planner: cherry-pick multi alternative framework and fts like rewrite back to fts branch | tidb-test=42c2474b6e2e1ef3430d07a1743ca7e17fd97acc tiflash=feature-fts tikv=feature-fts

.gitignore

@@ -78,3 +78,7 @@ var
 # Personal config files
 /*config.toml
 .cache
+
+# Claude Code runtime state (per-user, not part of repo)
+.claude/scheduled_tasks.lock
+.claude/settings.local.json

pkg/bindinfo/binding_auto_test.go

@@ -16,12 +16,14 @@ package bindinfo_test
 
 import (
 	"fmt"
+	"slices"
 	"strings"
 	"testing"
 
 	"github.com/pingcap/tidb/pkg/bindinfo"
 	"github.com/pingcap/tidb/pkg/parser"
 	"github.com/pingcap/tidb/pkg/parser/auth"
+	"github.com/pingcap/tidb/pkg/sessionctx/vardef"
 	"github.com/pingcap/tidb/pkg/testkit"
 	"github.com/pingcap/tidb/pkg/testkit/testdata"
 	"github.com/stretchr/testify/require"
@@ -211,6 +213,30 @@ func TestRelevantOptVarsAndFixes(t *testing.T) {
 	}
 }
 
+func TestRelevantOptVarsCorrelateSubquery(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec(`create table t1 (a int, b int, key(a))`)
+	tk.MustExec(`create table t2 (a int, b int, key(a))`)
+
+	p := parser.New()
+	sql := "select * from t1 where a in (select a from t2)"
+
+	// The alternative logical plans variable is recorded as relevant because the
+	// code path where it affects plan choice (correlate-to-Apply) was reached.
+	for _, enabled := range []string{"OFF", "ON"} {
+		tk.MustExec("set tidb_opt_enable_alternative_logical_plans = " + enabled)
+		p.Reset()
+		stmt, err := p.ParseOneStmt(sql, "", "")
+		require.NoError(t, err)
+		vars, _, err := bindinfo.RecordRelevantOptVarsAndFixes(tk.Session(), stmt)
+		require.NoError(t, err)
+		require.True(t, slices.Contains(vars, vardef.TiDBOptEnableAlternativeLogicalPlans),
+			"enabled=%s: expected %s in recorded vars %v", enabled, vardef.TiDBOptEnableAlternativeLogicalPlans, vars)
+	}
+}
+
 func TestExplainExploreAnalyze(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)

pkg/bindinfo/binding_plan_generation.go

@@ -406,6 +406,8 @@ func genPlanUnderState(sctx sessionctx.Context, stmt ast.StmtNode, state *state)
 			sctx.GetSessionVars().EnableSemiJoinRewrite = state.varValues[i].(bool)
 		case vardef.TiDBOptSelectivityFactor:
 			sctx.GetSessionVars().SelectivityFactor = state.varValues[i].(float64)
+		case vardef.TiDBOptEnableAlternativeLogicalPlans:
+			sctx.GetSessionVars().EnableAlternativeLogicalPlans = state.varValues[i].(bool)
 		default:
 			return nil, fmt.Errorf("unsupported variable %s in plan generation", varName)
 		}
@@ -507,7 +509,7 @@ func adjustVar(varName string, varVal any) (newVarVal any, err error) {
 		}
 		// increase 0.1 each step
 		return v + 0.1, nil
-	case vardef.TiDBOptPreferRangeScan, vardef.TiDBOptEnableNoDecorrelateInSelect, vardef.TiDBOptAlwaysKeepJoinKey, vardef.TiDBOptEnableSemiJoinRewrite: // flip the switch
+	case vardef.TiDBOptPreferRangeScan, vardef.TiDBOptEnableNoDecorrelateInSelect, vardef.TiDBOptAlwaysKeepJoinKey, vardef.TiDBOptEnableSemiJoinRewrite, vardef.TiDBOptEnableAlternativeLogicalPlans: // flip the switch
 		return !varVal.(bool), nil
 	}
 	return nil, fmt.Errorf("unsupported variable %s in plan generation", varName)
@@ -600,6 +602,8 @@ func getStartState(vars []string, fixes []uint64, indexHintCount int) (*state, e
 			s.varValues = append(s.varValues, vardef.DefOptSelectivityFactor)
 		case vardef.TiDBOptCartesianJoinOrderThreshold:
 			s.varValues = append(s.varValues, vardef.DefOptCartesianJoinOrderThreshold)
+		case vardef.TiDBOptEnableAlternativeLogicalPlans:
+			s.varValues = append(s.varValues, vardef.DefOptEnableAlternativeLogicalPlans)
 		default:
 			return nil, fmt.Errorf("unsupported variable %s in plan generation", varName)
 		}

