fixup

Author: qw4990

expression/builtin_compare.go

@@ -15,7 +15,6 @@
 package expression
 
 import (
-	"github.com/pkg/errors"
 	"math"
 	"strings"
 
@@ -29,6 +28,7 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/collate"
 	"github.com/pingcap/tipb/go-tipb"
+	"github.com/pkg/errors"
 )
 
 var (

planner/core/plan_cache.go

@@ -278,7 +278,7 @@ func generateNewPlan(ctx context.Context, sctx sessionctx.Context, isNonPrepared
 
 	// We only cache the tableDual plan when the number of parameters are zero.
 	if containTableDual(p) && paramNum > 0 {
-		stmtCtx.SetSkipPlanCache(errors.New("cannot cache TableDual"))
+		stmtCtx.SetSkipPlanCache(errors.New("skip plan-cache: get a TableDual plan"))
 	}
 	if stmtAst.UseCache && !stmtCtx.SkipPlanCache && !ignorePlanCache {
 		// rebuild key to exclude kv.TiFlash when stmt is not read only

sessionctx/stmtctx/stmtctx.go

@@ -611,8 +611,8 @@ func (sc *StatementContext) SetPlanHint(hint string) {
 
 // SetSkipPlanCache sets to skip the plan cache and records the reason.
 func (sc *StatementContext) SetSkipPlanCache(reason error) {
-	if sc.SkipPlanCache {
-		return
+	if sc.UseCache && sc.SkipPlanCache {
+		return // avoid unnecessary warnings
 	}
 	sc.SkipPlanCache = true
 	sc.AppendWarning(reason)