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infoschema: fix snapshot read bug for information_schema.tables (#55830)

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close pingcap/tidb#55827
This commit is contained in:
tiancaiamao
2024-09-04 11:32:16 +08:00
committed by GitHub
parent 2bd566026a
commit 7ea6526e44
3 changed files with 42 additions and 9 deletions
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20
pkg/infoschema/infoschema_v2.go
View File

@ -653,19 +653,23 @@ type TableItem struct {
// IterateAllTableItems is used for special performance optimization.
// Used by executor/infoschema_reader.go to handle reading from INFORMATION_SCHEMA.TABLES.
// If visit return false, stop the iterate process.
func (is *infoschemaV2) IterateAllTableItems(visit func(TableItem) bool) {
pivot, ok := is.byName.Max()
max, ok := is.byName.Max()
if !ok {
return
}
if !visit(TableItem{DBName: pivot.dbName, TableName: pivot.tableName}) {
return
}
is.byName.Descend(pivot, func(item tableItem) bool {
if pivot.dbName == item.dbName && pivot.tableName == item.tableName {
return true // skip MVCC version
var pivot *tableItem
is.byName.Descend(max, func(item tableItem) bool {
if item.schemaVersion > is.schemaMetaVersion {
// skip MVCC version, those items are not visible to the queried schema version
return true
}
pivot = item
if pivot != nil && pivot.dbName == item.dbName && pivot.tableName == item.tableName {
// skip MVCC version, this db.table has been visited already
return true
}
pivot = &item
if !item.tomb {
return visit(TableItem{DBName: item.dbName, TableName: item.tableName})
}

2
pkg/infoschema/test/infoschemav2test/BUILD.bazel
View File

@ -8,7 +8,7 @@ go_test(
"v2_test.go",
],
flaky = True,
shard_count = 10,
shard_count = 11,
deps = [
"//pkg/domain",
"//pkg/domain/infosync",

29
pkg/infoschema/test/infoschemav2test/v2_test.go
View File

@ -504,3 +504,32 @@ func TestSchemaSimpleTableInfos(t *testing.T) {
require.Equal(t, tblInfos[0].Name.L, "t2")
require.Equal(t, tblInfos[1].Name.L, "t1")
}
func TestSnapshotInfoschemaReader(t *testing.T) {
store := testkit.CreateMockStore(t)
tk := testkit.NewTestKit(t, store)
// For mocktikv, safe point is not initialized, we manually insert it for snapshot to use.
safePointName := "tikv_gc_safe_point"
safePointValue := "20160102-15:04:05 -0700"
safePointComment := "All versions after safe point can be accessed. (DO NOT EDIT)"
updateSafePoint := fmt.Sprintf(`INSERT INTO mysql.tidb VALUES ('%[1]s', '%[2]s', '%[3]s')
ON DUPLICATE KEY
UPDATE variable_value = '%[2]s', comment = '%[3]s'`, safePointName, safePointValue, safePointComment)
tk.MustExec(updateSafePoint)
tk.MustExec("create database issue55827")
tk.MustExec("use issue55827")
time1 := time.Now()
timeStr := time1.Format("2006-1-2 15:04:05.000")
tk.MustExec("create table t (id int primary key);")
tk.MustQuery("select count(*) from INFORMATION_SCHEMA.TABLES where table_schema = 'issue55827'").Check(testkit.Rows("1"))
tk.MustQuery("select count(tidb_table_id) from INFORMATION_SCHEMA.TABLES where table_schema = 'issue55827'").Check(testkit.Rows("1"))
// For issue 55827
sql := fmt.Sprintf("select count(*) from INFORMATION_SCHEMA.TABLES as of timestamp '%s' where table_schema = 'issue55827'", timeStr)
tk.MustQuery(sql).Check(testkit.Rows("0"))
sql = fmt.Sprintf("select * from INFORMATION_SCHEMA.TABLES as of timestamp '%s' where table_schema = 'issue55827'", timeStr)
tk.MustQuery(sql).Check(testkit.Rows())
}