Add Join Predicate Pushdown in CTE to improve the performance and reduce OOM in TiDB #28163
Description
Enhancement
The VIEW PUSHED PREDICATE operation is a specific kind of predicate pushing, the join predicate pushdown transformation, which means "The view thus becomes correlated and must be evaluated for each row of the outer query block".
The idea behind that transformation is that the view may need to be executed more frequently, but adding the join predicate to the view can make it run much faster, since the tables in that view can now use an index access.
TiDB has implemented this kind of predicate pushing for SQL written with in-line view. For example:
perfdata>explain
-> select distinct n.id olap_summary_log_id,
-> n.benchmark_id,
-> n.query_name,
-> n.plan_digest,
-> b.plan_digest baseline_plan_digest,
-> n.plan,
-> b.plan baseline_plan
-> from (
-> select s.benchmark_id,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from baseline_olap_summary_logs s,
-> baseline_olap_detail_logs d
-> where s.id = d.baseline_olap_summary_log_id
-> ) b
-> right outer join (
-> select s.id,
-> b.id benchmark_id,
-> b.name benchmark_name,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from olap_summary_logs s,
-> olap_detail_logs d,
-> benchmarks b
-> where s.id = d.olap_summary_log_id
-> and s.benchmark_id = b.id
-> ) n on b.benchmark_id = n.benchmark_id
-> and b.query_name = n.query_name
-> and n.plan_digest <> b.plan_digest
-> where n.id = 420015
-> and n.query_name = '10C';
+--------------------------------------------+---------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | estRows | task | access object | operator info |
+--------------------------------------------+---------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| HashAgg_21 | 1.00 | root | | group by:perfdata.baseline_olap_detail_logs.plan, perfdata.baseline_olap_detail_logs.plan_digest, perfdata.benchmarks.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.olap_summary_logs.id)->perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.benchmarks.id)->perfdata.benchmarks.id, funcs:firstrow(perfdata.olap_detail_logs.name)->perfdata.olap_detail_logs.name, funcs:firstrow(perfdata.olap_detail_logs.plan_digest)->perfdata.olap_detail_logs.plan_digest, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan_digest)->perfdata.baseline_olap_detail_logs.plan_digest, funcs:firstrow(perfdata.olap_detail_logs.plan)->perfdata.olap_detail_logs.plan, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan)->perfdata.baseline_olap_detail_logs.plan |
| └─HashJoin_23 | 0.00 | root | | right outer join, equal:[eq(perfdata.baseline_olap_summary_logs.benchmark_id, perfdata.benchmarks.id) eq(perfdata.baseline_olap_detail_logs.name, perfdata.olap_detail_logs.name)], other cond:ne(perfdata.olap_detail_logs.plan_digest, perfdata.baseline_olap_detail_logs.plan_digest) |
| ├─Projection_40(Build) | 0.00 | root | | perfdata.olap_summary_logs.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.benchmarks.id |
| │ └─HashJoin_42 | 0.00 | root | | CARTESIAN inner join |
| │ ├─IndexLookUp_49(Build) | 0.00 | root | | |
| │ │ ├─IndexRangeScan_46(Build) | 0.00 | cop[tikv] | table:d, index:idx_olap_detail_logs_1(olap_summary_log_id) | range:[420015,420015], keep order:false |
