derive index filters for mv index paths

[time-and-fate]

Enhancement

Currently, there will be no index filters for mv index paths. All filters will be put on the TableRowIDScan.

create table t (a int, b varchar(30), c float, j json, pk int primary key,key mvi1(c, (cast(j->'$.a' as unsigned array)), b),key mvi2(a, (cast(j->'$.c' as unsigned array))),key mvi3((cast(j->'$.d' as unsigned array)), c),key idx(b, c));

EXPLAIN format = brief SELECT /*+ use_index_merge(t, mvi1) */ * from t where c = 1 and json_overlaps(j->'$.a', '[4,5,6]') and b not like '%test%';

> EXPLAIN format = brief SELECT /*+ use_index_merge(t, mvi1) */ * from t where
    -> c = 1 and
    -> json_overlaps(j->'$.a', '[4,5,6]') and
    -> b not like '%test%';
+-------------------------------+---------+-----------+----------------------------------------------------------------------------------+----------------------------------------------------------------------------+
| id                            | estRows | task      | access object                                                                    | operator info                                                              |
+-------------------------------+---------+-----------+----------------------------------------------------------------------------------+----------------------------------------------------------------------------+
| Selection                     | 0.24    | root      |                                                                                  | json_overlaps(json_extract(test.t.j, "$.a"), cast("[4,5,6]", json BINARY)) |
| └─IndexMerge                  | 0.30    | root      |                                                                                  | type: union                                                                |
|   ├─IndexRangeScan(Build)     | 0.10    | cop[tikv] | table:t, index:mvi1(c, cast(json_extract(`j`, _utf8'$.a') as unsigned array), b) | range:[1 4,1 4], keep order:false, stats:pseudo                            |
|   ├─IndexRangeScan(Build)     | 0.10    | cop[tikv] | table:t, index:mvi1(c, cast(json_extract(`j`, _utf8'$.a') as unsigned array), b) | range:[1 5,1 5], keep order:false, stats:pseudo                            |
|   ├─IndexRangeScan(Build)     | 0.10    | cop[tikv] | table:t, index:mvi1(c, cast(json_extract(`j`, _utf8'$.a') as unsigned array), b) | range:[1 6,1 6], keep order:false, stats:pseudo                            |
|   └─Selection(Probe)          | 0.30    | cop[tikv] |                                                                                  | not(like(test.t.b, "%test%", 92))                                          |
|     └─TableRowIDScan          | 0.30    | cop[tikv] | table:t                                                                          | keep order:false, stats:pseudo                                             |
+-------------------------------+---------+-----------+----------------------------------------------------------------------------------+----------------------------------------------------------------------------+
7 rows in set, 1 warning (0.006 sec)