Column#16 │ └─Selection_29 9.99 cop[tikv] eq(test.t.a, test.t.a), not(isnull(test.t.a)) │ └─TableFullScan_28 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo └─TableReader_24(Probe) 9.99 root data:Selection_23 └─Selection_23 9.99 cop[tikv] eq(test.t.a, test.t.a), not(isnull(test.t.a)) └─TableFullScan_22 10000.00 cop[tikv] table:s keep order:false, stats:pseudo explain select * from t ta left outer join t tb on ta.nb = tb.nb and ta.a > 1 where ifnull(tb.a, 1) or tb.a is null; id estRows task access object operator info Selection_7 10000.00 root or(ifnull(test.t.a, 1), isnull(test.t.a)) └─HashJoin_8 12500.00 root left outer join, equal:[eq(test.t.nb, test.t.nb)], left cond:[gt(test.t.a, 1)] ├─TableReader_13(Build) 10000.00 root data:TableFullScan_12 │ └─TableFullScan_12 10000.00 cop[tikv] table:tb keep order:false, stats:pseudo └─TableReader_11(Probe) 10000.00 root data:TableFullScan_10 └─TableFullScan_10 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo explain select * from t ta right outer join t tb on ta.nb = tb.nb and ta.a > 1 where ifnull(tb.a, 1) or tb.a is null; id estRows task access object operator info HashJoin_7 8000.00 root right outer join, equal:[eq(test.t.nb, test.t.nb)] ├─TableReader_11(Build) 3333.33 root data:Selection_10 │ └─Selection_10 3333.33 cop[tikv] gt(test.t.a, 1) │ └─TableFullScan_9 10000.00 cop[tikv] table:ta keep order:false, stats:pseudo └─TableReader_14(Probe) 8000.00 root data:Selection_13 └─Selection_13 8000.00 cop[tikv] or(ifnull(test.t.a, 1), isnull(test.t.a)) └─TableFullScan_12 10000.00 cop[tikv] table:tb keep order:false, stats:pseudo explain select ifnull(t.a, 1) in (select count(*) from t s , t t1 where s.a = t.a and s.a = t1.a) from t; id estRows task access object operator info Projection_12 10000.00 root Column#14 └─Apply_14 10000.00 root CARTESIAN left outer semi join, other cond:eq(ifnull(test.t.a, 1), Column#13) ├─TableReader_16(Build) 10000.00 root data:TableFullScan_15 │ └─TableFullScan_15 10000.00 cop[tikv] table:t keep order:false, stats:pseudo └─HashAgg_19(Probe) 1.00 root funcs:count(Column#15)->Column#13 └─HashJoin_20 9.99 root inner join, equal:[eq(test.t.a, test.t.a)] ├─HashAgg_30(Build) 7.99 root group by:test.t.a, funcs:count(Column#16)->Column#15, funcs:firstrow(test.t.a)->test.t.a │ └─TableReader_31 7.99 root data:HashAgg_25 │ └─HashAgg_25 7.99 cop[tikv] group by:test.t.a, funcs:count(1)->Column#16 │ └─Selection_29 9.99 cop[tikv] eq(test.t.a, test.t.a), not(isnull(test.t.a)) │ └─TableFullScan_28 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo └─TableReader_24(Probe) 9.99 root data:Selection_23 └─Selection_23 9.99 cop[tikv] eq(test.t.a, test.t.a), not(isnull(test.t.a)) └─TableFullScan_22 10000.00 cop[tikv] table:s keep order:false, stats:pseudo drop table if exists t; create table t(a int); explain select * from t where _tidb_rowid = 0; id estRows task access object operator info Point_Get_1 1.00 root table:t handle:0 explain select * from t where _tidb_rowid > 0; id estRows task access object operator info Projection_4 8000.00 root test.t.a └─TableReader_6 10000.00 root data:TableRangeScan_5 └─TableRangeScan_5 10000.00 cop[tikv] table:t range:(0,+inf], keep order:false, stats:pseudo explain select a, _tidb_rowid from t where a > 0; id estRows task access object operator info TableReader_7 3333.33 root data:Selection_6 └─Selection_6 3333.33 cop[tikv] gt(test.t.a, 0) └─TableFullScan_5 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select * from