pkg/ddl/ingest/BUILD.bazel

@@ -68,8 +68,11 @@ go_library(
 go_test(
     name = "ingest_internal_test",
     size = "small",
+    timeout = "short",
     srcs = ["engine_mgr_test.go"],
     embed = [":ingest"],
+    flaky = True,
+    shard_count = 32,
     deps = [
         "//pkg/lightning/backend",
         "//pkg/meta/model",
@@ -82,22 +85,24 @@ go_test(
     timeout = "moderate",
     srcs = [
         "checkpoint_test.go",
+        "engine_mgr_test.go",
         "env_test.go",
         "integration_test.go",
         "main_test.go",
         "mem_root_test.go",
     ],
+    embed = [":ingest"],
     flaky = True,
     race = "on",
     shard_count = 31,
     deps = [
-        ":ingest",
         "//pkg/config",
         "//pkg/config/kerneltype",
         "//pkg/ddl/ingest/testutil",
         "//pkg/ddl/session",
         "//pkg/ddl/testutil",
         "//pkg/errno",
+        "//pkg/lightning/backend",
         "//pkg/meta/model",
         "//pkg/testkit",
         "//pkg/testkit/testfailpoint",

pkg/dxf/importinto/BUILD.bazel

@@ -111,7 +111,7 @@ go_test(
     ],
     embed = [":importinto"],
     flaky = True,
-    shard_count = 31,
+    shard_count = 42,
     deps = [
         "//pkg/config",
         "//pkg/config/kerneltype",
@@ -144,9 +144,11 @@ go_test(
         "//pkg/objstore/storeapi",
         "//pkg/parser",
         "//pkg/parser/ast",
+        "//pkg/parser/mysql",
         "//pkg/planner/core",
         "//pkg/resourcemanager/pool/workerpool",
         "//pkg/session",
+        "//pkg/sessionctx",
         "//pkg/store",
         "//pkg/store/driver/error",
         "//pkg/store/mockstore",

pkg/dxf/importinto/conflictedkv/BUILD.bazel

@@ -50,7 +50,7 @@ go_test(
     ],
     embed = [":conflictedkv"],
     flaky = True,
-    shard_count = 6,
+    shard_count = 7,
     deps = [
         "//pkg/config/kerneltype",
         "//pkg/executor/importer",

pkg/executor/importer/BUILD.bazel

@@ -116,7 +116,7 @@ go_test(
     embed = [":importer"],
     flaky = True,
     race = "on",
-    shard_count = 35,
+    shard_count = 42,
     deps = [
         "//br/pkg/mock",
         "//br/pkg/streamhelper",

pkg/expression/BUILD.bazel

@@ -64,6 +64,7 @@ go_library(
         "expression.go",
         "extension.go",
         "fts_helper.go",
+        "fts_to_like.go",
         "function_traits.go",
         "grouping_sets.go",
         "helper.go",
@@ -199,6 +200,7 @@ go_test(
         "evaluator_test.go",
         "expr_to_pb_test.go",
         "expression_test.go",
+        "fts_to_like_test.go",
         "function_traits_test.go",
         "grouping_sets_test.go",
         "helper_test.go",

pkg/expression/builtin_fts.go

@@ -196,8 +196,10 @@ func (c *ftsMysqlMatchAgainstFunctionClass) getFunction(ctx BuildContext, args [
 
 func (b *builtinFtsMysqlMatchAgainstSig) evalReal(ctx EvalContext, row chunk.Row) (float64, bool, error) {
 	// Matching NULL returns 0.
-	if b.args[0].(*Constant).Value.IsNull() {
-		return 0, false, nil
+	// args[0] is validated to be a *Constant by getFunction; guard defensively
+	// since the sig may be reconstructed via the distsql path without that check.
+	if constArg, ok := b.args[0].(*Constant); ok && constArg.Value.IsNull() {
+		return 0, true, nil
 	}
 	// Reject executing match against in TiDB side
 	return 0, false, errors.Errorf("cannot use 'MATCH ... AGAINST' outside of fulltext index")

pkg/expression/distsql_builtin.go

@@ -1158,6 +1158,13 @@ func getSignatureByPB(ctx BuildContext, sigCode tipb.ScalarFuncSig, tp *tipb.Fie
 		f = &builtinVecL2NormSig{base}
 	case tipb.ScalarFuncSig_FTSMatchWord:
 		f = &builtinFtsMatchWordSig{base}
+	case tipb.ScalarFuncSig_FTSMatchExpression:
+		// NOTE: builtinFtsMysqlMatchAgainstSig.modifier is not serialized in the
+		// protobuf encoding because the tipb schema has no FTS metadata message.
+		// The reconstructed sig therefore uses the zero modifier value
+		// (FulltextSearchModifierNaturalLanguageMode). TiFlash must derive the
+		// search mode from other context when executing this expression.
+		f = &builtinFtsMysqlMatchAgainstSig{baseBuiltinFunc: base}
 	default:
 		e = ErrFunctionNotExists.GenWithStackByArgs("FUNCTION", sigCode)
 		return nil, e