planner/core: make TIDB_INLJ to specify the inner table

[zz-jason]

What problem does this PR solve?

as the title says

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test

Code changes

• Has exported function/method change

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation
• Need to be included in the release note

[zz-jason]

/run-all-tests

[winoros]

there're also tests in executor test

[zz-jason]

/run-common-test

[XuHuaiyu]

executor/index_lookup_join_test.go                                                                                                                                                                                          [8/808]
32:     rs, err := tk.Exec("select /*+ TIDB_INLJ(o, i)*/ * from idxJoinOuter o left join idxJoinInner i on o.a = i.a where o.a in (1, 2) and (i.a - 3) > 0")
50:     tk.MustQuery("explain select /*+ TIDB_INLJ(t1, t2)*/ * from t1 join t2 on t1.a = t2.id").Check(testkit.Rows(
59:     tk.MustQuery("select /*+ TIDB_INLJ(t1, t2)*/ * from t1 join t2 on t1.a = t2.id").Check(testkit.Rows(
63:     tk.MustQuery("explain select /*+ TIDB_INLJ(t1, t2)*/ * from t1 join t2 on t1.a = t2.a").Check(testkit.Rows(
73:     tk.MustQuery("select /*+ TIDB_INLJ(t1, t2)*/ * from t1 join t2 on t1.a = t2.a").Check(testkit.Rows(
78:     tk.MustQuery("explain select /*+ TIDB_INLJ(t1, t2)*/ t1.a, t2.a from t1 join t2 on t1.a = t2.a").Check(testkit.Rows(
88:     tk.MustQuery("select /*+ TIDB_INLJ(t1, t2)*/ t1.a, t2.a from t1 join t2 on t1.a = t2.a").Check(testkit.Rows(
105:    tk.MustQuery("explain select /*+ TIDB_INLJ(t1, t2)*/ count(*) from t1 join t2 on t1.a = t2.a").Check(testkit.Rows(
115:    tk.MustQuery("select /*+ TIDB_INLJ(t1, t2)*/ count(*) from t1 join t2 on t1.a = t2.id").Check(testkit.Rows(

executor/join_test.go
147:    tk.MustQuery("select /*+ TIDB_INLJ(t, t1) */ * from t join t1 on t.a=t1.a").Check(testkit.Rows("1 1 1 2", "1 1 1 3", "1 1 1 4", "3 3 3 4"))
148:    tk.MustQuery("select /*+ TIDB_INLJ(t1) */ * from t1 join t on t.a=t1.a and t.a < t1.b").Check(testkit.Rows("1 2 1 1", "1 3 1 1", "1 4 1 1", "3 4 3 3"))
150:    tk.MustQuery("select /*+ TIDB_INLJ(t, t1) */ t1.b from t1 join t on t.b=t1.b").Check(testkit.Rows("2", "3"))
151:    tk.MustQuery("select /*+ TIDB_INLJ(t, t1) */ * from t right outer join t1 on t.a=t1.a").Check(testkit.Rows("1 1 1 2", "1 1 1 3", "1 1 1 4", "3 3 3 4", "<nil> <nil> 4 5"))
152:    tk.MustQuery("select /*+ TIDB_INLJ(t, t1) */ avg(t.b) from t right outer join t1 on t.a=t1.a").Check(testkit.Rows("1.5000"))
155:    _, err = tk.Exec("select /*+ TIDB_INLJ(t) TIDB_SMJ(t) */ * from t join t1 on t.a=t1.a")
157:    _, err = tk.Exec("select /*+ TIDB_INLJ(t) TIDB_HJ(t) */ from t join t1 on t.a=t1.a")
172:    tk.MustQuery("select /*+ TIDB_INLJ(t) */ * from t join t1 on t.a=t1.a order by t.b").Check(testkit.Rows("3 1 3 4", "1 3 1 2", "1 3 1 3"))
173:    tk.MustQuery("select /*+ TIDB_INLJ(t1) */ t.a, t.b from t join t1 on t.a=t1.a where t1.b = 4 limit 1").Check(testkit.Rows("3 1"))
174:    tk.MustQuery("select /*+ TIDB_INLJ(t, t1) */ * from t right join t1 on t.a=t1.a order by t.b").Check(testkit.Rows("<nil> <nil> 0 0", "3 1 3 4", "1 3 1 2", "1 3 1 3"))
190:    tk.MustQuery("select /*+ TIDB_INLJ(t1) */ t1.a from t1, t where t.a = 5 and t.b = t1.a").Check(testkit.Rows("3"))
329:    result = tk.MustQuery("select /*+ TIDB_INLJ(t) */ * from t left join t1 on t1.c1 = t.c1")
347:    result = tk.MustQuery("select a from (select /*+ TIDB_INLJ(t1, t2) */ t1.a from t t1 join t t2 on t1.a=t2.a) t group by a")
675:    result = tk.MustQuery("select (select /*+ TIDB_INLJ(x1) */ x2.a from t1 x1, t1 x2 where x1.a = t1.a and x1.a = x2.a) from t1")
812:    tk.MustQuery("select /*+ TIDB_INLJ(t2) */ * from t1 join t2 on t1.a=t2.a").Check(testkit.Rows("1 2017-11-29 2.2 1"))
839:    tk.MustQuery("select /*+ TIDB_INLJ(t, s) */ t.a from t join s on t.a = s.a").Check(testkit.Rows("-277544960", "-277544960"))
840:    tk.MustQuery("select /*+ TIDB_INLJ(t, s) */ t.a from t left join s on t.a = s.a").Check(testkit.Rows("148307968", "-1327693824", "-277544960", "-277544960"))
841:    tk.MustQuery("select /*+ TIDB_INLJ(t, s) */ t.a from t right join s on t.a = s.a").Check(testkit.Rows("-277544960", "<nil>", "<nil>", "-277544960", "<nil>", "<nil>"))
845:    tk.MustQuery("SELECT /*+ TIDB_INLJ(t1, t2) */ * FROM t t1 JOIN t t2 ON t1.a=t2.a UNION ALL SELECT /*+ TIDB_INLJ(t1, t2) */ * FROM t t1 JOIN t t2 ON t1.a=t2.a;").Check(testkit.Rows("1 2 1 2", "1 2 1 2"))
850:    tk.MustQuery(`select /*+ TIDB_INLJ(t1) */ t1.a from t t1 join t t2 on t1.a=t2.a order by t1.a;`).Check(testkit.Rows(
859:    tk.MustQuery(`select /*+ TIDB_INLJ(t1) */ * from t t1 left join t t2 on t1.a = t2.a and t1.b = t2.b + 4;`).Check(testkit.Rows(

planner/core/logical_plan_test.go
902:                    sql:  "explain select /*+ TIDB_INLJ(t1, t2) */ * from t t1 left join t t2 on t1.a=t2.a where t1.b=1 and t2.b=1 and (t1.c=1 or t2.c=1)",

[zz-jason]

@XuHuaiyu @winoros @eurekaka PTAL

[eurekaka]

LGTM.

[eurekaka]

The motivation of this PR is because outer child may be a subquery?

[eurekaka]

/run-all-tests

[zz-jason]

@eurekaka Yes, in this situation, it's hard to force the optimizer to chose index join.

[zz-jason]

/run-integration-compatibility-test
/run-integration-ddl-test

[zz-jason]

/run-integration-ddl-test

[XuHuaiyu]

LGTM

[XuHuaiyu]

/run-common-test tidb-test=pr/641
/run-integration-common-test tidb-test=pr/641