| │ │ └─Selection_48(Probe) | 0.00 | cop[tikv] | | eq(perfdata.olap_detail_logs.name, "10C") |
| │ │ └─TableRowIDScan_47 | 0.00 | cop[tikv] | table:d | keep order:false |
| │ └─IndexJoin_54(Probe) | 1.25 | root | | inner join, inner:TableReader_51, outer key:perfdata.olap_summary_logs.benchmark_id, inner key:perfdata.benchmarks.id, equal cond:eq(perfdata.olap_summary_logs.benchmark_id, perfdata.benchmarks.id) |
| │ ├─Point_Get_61(Build) | 1.00 | root | table:olap_summary_logs | handle:420015 |
| │ └─TableReader_51(Probe) | 1.00 | root | | data:TableRangeScan_50 |
| │ └─TableRangeScan_50 | 1.00 | cop[tikv] | table:b | range: decided by [perfdata.olap_summary_logs.benchmark_id], keep order:false, stats:pseudo |
| └─HashJoin_34(Probe) | 9.99 | root | | inner join, equal:[eq(perfdata.baseline_olap_summary_logs.id, perfdata.baseline_olap_detail_logs.baseline_olap_summary_log_id)] |
| ├─TableReader_39(Build) | 6.00 | root | | data:TableFullScan_38 |
| │ └─TableFullScan_38 | 6.00 | cop[tikv] | table:s | keep order:false, stats:pseudo |
| └─TableReader_37(Probe) | 7.99 | root | | data:Selection_36 |
| └─Selection_36 | 7.99 | cop[tikv] | | eq(perfdata.baseline_olap_detail_logs.name, "10C"), not(isnull(perfdata.baseline_olap_detail_logs.name)), not(isnull(perfdata.baseline_olap_detail_logs.plan_digest)) |
| └─TableFullScan_35 | 1943.00 | cop[tikv] | table:d | keep order:false |
+--------------------------------------------+---------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
18 rows in set (0.06 sec)
We can see that the predicates n.id = 420015 and n.query_name = '10C' was pushed into the two in-line views.
However, if I rewrote the SQL statement with CTE, I got the following plan and what's worse, the execution failed with OOM:
[email protected]:perfdata>explain
-> with nightly_data as(
-> select s.id,
-> b.id benchmark_id,
-> b.name benchmark_name,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from olap_summary_logs s,
-> olap_detail_logs d,
-> benchmarks b
-> where s.id = d.olap_summary_log_id
-> and s.benchmark_id = b.id
-> ),
-> baseline_data as(
-> select s.benchmark_id,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from baseline_olap_summary_logs s,
-> baseline_olap_detail_logs d
-> where s.id = d.baseline_olap_summary_log_id
-> )
-> select distinct n.id olap_summary_log_id,
-> n.benchmark_id,
-> n.query_name,
-> n.plan_digest,
-> b.plan_digest baseline_plan_digest,
-> n.plan,
-> b.plan baseline_plan
-> from baseline_data b
-> right outer join nightly_data n on b.benchmark_id = n.benchmark_id
-> and b.query_name = n.query_name
-> and n.plan_digest <> b.plan_digest
-> where n.id = 420015
-> and n.query_name = '10C';
+----------------------------------------+-----------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | estRows | task | access object | operator info |
+----------------------------------------+-----------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| HashAgg_90 | 38619.90 | root | | group by:perfdata.baseline_olap_detail_logs.plan, perfdata.baseline_olap_detail_logs.plan_digest, perfdata.benchmarks.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.olap_summary_logs.id)->perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.benchmarks.id)->perfdata.benchmarks.id, funcs:firstrow(perfdata.olap_detail_logs.name)->perfdata.olap_detail_logs.name, funcs:firstrow(perfdata.olap_detail_logs.plan_digest)->perfdata.olap_detail_logs.plan_digest, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan_digest)->perfdata.baseline_olap_detail_logs.plan_digest, funcs:firstrow(perfdata.olap_detail_logs.plan)->perfdata.olap_detail_logs.plan, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan)->perfdata.baseline_olap_detail_logs.plan |
