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planner: avoid using index_merge when there are multiple table filters (#22122)

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This commit is contained in:
HuaiyuXu
2020-12-31 13:39:49 +08:00
committed by GitHub
parent dad3b5e87d
commit f1805f3dee
4 changed files with 72 additions and 7 deletions
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48
planner/core/integration_test.go
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@ -1429,13 +1429,10 @@ func (s *testIntegrationSerialSuite) TestIndexMerge(c *C) {
tk.MustQuery("show warnings").Check(testkit.Rows())
tk.MustQuery("desc select /*+ use_index_merge(t) */ * from t where (a=1 and length(b)=1) or (b=1 and length(a)=1)").Check(testkit.Rows(
"Projection_4 1.60 root test.t.a, test.t.b",
"└─IndexMerge_9 1.60 root ",
" ├─IndexRangeScan_5(Build) 1.00 cop[tikv] table:t, index:a(a) range:[1,1], keep order:false, stats:pseudo",
" ├─IndexRangeScan_6(Build) 1.00 cop[tikv] table:t, index:b(b) range:[1,1], keep order:false, stats:pseudo",
" └─Selection_8(Probe) 1.60 cop[tikv] eq(length(cast(test.t.a)), 1), eq(length(cast(test.t.b)), 1)",
" └─TableRowIDScan_7 2.00 cop[tikv] table:t keep order:false, stats:pseudo"))
tk.MustQuery("show warnings").Check(testkit.Rows())
"TableReader_7 1.60 root data:Selection_6",
"└─Selection_6 1.60 cop[tikv] or(and(eq(test.t.a, 1), eq(length(cast(test.t.b)), 1)), and(eq(test.t.b, 1), eq(length(cast(test.t.a)), 1)))",
" └─TableFullScan_5 10000.00 cop[tikv] table:t keep order:false, stats:pseudo"))
tk.MustQuery("show warnings").Check(testkit.Rows("Warning 1105 IndexMerge is inapplicable or disabled"))
}
func (s *testIntegrationSerialSuite) TestIssue16407(c *C) {
@ -2358,3 +2355,40 @@ func (s *testIntegrationSuite) TestIssue22040(c *C) {
c.Assert(errors.Cause(err), FitsTypeOf, expression.ErrOperandColumns)
}
}
func (s *testIntegrationSuite) TestIssue22105(c *C) {
tk := testkit.NewTestKit(c, s.store)
tk.MustExec("use test")
tk.MustExec("drop table if exists t")
tk.MustExec(`CREATE TABLE t1 (
key1 int(11) NOT NULL,
key2 int(11) NOT NULL,
key3 int(11) NOT NULL,
key4 int(11) NOT NULL,
key5 int(11) DEFAULT NULL,
key6 int(11) DEFAULT NULL,
key7 int(11) NOT NULL,
key8 int(11) NOT NULL,
KEY i1 (key1),
KEY i2 (key2),
KEY i3 (key3),
KEY i4 (key4),
KEY i5 (key5),
KEY i6 (key6)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin`)
var input []string
var output []struct {
SQL string
Plan []string
}
s.testData.GetTestCases(c, &input, &output)
for i, tt := range input {
s.testData.OnRecord(func() {
output[i].SQL = tt
output[i].Plan = s.testData.ConvertRowsToStrings(tk.MustQuery(tt).Rows())
})
tk.MustQuery(tt).Check(testkit.Rows(output[i].Plan...))
}
}

10
planner/core/stats.go
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@ -426,6 +426,9 @@ func (ds *DataSource) generateIndexMergeOrPaths() {
}
if len(partialPaths) > 1 {
possiblePath := ds.buildIndexMergeOrPath(partialPaths, i)
if possiblePath == nil {
return
}
accessConds := make([]expression.Expression, 0, len(partialPaths))
for _, p := range partialPaths {
@ -554,8 +557,15 @@ func (ds *DataSource) buildIndexMergeOrPath(partialPaths []*util.AccessPath, cur
indexMergePath := &util.AccessPath{PartialIndexPaths: partialPaths}
indexMergePath.TableFilters = append(indexMergePath.TableFilters, ds.pushedDownConds[:current]...)
indexMergePath.TableFilters = append(indexMergePath.TableFilters, ds.pushedDownConds[current+1:]...)
tableFilterCnt := 0
for _, path := range partialPaths {
// IndexMerge should not be used when the SQL is like 'select x from t WHERE (key1=1 AND key2=2) OR (key1=4 AND key3=6);'.
// Check issue https://github.com/pingcap/tidb/issues/22105 for details.
if len(path.TableFilters) > 0 {
tableFilterCnt++
if tableFilterCnt > 1 {
return nil
}
indexMergePath.TableFilters = append(indexMergePath.TableFilters, path.TableFilters...)
}
}

6
planner/core/testdata/integration_suite_in.json vendored
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@ -242,5 +242,11 @@
"explain select * from t2 where a >= 2.5 and a <= 2.5 order by b limit 2",
"explain select * from t3 where a >= 'a' and a <= 'a' and b = 'b' and c > 'c'"
]
},
{
"name": "TestIssue22105",
"cases": [
"explain SELECT /*+ use_index_merge(t1)*/ COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6)"
]
}
]

15
planner/core/testdata/integration_suite_out.json vendored
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@ -1348,5 +1348,20 @@
]
}
]
},
{
"Name": "TestIssue22105",
"Cases": [
{
"SQL": "explain SELECT /*+ use_index_merge(t1)*/ COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6)",
"Plan": [
"StreamAgg_20 1.00 root funcs:count(Column#12)->Column#10",
"└─TableReader_21 1.00 root data:StreamAgg_9",
" └─StreamAgg_9 1.00 cop[tikv] funcs:count(1)->Column#12",
" └─Selection_19 10.00 cop[tikv] or(and(eq(test.t1.key4, 42), not(isnull(test.t1.key6))), and(eq(test.t1.key1, 4), eq(test.t1.key3, 6)))",
" └─TableFullScan_18 10000.00 cop[tikv] table:t1 keep order:false, stats:pseudo"
]
}
]
}
]