refactor

planner/core/logical_plans.go

@@ -1838,8 +1838,7 @@ type LogicalShow struct {
 	logicalSchemaProducer
 	ShowContents
 
-	Extractor    ShowPredicateExtractor
-	buildPattern bool // It depends on ShowPredicateExtractor now
+	Extractor ShowPredicateExtractor
 }
 
 // LogicalShowDDLJobs is for showing DDL job list.

planner/core/planbuilder.go

@@ -2928,10 +2928,11 @@ func (b *PlanBuilder) buildShow(ctx context.Context, show *ast.ShowStmt) (Plan,
 			GlobalScope:           show.GlobalScope,
 			Extended:              show.Extended,
 		},
-		buildPattern: true,
 	}.Init(b.ctx)
 	isView := false
 	isSequence := false
+	// It depends on ShowPredicateExtractor now
+	buildPattern := true
 
 	switch show.Tp {
 	case ast.ShowDatabases, ast.ShowVariables, ast.ShowTables, ast.ShowColumns, ast.ShowTableStatus, ast.ShowCollation:
@@ -2940,7 +2941,7 @@ func (b *PlanBuilder) buildShow(ctx context.Context, show *ast.ShowStmt) (Plan,
 		}
 		if extractor := newShowBaseExtractor(*show); extractor.Extract() {
 			p.Extractor = extractor
-			p.buildPattern = false
+			buildPattern = false
 		}
 	case ast.ShowCreateTable, ast.ShowCreateSequence, ast.ShowPlacementForTable, ast.ShowPlacementForPartition:
 		var err error
@@ -3012,7 +3013,7 @@ func (b *PlanBuilder) buildShow(ctx context.Context, show *ast.ShowStmt) (Plan,
 	var np LogicalPlan
 	np = p
 	// If we have ShowPredicateExtractor, we do not buildSelection with Pattern
-	if show.Pattern != nil && p.buildPattern {
+	if show.Pattern != nil && buildPattern {
 		show.Pattern.Expr = &ast.ColumnNameExpr{
 			Name: &ast.ColumnName{Name: p.OutputNames()[0].ColName},
 		}