| └─HashJoin_91 | 167216.64 | root | | right outer join, equal:[eq(perfdata.baseline_olap_summary_logs.benchmark_id, perfdata.benchmarks.id) eq(perfdata.baseline_olap_detail_logs.name, perfdata.olap_detail_logs.name)], other cond:ne(perfdata.olap_detail_logs.plan_digest, perfdata.baseline_olap_detail_logs.plan_digest) |
| ├─Selection_93(Build) | 1554.40 | root | | eq(perfdata.baseline_olap_detail_logs.name, "10C"), not(isnull(perfdata.baseline_olap_detail_logs.name)), not(isnull(perfdata.baseline_olap_detail_logs.plan_digest)), not(isnull(perfdata.baseline_olap_summary_logs.benchmark_id)) |
| │ └─CTEFullScan_94 | 1943.00 | root | CTE:b | data:CTE_1 |
| └─Selection_95(Probe) | 38619.90 | root | | eq(perfdata.olap_detail_logs.name, "10C"), eq(perfdata.olap_summary_logs.id, 420015) |
| └─CTEFullScan_96 | 48274.88 | root | CTE:n | data:CTE_0 |
| CTE_1 | 1943.00 | root | | Non-Recursive CTE |
| └─HashJoin_33(Seed Part) | 1943.00 | root | | inner join, equal:[eq(perfdata.baseline_olap_summary_logs.id, perfdata.baseline_olap_detail_logs.baseline_olap_summary_log_id)] |
| ├─TableReader_37(Build) | 6.00 | root | | data:TableFullScan_36 |
| │ └─TableFullScan_36 | 6.00 | cop[tikv] | table:s | keep order:false, stats:pseudo |
| └─TableReader_35(Probe) | 1943.00 | root | | data:TableFullScan_34 |
| └─TableFullScan_34 | 1943.00 | cop[tikv] | table:d | keep order:false |
| CTE_0 | 48274.88 | root | | Non-Recursive CTE |
| └─Projection_42(Seed Part) | 48274.88 | root | | perfdata.olap_summary_logs.id, perfdata.benchmarks.id, perfdata.benchmarks.name, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest |
| └─Projection_43 | 48274.88 | root | | perfdata.olap_summary_logs.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.benchmarks.id, perfdata.benchmarks.name |
| └─IndexHashJoin_50 | 48274.88 | root | | inner join, inner:IndexLookUp_47, outer key:perfdata.olap_summary_logs.id, inner key:perfdata.olap_detail_logs.olap_summary_log_id, equal cond:eq(perfdata.olap_summary_logs.id, perfdata.olap_detail_logs.olap_summary_log_id) |
| ├─IndexJoin_77(Build) | 448.75 | root | | inner join, inner:TableReader_74, outer key:perfdata.olap_summary_logs.benchmark_id, inner key:perfdata.benchmarks.id, equal cond:eq(perfdata.olap_summary_logs.benchmark_id, perfdata.benchmarks.id) |
| │ ├─TableReader_85(Build) | 359.00 | root | | data:TableFullScan_84 |
| │ │ └─TableFullScan_84 | 359.00 | cop[tikv] | table:s | keep order:false, stats:pseudo |
| │ └─TableReader_74(Probe) | 1.00 | root | | data:TableRangeScan_73 |
| │ └─TableRangeScan_73 | 1.00 | cop[tikv] | table:b | range: decided by [perfdata.olap_summary_logs.benchmark_id], keep order:false, stats:pseudo |
| └─IndexLookUp_47(Probe) | 107.58 | root | | |
| ├─IndexRangeScan_45(Build) | 107.58 | cop[tikv] | table:d, index:idx_olap_detail_logs_1(olap_summary_log_id) | range: decided by [eq(perfdata.olap_detail_logs.olap_summary_log_id, perfdata.olap_summary_logs.id)], keep order:false |
