Optimize join tables from different databases

[ea-rus]

For the query:

select * from table1 t1
join table2 t2 on t1.id=t2.id

After getting data from t1, it is extracting unique ids from this data and uses this query to get data from second table:

select * from table2 where id in (<ids from previous step>)

Fixes: https://linear.app/mindsdb/issue/BE-436/optimize-join

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mindsdb_sql
__about__.py	10	10	0%	1–10
__init__.py	129	22	83%	43, 47, 93, 110, 134–153, 160–161, 178
mindsdb_sql/parser
lexer.py	165	1	99%	243
logger.py	19	4	79%	14, 17, 23, 26
parser.py	460	31	93%	48, 53, 73, 77, 81, 87, 91–93, 121–128, 182, 199, 249, 253, 317, 346–347, 367, 378, 491, 526, 557, 567, 581, 662
utils.py	46	4	91%	73–79
mindsdb_sql/parser/ast
base.py	36	7	81%	13, 28, 31, 49–52
create.py	76	10	87%	7–8, 23, 28, 91–96
drop.py	52	2	96%	10, 13
insert.py	63	4	94%	39–41, 46
show.py	48	1	98%	18
update.py	53	5	91%	40–42, 75–76
mindsdb_sql/parser/ast/select
case.py	32	2	94%	19, 22
constant.py	36	1	97%	23
data.py	11	2	82%	15, 19
identifier.py	64	7	89%	43, 80–85
native_query.py	13	1	92%	25
operation.py	131	4	97%	56, 65, 168, 187
parameter.py	11	1	91%	10
select.py	97	3	97%	148–153
star.py	12	2	83%	8–9
union.py	23	1	96%	18
mindsdb_sql/parser/dialects/mindsdb
knowledge_base.py	46	1	98%	79
lexer.py	262	21	92%	343, 345, 347, 359, 361, 363, 369–387
parser.py	1027	26	97%	118, 122, 261, 286, 383, 569, 586, 610–611, 807, 861, 938, 1065, 1075, 1113–1114, 1143, 1154, 1236, 1299, 1360, 1844, 1852, 1905–1908
mindsdb_sql/parser/dialects/mysql
lexer.py	23	6	74%	16, 18, 20, 32, 34, 36
parser.py	613	24	96%	131, 133, 226–227, 326, 356, 373, 423, 427, 501, 511, 549–550, 570, 581, 702, 730, 735–737, 741, 758, 907, 1051
show_index.py	17	11	35%	10–12, 15–23, 26–27
mindsdb_sql/planner
plan_join.py	370	17	95%	144, 152, 186, 195, 222, 226, 315, 365, 383, 395–396, 447, 475, 481, 498, 521, 523
plan_join_ts.py	179	10	94%	53, 60, 83–84, 129, 181, 185, 193, 268, 335
query_plan.py	22	8	64%	13–21, 30
query_planner.py	414	67	84%	41–42, 65–66, 75, 166, 309, 327–329, 336, 437, 465–543, 586–587, 600, 626, 691, 721, 747, 772–774
query_prepare.py	284	61	79%	76, 78, 86–116, 227, 249, 272, 315, 336, 360, 389–443, 446–452, 483, 496–498, 507, 526
step_result.py	14	2	86%	7, 12
steps.py	158	16	90%	12, 17, 25, 30–32, 51–53, 61–64, 90–92
ts_utils.py	67	6	91%	59, 61, 83–86, 90
utils.py	242	27	89%	60, 106, 112, 127, 139, 151, 154, 166, 194, 207, 222, 228, 233, 240, 242, 247, 260, 265, 271, 277, 291, 308, 338–339, 350–351, 366
mindsdb_sql/render
sqlalchemy_render.py	462	70	85%	56, 91, 93, 105, 110, 127, 129, 131, 133, 195, 212–213, 224–225, 243, 273, 275, 286, 323, 337, 343, 394, 459–463, 474–478, 508, 523, 537, 542, 555–556, 559–560, 567, 590–601, 621, 654–678, 701, 707, 747–750, 771–774
TOTAL	6645	498	93%

Tests	Skipped	Failures	Errors	Time
684	1 💤	0 ❌	0 🔥	25.311s ⏱️