EXPLAIN FOR CONNECTION does not include "access object", resulting in partition pruning is not included.

[mjonss]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

select connection_id(); -- Use this in the last step!
create table t (a int, b int, c json, primary key (a,b), key (b)) partition by range (b) (partition p0 values less than (1000000), partition pMax values less than (maxvalue));
explain analyze select a,b,c from t where b between 1 and 10;
explain for connection 1400897542; -- Use the actual connection id from above!

2. What did you expect to see? (Required)

Same output as for the direct EXPLAIN ANALYZE

3. What did you see instead (Required)

The "access object" column is empty for the first row "partition:p0"

tidb> select connection_id(); -- Use this in the last step!
+-----------------------------------------------+
| connection_id() -- Use this in the last step! |
+-----------------------------------------------+
|                                    1400897542 |
+-----------------------------------------------+
1 row in set (0.00 sec)

tidb> create table t (a int, b int, c json, primary key (a,b), key (b)) partition by range (b) (partition p0 values less than (1000000), partition pMax values less than (maxvalue));
Query OK, 0 rows affected (0.02 sec)

tidb> explain analyze select a,b,c from t where b between 1 and 10;
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+-----------+------+
| id                      | estRows  | actRows | task      | access object | execution info                                                                                                                                                                                                                                                  | operator info                     | memory    | disk |
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+-----------+------+
| TableReader_7           | 250.00   | 0       | root      | partition:p0  | time:241.7µs, loops:1, RU:0.480514, cop_task: {num: 1, max: 221µs, proc_keys: 0, tot_proc: 16.5µs, tot_wait: 51.9µs, copr_cache_hit_ratio: 0.00, build_task_duration: 2.71µs, max_distsql_concurrency: 1}, rpc_info:{Cop:{num_rpc:1, total_time:215.5µs}} | data:Selection_6                  | 231 Bytes | N/A  |
| └─Selection_6       | 250.00   | 0       | cop[tikv] |               | tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 44.2µs, rocksdb: {block: {}}}, time_detail: {total_process_time: 16.5µs, total_wait_time: 51.9µs, tikv_wall_time: 140.1µs}                                                    | ge(test.t.b, 1), le(test.t.b, 10) | N/A       | N/A  |
|   └─TableFullScan_5 | 10000.00 | 0       | cop[tikv] | table:t       | tikv_task:{time:0s, loops:1}                                                                                                                                                                                                                                    | keep order:false, stats:pseudo    | N/A       | N/A  |
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+-----------+------+
3 rows in set (0.00 sec)

tidb> explain for connection 1400897542; -- Use the actual connection id from above!
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+--------+------+
| id                      | estRows  | actRows | task      | access object | execution info                                                                                                                                                                                                                                                  | operator info                     | memory | disk |
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+--------+------+
| TableReader_7           | 250.00   | 0       | root      |               | time:241.7µs, loops:1, RU:0.480514, cop_task: {num: 1, max: 221µs, proc_keys: 0, tot_proc: 16.5µs, tot_wait: 51.9µs, copr_cache_hit_ratio: 0.00, build_task_duration: 2.71µs, max_distsql_concurrency: 1}, rpc_info:{Cop:{num_rpc:1, total_time:215.5µs}} | data:Selection_6                  | N/A    | N/A  |
| └─Selection_6       | 250.00   | 0       | cop[tikv] |               | tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 44.2µs, rocksdb: {block: {}}}, time_detail: {total_process_time: 16.5µs, total_wait_time: 51.9µs, tikv_wall_time: 140.1µs}                                                    | ge(test.t.b, 1), le(test.t.b, 10) | N/A    | N/A  |
|   └─TableFullScan_5 | 10000.00 | 0       | cop[tikv] | table:t       | tikv_task:{time:0s, loops:1}                                                                                                                                                                                                                                    | keep order:false, stats:pseudo    | N/A    | N/A  |
+-------------------------+----------+---------+-----------+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------+--------+------+
3 rows in set (0.00 sec)

4. What is your TiDB version? (Required)

tidb_version(): Release Version: v8.4.0-alpha-33-gac9916a21e
Edition: Community
Git Commit Hash: ac9916a21e7ab38c563ce7c3d6a4b134e11f978f
Git Branch: HEAD
UTC Build Time: 2024-08-26 11:58:51
GoVersion: go1.21.10
Race Enabled: false
Check Table Before Drop: false
Store: tikv