| └─TableRowIDScan_46(Probe) | 107.58 | cop[tikv] | table:d | keep order:false |
+----------------------------------------+-----------+-----------+------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
24 rows in set (0.05 sec)
And the expected plan should be like this:
perfdata>explain analyze
-> with nightly_data as(
-> select s.id,
-> b.id benchmark_id,
-> b.name benchmark_name,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from olap_summary_logs s,
-> olap_detail_logs d,
-> benchmarks b
-> where s.id = d.olap_summary_log_id
-> and s.benchmark_id = b.id
-> and s.id = 420015 -- summary_log_id
-> and d.name = '10C' -- query_name
-> ),
-> baseline_data as(
-> select s.benchmark_id,
-> d.name query_name,
-> d.plan,
-> d.plan_digest
-> from baseline_olap_summary_logs s,
-> baseline_olap_detail_logs d
-> where s.id = d.baseline_olap_summary_log_id
-> and d.name = '10C'
-> )
-> select distinct n.id olap_summary_log_id,
-> n.benchmark_id,
-> n.query_name,
-> n.plan_digest,
-> b.plan_digest baseline_plan_digest,
-> n.plan,
-> b.plan baseline_plan
-> from baseline_data b
-> join nightly_data n on b.benchmark_id = n.benchmark_id
-> and b.query_name = n.query_name
-> and n.plan_digest <> b.plan_digest;
+------------------------------------------+---------+---------+-----------+------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+---------+
| id | estRows | actRows | task | access object | execution info | operator info | memory | disk |
+------------------------------------------+---------+---------+-----------+------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+---------+
| HashAgg_69 | 1.00 | 24 | root | | time:104ms, loops:6, partial_worker:{wall_time:103.039863ms, concurrency:5, task_num:1, tot_wait:502.514862ms, tot_exec:1.586515ms, tot_time:504.964579ms, max:102.939455ms, p95:102.939455ms}, final_worker:{wall_time:103.983879ms, concurrency:5, task_num:5, tot_wait:514.800333ms, tot_exec:2.977676ms, tot_time:517.784399ms, max:103.969158ms, p95:103.969158ms} | group by:perfdata.baseline_olap_detail_logs.plan, perfdata.baseline_olap_detail_logs.plan_digest, perfdata.benchmarks.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.olap_summary_logs.id)->perfdata.olap_summary_logs.id, funcs:firstrow(perfdata.benchmarks.id)->perfdata.benchmarks.id, funcs:firstrow(perfdata.olap_detail_logs.name)->perfdata.olap_detail_logs.name, funcs:firstrow(perfdata.olap_detail_logs.plan_digest)->perfdata.olap_detail_logs.plan_digest, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan_digest)->perfdata.baseline_olap_detail_logs.plan_digest, funcs:firstrow(perfdata.olap_detail_logs.plan)->perfdata.olap_detail_logs.plan, funcs:firstrow(perfdata.baseline_olap_detail_logs.plan)->perfdata.baseline_olap_detail_logs.plan | 6.17 MB | N/A |
| └─Projection_70 | 0.00 | 24 | root | | time:100.5ms, loops:2, Concurrency:OFF | perfdata.baseline_olap_detail_logs.plan, perfdata.baseline_olap_detail_logs.plan_digest, perfdata.olap_summary_logs.id, perfdata.benchmarks.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest | 1.04 MB | N/A |