t where _tidb_rowid > 0 and a > 0; id estRows task access object operator info Projection_4 2666.67 root test.t.a └─TableReader_7 2666.67 root data:Selection_6 └─Selection_6 2666.67 cop[tikv] gt(test.t.a, 0) └─TableRangeScan_5 3333.33 cop[tikv] table:t range:(0,+inf], keep order:false, stats:pseudo drop table if exists t; create table t(a int, b int, c int); explain select * from (select * from t order by (select 2)) t order by a, b; id estRows task access object operator info Sort_12 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_18 10000.00 root data:TableFullScan_17 └─TableFullScan_17 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select * from (select * from t order by c) t order by a, b; id estRows task access object operator info Sort_6 10000.00 root test.t.a:asc, test.t.b:asc └─Sort_9 10000.00 root test.t.c:asc └─TableReader_12 10000.00 root data:TableFullScan_11 └─TableFullScan_11 10000.00 cop[tikv] table:t keep order:false, stats:pseudo drop table if exists t; set @@session.tidb_opt_insubq_to_join_and_agg=1; explain SELECT 0 AS a FROM dual UNION SELECT 1 AS a FROM dual ORDER BY a; id estRows task access object operator info Sort_13 2.00 root Column#3:asc └─HashAgg_17 2.00 root group by:Column#3, funcs:firstrow(Column#6)->Column#3 └─Union_18 2.00 root ├─HashAgg_19 1.00 root group by:1, funcs:firstrow(0)->Column#6, funcs:firstrow(0)->Column#3 │ └─TableDual_22 1.00 root rows:1 └─HashAgg_25 1.00 root group by:1, funcs:firstrow(1)->Column#6, funcs:firstrow(1)->Column#3 └─TableDual_28 1.00 root rows:1 explain SELECT 0 AS a FROM dual UNION (SELECT 1 AS a FROM dual ORDER BY a); id estRows task access object operator info HashAgg_15 2.00 root group by:Column#3, funcs:firstrow(Column#6)->Column#3 └─Union_16 2.00 root ├─HashAgg_17 1.00 root group by:1, funcs:firstrow(0)->Column#6, funcs:firstrow(0)->Column#3 │ └─TableDual_20 1.00 root rows:1 └─StreamAgg_27 1.00 root group by:Column#1, funcs:firstrow(Column#1)->Column#6, funcs:firstrow(Column#1)->Column#3 └─Projection_32 1.00 root 1->Column#1 └─TableDual_33 1.00 root rows:1 create table t (i int key, j int, unique key (i, j)); begin; insert into t values (1, 1); explain update t set j = -j where i = 1 and j = 1; id estRows task access object operator info Update_2 N/A root N/A └─Point_Get_1 1.00 root table:t, index:i(i, j) rollback; drop table if exists t; create table t(a int); begin; insert into t values (1); explain select * from t left outer join t t1 on t.a = t1.a where t.a not between 1 and 2; id estRows task access object operator info HashJoin_9 8320.83 root left outer join, equal:[eq(test.t.a, test.t.a)] ├─UnionScan_15(Build) 6656.67 root not(and(ge(test.t.a, 1), le(test.t.a, 2))), not(isnull(test.t.a)) │ └─TableReader_18 6656.67 root data:Selection_17 │ └─Selection_17 6656.67 cop[tikv] not(isnull(test.t.a)), or(lt(test.t.a, 1), gt(test.t.a, 2)) │ └─TableFullScan_16 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo └─UnionScan_11(Probe) 6656.67 root not(and(ge(test.t.a, 1), le(test.t.a, 2))) └─TableReader_14 6656.67 root data:Selection_13 └─Selection_13 6656.67 cop[tikv] or(lt(test.t.a, 1), gt(test.t.a, 2)) └─TableFullScan_12 10000.00 cop[tikv] table:t keep order:false, stats:pseudo rollback; drop table if exists t; create table t(a time, b date); insert into t values (1, "1000-01-01"), (2, "1000-01-02"), (3, "1000-01-03"); analyze table t; explain select * from t where a = 1; id estRows task access object operator info TableReader_7 1.00 root