use test; drop table if exists t; create table t (a int, b int, c timestamp, index idx(a)); set @@tidb_enable_window_function = 1; set @@session.tidb_window_concurrency = 1; explain select sum(a) over() from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over() └─IndexReader_12 10000.00 root index:IndexFullScan_11 └─IndexFullScan_11 10000.00 cop[tikv] table:t, index:idx(a) keep order:false, stats:pseudo explain select sum(a) over(partition by a) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a) └─IndexReader_10 10000.00 root index:IndexFullScan_9 └─IndexFullScan_9 10000.00 cop[tikv] table:t, index:idx(a) keep order:true, stats:pseudo explain select sum(a) over(partition by a order by b) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc range between unbounded preceding and current row) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b rows unbounded preceding) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc rows between unbounded preceding and current row) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b rows between 1 preceding and 1 following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc rows between 1 preceding and 1 following) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b range between 1 preceding and 1 following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc range between 1 preceding and 1 following) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by c range between interval '2:30' minute_second preceding and interval '2:30' minute_second following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.c asc range between interval "2:30" "MINUTE_SECOND" preceding and interval "2:30" "MINUTE_SECOND" following) └─Sort_11 10000.00 root test.t.a:asc, test.t.c:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo set @@session.tidb_window_concurrency = 4; explain select sum(a) over() from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over() └─IndexReader_12 10000.00 root index:IndexFullScan_11 └─IndexFullScan_11 10000.00 cop[tikv] table:t, index:idx(a) keep order:false, stats:pseudo explain select sum(a) over(partition by a) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a) └─IndexReader_10 10000.00 root index:IndexFullScan_9 └─IndexFullScan_9 10000.00 cop[tikv] table:t, index:idx(a) keep order:true, stats:pseudo explain select sum(a) over(partition by a order by b) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Shuffle_12 10000.00 root execution info: concurrency:4, data source:TableReader_10 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc range between unbounded preceding and current row) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b rows unbounded preceding) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Shuffle_12 10000.00 root execution info: concurrency:4, data source:TableReader_10 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc rows between unbounded preceding and current row) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b rows between 1 preceding and 1 following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Shuffle_12 10000.00 root execution info: concurrency:4, data source:TableReader_10 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc rows between 1 preceding and 1 following) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by b range between 1 preceding and 1 following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Shuffle_12 10000.00 root execution info: concurrency:4, data source:TableReader_10 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.b asc range between 1 preceding and 1 following) └─Sort_11 10000.00 root test.t.a:asc, test.t.b:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo explain select sum(a) over(partition by a order by c range between interval '2:30' minute_second preceding and interval '2:30' minute_second following) from t; id estRows task access object operator info Projection_7 10000.00 root Column#6 └─Shuffle_12 10000.00 root execution info: concurrency:4, data source:TableReader_10 └─Window_8 10000.00 root sum(cast(test.t.a, decimal(65,0) BINARY))->Column#6 over(partition by test.t.a order by test.t.c asc range between interval "2:30" "MINUTE_SECOND" preceding and interval "2:30" "MINUTE_SECOND" following) └─Sort_11 10000.00 root test.t.a:asc, test.t.c:asc └─TableReader_10 10000.00 root data:TableFullScan_9 └─TableFullScan_9 10000.00 cop[tikv] table:t keep order:false, stats:pseudo drop table if exists t1; create table t1(a int primary key, b int); insert into t1 values(1, 1), (2, 1); analyze table t1; explain select sum(a) over(partition by b) from t1; id estRows task access object operator info Projection_7 2.00 root Column#4 └─Window_8 2.00 root sum(cast(test.t1.a, decimal(65,0) BINARY))->Column#4 over(partition by test.t1.b) └─Sort_11 2.00 root test.t1.b:asc └─TableReader_10 2.00 root data:TableFullScan_9 └─TableFullScan_9 2.00 cop[tikv] table:t1 keep order:false insert into t1 values(3, 3); analyze table t1; explain select sum(a) over(partition by b) from t1; id estRows task access object operator info Projection_7 3.00 root Column#4 └─Shuffle_12 3.00 root execution info: concurrency:2, data source:TableReader_10 └─Window_8 3.00 root sum(cast(test.t1.a, decimal(65,0) BINARY))->Column#4 over(partition by test.t1.b) └─Sort_11 3.00 root test.t1.b:asc └─TableReader_10 3.00 root data:TableFullScan_9 └─TableFullScan_9 3.00 cop[tikv] table:t1 keep order:false