| └─HashJoin_72 | 0.00 | 24 | root | | time:100.5ms, loops:2, build_hash_table:{total:22.6ms, fetch:22.6ms, build:5.77µs}, probe:{concurrency:5, total:496.9ms, max:100.3ms, probe:1.24ms, fetch:495.6ms} | inner join, equal:[eq(perfdata.benchmarks.id, perfdata.baseline_olap_summary_logs.benchmark_id) eq(perfdata.olap_detail_logs.name, perfdata.baseline_olap_detail_logs.name)], other cond:ne(perfdata.olap_detail_logs.plan_digest, perfdata.baseline_olap_detail_logs.plan_digest) | 161.4 KB | 0 Bytes |
| ├─Selection_73(Build) | 0.00 | 3 | root | | time:22.5ms, loops:2 | not(isnull(perfdata.benchmarks.id)), not(isnull(perfdata.olap_detail_logs.name)), not(isnull(perfdata.olap_detail_logs.plan_digest)) | 81 KB | N/A |
| │ └─CTEFullScan_74 | 0.00 | 3 | root | CTE:n | time:22.4ms, loops:3 | data:CTE_0 | 181.9 KB | 0 Bytes |
| └─Selection_75(Probe) | 8.00 | 8 | root | | time:99.1ms, loops:2 | not(isnull(perfdata.baseline_olap_detail_logs.name)), not(isnull(perfdata.baseline_olap_detail_logs.plan_digest)), not(isnull(perfdata.baseline_olap_summary_logs.benchmark_id)) | 153.0 KB | N/A |
| └─CTEFullScan_76 | 10.00 | 8 | root | CTE:b | time:99ms, loops:3 | data:CTE_1 | 355.9 KB | 0 Bytes |
| CTE_0 | 0.00 | 3 | root | | time:22.4ms, loops:3 | Non-Recursive CTE | 181.9 KB | 0 Bytes |
| └─Projection_42(Seed Part) | 0.00 | 3 | root | | time:22.4ms, loops:2, Concurrency:OFF | perfdata.olap_summary_logs.id, perfdata.benchmarks.id, perfdata.benchmarks.name, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest | 90.9 KB | N/A |
| └─Projection_43 | 0.00 | 3 | root | | time:22.4ms, loops:2, Concurrency:OFF | perfdata.olap_summary_logs.id, perfdata.olap_detail_logs.name, perfdata.olap_detail_logs.plan, perfdata.olap_detail_logs.plan_digest, perfdata.benchmarks.id, perfdata.benchmarks.name | 90.9 KB | N/A |
| └─HashJoin_45 | 0.00 | 3 | root | | time:22.4ms, loops:2, build_hash_table:{total:22.3ms, fetch:22.3ms, build:3.23µs}, probe:{concurrency:5, total:111.3ms, max:22.3ms, probe:54µs, fetch:111.2ms} | CARTESIAN inner join | 136.9 KB | 0 Bytes |
| ├─IndexLookUp_52(Build) | 0.00 | 3 | root | | time:22.1ms, loops:2, index_task: {total_time: 1.36ms, fetch_handle: 1.35ms, build: 1.1µs, wait: 2.84µs}, table_task: {total_time: 27.6ms, num: 1, concurrency: 5} | | 101.6 KB | N/A |
| │ ├─IndexRangeScan_49(Build) | 0.00 | 232 | cop[tikv] | table:d, index:idx_olap_detail_logs_1(olap_summary_log_id) | time:1.34ms, loops:3, cop_task: {num: 1, max: 1.29ms, proc_keys: 232, rpc_num: 1, rpc_time: 1.28ms, copr_cache_hit_ratio: 0.00}, tikv_task:{time:0s, loops:4}, scan_detail: {total_process_keys: 232, total_keys: 233, rocksdb: {delete_skipped_count: 0, key_skipped_count: 232, block: {cache_hit_count: 7, read_count: 2, read_byte: 19.3 KB}}} | range:[420015,420015], keep order:false | N/A | N/A |
| │ └─Selection_51(Probe) | 0.00 | 3 | cop[tikv] | | time:20.1ms, loops:2, cop_task: {num: 1, max: 20ms, proc_keys: 232, tot_proc: 19ms, tot_wait: 1ms, rpc_num: 1, rpc_time: 20ms, copr_cache_hit_ratio: 0.00}, tikv_task:{time:19ms, loops:4}, scan_detail: {total_process_keys: 232, total_keys: 233, rocksdb: {delete_skipped_count: 0, key_skipped_count: 463, block: {cache_hit_count: 13, read_count: 108, read_byte: 639.1 KB}}} | eq(perfdata.olap_detail_logs.name, "10C") | N/A | N/A |
| │ └─TableRowIDScan_50 | 0.00 | 232 | cop[tikv] | table:d | tikv_task:{time:19ms, loops:4} | keep order:false | N/A | N/A |