data:Selection_6 └─Selection_6 1.00 cop[tikv] eq(test.t.a, 00:00:01.000000) └─TableFullScan_5 3.00 cop[tikv] table:t keep order:false explain select * from t where b = "1000-01-01"; id estRows task access object operator info TableReader_7 1.00 root data:Selection_6 └─Selection_6 1.00 cop[tikv] eq(test.t.b, 1000-01-01 00:00:00.000000) └─TableFullScan_5 3.00 cop[tikv] table:t keep order:false drop table t; create table t(a int); insert into t values (1),(2),(2),(2),(9),(9),(9),(10); analyze table t with 1 buckets; explain select * from t where a >= 3 and a <= 8; id estRows task access object operator info TableReader_7 0.00 root data:Selection_6 └─Selection_6 0.00 cop[tikv] ge(test.t.a, 3), le(test.t.a, 8) └─TableFullScan_5 8.00 cop[tikv] table:t keep order:false drop table t; create table t(a int, b int, index idx_ab(a, b)); explain select a, b from t where a in (1) order by b; id estRows task access object operator info IndexReader_12 10.00 root index:IndexRangeScan_11 └─IndexRangeScan_11 10.00 cop[tikv] table:t, index:idx_ab(a, b) range:[1,1], keep order:true, stats:pseudo explain select a, b from t where a = 1 order by b; id estRows task access object operator info IndexReader_12 10.00 root index:IndexRangeScan_11 └─IndexRangeScan_11 10.00 cop[tikv] table:t, index:idx_ab(a, b) range:[1,1], keep order:true, stats:pseudo drop table if exists t; create table t(a int, b int); explain select a, b from (select a, b, avg(b) over (partition by a)as avg_b from t) as tt where a > 10 and b < 10 and a > avg_b; id estRows task access object operator info Projection_8 2666.67 root test.t.a, test.t.b └─Selection_9 2666.67 root gt(cast(test.t.a), Column#5), lt(test.t.b, 10) └─Window_10 3333.33 root avg(cast(test.t.b, decimal(65,4) BINARY))->Column#5 over(partition by test.t.a) └─Sort_14 3333.33 root test.t.a:asc └─TableReader_13 3333.33 root data:Selection_12 └─Selection_12 3333.33 cop[tikv] gt(test.t.a, 10) └─TableFullScan_11 10000.00 cop[tikv] table:t keep order:false, stats:pseudo drop table if exists t; create table t(a int, b int); explain format="dot" select * from t where a < 2; dot contents digraph TableReader_7 { subgraph cluster7{ node [style=filled, color=lightgrey] color=black label = "root" "TableReader_7" } subgraph cluster6{ node [style=filled, color=lightgrey] color=black label = "cop" "Selection_6" -> "TableFullScan_5" } "TableReader_7" -> "Selection_6" } drop table if exists t; create table t(a binary(16) not null, b varchar(2) default null, c varchar(100) default 'aaaa', key (a,b)); explain select * from t where a=x'FA34E1093CB428485734E3917F000000' and b='xb'; id estRows task access object operator info IndexLookUp_10 0.10 root ├─IndexRangeScan_8(Build) 0.10 cop[tikv] table:t, index:a(a, b) range:["[250 52 225 9 60 180 40 72 87 52 227 145 127 0 0 0]" "xb","[250 52 225 9 60 180 40 72 87 52 227 145 127 0 0 0]" "xb"], keep order:false, stats:pseudo └─TableRowIDScan_9(Probe) 0.10 cop[tikv] table:t keep order:false, stats:pseudo explain update t set c = 'ssss' where a=x'FA34E1093CB428485734E3917F000000' and b='xb'; id estRows task access object operator info Update_4 N/A root N/A └─IndexLookUp_11 0.10 root ├─IndexRangeScan_9(Build) 0.10 cop[tikv] table:t, index:a(a, b) range:["[250 52 225 9 60 180 40 72 87 52 227 145 127 0 0 0]" "xb","[250 52 225 9 60 180 40 72 87 52 227 145 127 0 0 0]" "xb"], keep order:false, stats:pseudo └─TableRowIDScan_10(Probe) 0.10 cop[tikv] table:t keep order:false, stats:pseudo drop table if exists t;