executor,store/copr: fix index merge, distsql request's key ranges should be sorted

executor/distsql.go

@@ -53,6 +53,7 @@ import (
 	"github.com/pingcap/tidb/util/ranger"
 	"github.com/pingcap/tipb/go-tipb"
 	"go.uber.org/zap"
+	"golang.org/x/exp/slices"
 )
 
 var (
@@ -304,6 +305,9 @@ func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange)
 
 	e.memTracker = memory.NewTracker(e.id, -1)
 	e.memTracker.AttachTo(e.ctx.GetSessionVars().StmtCtx.MemTracker)
+	slices.SortFunc(kvRanges, func(i, j kv.KeyRange) bool {
+		return bytes.Compare(i.StartKey, j.StartKey) < 0
+	})
 	var builder distsql.RequestBuilder
 	builder.SetKeyRanges(kvRanges).
 		SetDAGRequest(e.dagPB).
@@ -612,6 +616,10 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, workCh chan<
 			}
 
 			// init kvReq, result and worker for this partition
+			// The key ranges should be ordered.
+			slices.SortFunc(kvRange, func(i, j kv.KeyRange) bool {
+				return bytes.Compare(i.StartKey, j.StartKey) < 0
+			})
 			kvReq, err := builder.SetKeyRanges(kvRange).Build()
 			if err != nil {
 				worker.syncErr(err)

executor/distsql_test.go

@@ -26,6 +26,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/pingcap/failpoint"
 	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/metrics"
@@ -581,3 +582,49 @@ func TestAdaptiveClosestRead(t *testing.T) {
 	// 2 IndexScan with cost 19/56, 2 TableReader with cost 32.5/65.
 	checkMetrics("select/* +USE_INDEX_MERGE(t) */ id from t use index(`idx_v_s1`) use index(idx_s2) where (s1 < 3 and v > 0) or s2 = 3;", 3, 1)
 }
+
+func TestCoprocessorPagingReqKeyRangeSorted(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+
+	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/store/copr/checkKeyRangeSortedForPaging", "return"))
+	defer func() {
+		require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/store/copr/checkKeyRangeSortedForPaging"))
+	}()
+
+	tk.MustExec("use test")
+	tk.MustExec("CREATE TABLE `UK_COLLATION19523` (" +
+		"`COL1` binary(1) DEFAULT NULL," +
+		"`COL2` varchar(20) COLLATE utf8_general_ci DEFAULT NULL," +
+		"`COL4` datetime DEFAULT NULL," +
+		"`COL3` bigint(20) DEFAULT NULL," +
+		"`COL5` float DEFAULT NULL," +
+		"UNIQUE KEY `U_COL1` (`COL1`)" +
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci")
+
+	tk.MustExec("prepare stmt from 'SELECT/*+ HASH_JOIN(t1, t2) */ * FROM UK_COLLATION19523 t1 JOIN UK_COLLATION19523 t2 ON t1.col1 > t2.col1 WHERE t1.col1 IN (?, ?, ?) AND t2.col1 < ?;';")
+	tk.MustExec("set @a=0x4F, @b=0xF8, @c=NULL, @d=0xBF;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+	tk.MustExec("set @a=0x00, @b=0xD2, @c=9179987834981541375, @d=0xF8;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+
+	tk.MustExec("CREATE TABLE `IDT_COLLATION26873` (" +
+		"`COL1` varbinary(20) DEFAULT NULL," +
+		"`COL2` varchar(20) COLLATE utf8_general_ci DEFAULT NULL," +
+		"`COL4` datetime DEFAULT NULL," +
+		"`COL3` bigint(20) DEFAULT NULL," +
+		"`COL5` float DEFAULT NULL," +
+		"KEY `U_COL1` (`COL1`))")
+	tk.MustExec("prepare stmt from 'SELECT/*+ INL_JOIN(t1, t2) */ t2.* FROM IDT_COLLATION26873 t1 LEFT JOIN IDT_COLLATION26873 t2 ON t1.col1 = t2.col1 WHERE t1.col1 < ? AND t1.col1 IN (?, ?, ?);';")
+	tk.MustExec("set @a=NULL, @b=NULL, @c=NULL, @d=NULL;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+	tk.MustExec("set @a=0xE3253A6AC72A3A168EAF0E34A4779A947872CCCD, @b=0xD67BB26504EE152C2C356D7F6CAD897F03462963, @c=NULL, @d=0xDE735FEB375A4CF33479A39CA925470BFB229DB4;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+	tk.MustExec("set @a=2606738829406840179, @b=1468233589368287363, @c=5174008984061521089, @d=7727946571160309462;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+	tk.MustExec("set @a=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE, @b=NULL, @c=6864108002939154648, @d=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+	tk.MustExec("set @a=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE, @b=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE, @c=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE, @d=0xFCABFE6198B6323EE8A46247EDD33830453B1BDE;")
+	tk.MustExec("execute stmt using @a,@b,@c,@d;")
+}

executor/index_merge_reader.go

@@ -43,6 +43,7 @@ import (
 	"github.com/pingcap/tidb/util/ranger"
 	"github.com/pingcap/tipb/go-tipb"
 	"go.uber.org/zap"
+	"golang.org/x/exp/slices"
 )
 
 var (
@@ -324,6 +325,10 @@ func (e *IndexMergeReaderExecutor) startPartialIndexWorker(ctx context.Context,
 					}
 
 					// init kvReq and worker for this partition
+					// The key ranges should be ordered.
+					slices.SortFunc(keyRange, func(i, j kv.KeyRange) bool {
+						return bytes.Compare(i.StartKey, j.StartKey) < 0
+					})
 					kvReq, err := builder.SetKeyRanges(keyRange).Build()
 					if err != nil {
 						worker.syncErr(e.resultCh, err)

store/copr/coprocessor.go

@@ -15,6 +15,7 @@
 package copr
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"strconv"
@@ -51,6 +52,7 @@ import (
 	"github.com/tikv/client-go/v2/txnkv/txnsnapshot"
 	"github.com/tikv/client-go/v2/util"
 	"go.uber.org/zap"
+	"golang.org/x/exp/slices"
 )
 
 var coprCacheCounterEvict = tidbmetrics.DistSQLCoprCacheCounter.WithLabelValues("evict")
@@ -92,6 +94,18 @@ func (c *CopClient) Send(ctx context.Context, req *kv.Request, variables interfa
 		// coprocessor request but type is not DAG
 		req.Paging = false
 	}
+
+	failpoint.Inject("checkKeyRangeSortedForPaging", func(_ failpoint.Value) {
+		if req.Paging {
+			isSorted := slices.IsSortedFunc(req.KeyRanges, func(i, j kv.KeyRange) bool {
+				return bytes.Compare(i.StartKey, j.StartKey) < 0
+			})
+			if !isSorted {
+				logutil.BgLogger().Fatal("distsql request key range not sorted!")
+			}
+		}
+	})
+
 	ctx = context.WithValue(ctx, tikv.TxnStartKey(), req.StartTs)
 	ctx = context.WithValue(ctx, util.RequestSourceKey, req.RequestSource)
 	bo := backoff.NewBackofferWithVars(ctx, copBuildTaskMaxBackoff, vars)