| └─IndexJoin_57(Probe) | 1.25 | 1 | root | | time:10µs, loops:2, inner:{total:1.27ms, concurrency:5, task:1, construct:7.73µs, fetch:1.26ms, build:1.81µs}, probe:2.7µs | inner join, inner:TableReader_54, outer key:perfdata.olap_summary_logs.benchmark_id, inner key:perfdata.benchmarks.id, equal cond:eq(perfdata.olap_summary_logs.benchmark_id, perfdata.benchmarks.id) | 41.1 KB | N/A |
| ├─Point_Get_64(Build) | 1.00 | 1 | root | table:olap_summary_logs | time:497.3µs, loops:3, Get:{num_rpc:1, total_time:467.6µs}, scan_detail: {total_process_keys: 1, total_keys: 1, rocksdb: {delete_skipped_count: 0, key_skipped_count: 0, block: {cache_hit_count: 6, read_count: 1, read_byte: 15.0 KB}}} | handle:420015 | N/A | N/A |
| └─TableReader_54(Probe) | 1.00 | 1 | root | | time:1.22ms, loops:2, cop_task: {num: 1, max: 1.15ms, proc_keys: 1, rpc_num: 1, rpc_time: 1.14ms, copr_cache_hit_ratio: 0.00} | data:TableRangeScan_53 | N/A | N/A |
| └─TableRangeScan_53 | 1.00 | 1 | cop[tikv] | table:b | tikv_task:{time:0s, loops:1}, scan_detail: {total_process_keys: 1, total_keys: 1, rocksdb: {delete_skipped_count: 0, key_skipped_count: 0, block: {cache_hit_count: 8, read_count: 0, read_byte: 0 Bytes}}} | range: decided by [perfdata.olap_summary_logs.benchmark_id], keep order:false, stats:pseudo | N/A | N/A |
| CTE_1 | 10.00 | 8 | root | | time:99ms, loops:3 | Non-Recursive CTE | 355.9 KB | 0 Bytes |
| └─HashJoin_33(Seed Part) | 10.00 | 8 | root | | time:98.9ms, loops:2, build_hash_table:{total:190.1µs, fetch:180.7µs, build:9.42µs}, probe:{concurrency:5, total:493.5ms, max:98.8ms, probe:132.6µs, fetch:493.4ms} | inner join, equal:[eq(perfdata.baseline_olap_summary_logs.id, perfdata.baseline_olap_detail_logs.baseline_olap_summary_log_id)] | 16.5 KB | 0 Bytes |
| ├─TableReader_38(Build) | 6.00 | 6 | root | | time:30.2µs, loops:2, cop_task: {num: 1, max: 703.2µs, proc_keys: 6, rpc_num: 1, rpc_time: 693.5µs, copr_cache_hit_ratio: 0.00} | data:TableFullScan_37 | 304 Bytes | N/A |
| │ └─TableFullScan_37 | 6.00 | 6 | cop[tikv] | table:s | tikv_task:{time:0s, loops:1}, scan_detail: {total_process_keys: 6, total_keys: 7, rocksdb: {delete_skipped_count: 0, key_skipped_count: 6, block: {cache_hit_count: 6, read_count: 0, read_byte: 0 Bytes}}} | keep order:false, stats:pseudo | N/A | N/A |
| └─TableReader_36(Probe) | 8.00 | 8 | root | | time:98.7ms, loops:2, cop_task: {num: 1, max: 98.9ms, proc_keys: 1943, tot_proc: 98ms, rpc_num: 1, rpc_time: 98.9ms, copr_cache_hit_ratio: 0.00} | data:Selection_35 | 147.6 KB | N/A |
| └─Selection_35 | 8.00 | 8 | cop[tikv] | | tikv_task:{time:91ms, loops:6}, scan_detail: {total_process_keys: 1943, total_keys: 1944, rocksdb: {delete_skipped_count: 0, key_skipped_count: 3885, block: {cache_hit_count: 816, read_count: 0, read_byte: 0 Bytes}}} | eq(perfdata.baseline_olap_detail_logs.name, "10C") | N/A | N/A |
| └─TableFullScan_34 | 1943.00 | 1943 | cop[tikv] | table:d | tikv_task:{time:91ms, loops:6} | keep order:false | N/A | N/A |
+------------------------------------------+---------+---------+-----------+------------------------------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------+---------+
26 rows in set (0.17 sec)
Therefore, the Join Predicate Pushdown should be implemented for CTE to improve the performance and reduce OOM in TiDB.