ttljob: fix a range edge case

Release note (bug fix): Fix a bug in row-level TTL where the last range
key of a table may overlap with a separate table or index, resulting in
a "error decoding X bytes" error message when performing row-level TTL.

pkg/sql/ttl/ttljob/ttljob.go

@@ -284,12 +284,11 @@ func (t rowLevelTTLResumer) Resume(ctx context.Context, execCtx interface{}) err
 
 	var initialVersion descpb.DescriptorVersion
 
-	// TODO(#75428): feature flag check, ttl pause check.
 	var ttlSettings catpb.RowLevelTTL
 	var pkColumns []string
 	var pkTypes []*types.T
 	var relationName string
-	var rangeSpan roachpb.Span
+	var rangeSpan, entirePKSpan roachpb.Span
 	if err := db.Txn(ctx, func(ctx context.Context, txn *kv.Txn) error {
 		desc, err := descsCol.GetImmutableTableByID(
 			ctx,
@@ -333,7 +332,8 @@ func (t rowLevelTTLResumer) Resume(ctx context.Context, execCtx interface{}) err
 		}
 
 		relationName = tn.FQString()
-		rangeSpan = desc.TableSpan(p.ExecCfg().Codec)
+		entirePKSpan = desc.IndexSpan(p.ExecCfg().Codec, desc.GetPrimaryIndex().GetID())
+		rangeSpan = entirePKSpan
 		ttlSettings = *ttl
 		return nil
 	}); err != nil {
@@ -459,15 +459,40 @@ func (t rowLevelTTLResumer) Resume(ctx context.Context, execCtx interface{}) err
 				if err := r.ValueProto(&rangeDesc); err != nil {
 					return err
 				}
-				rangeSpan.Key = rangeDesc.EndKey.AsRawKey()
 				var nextRange rangeToProcess
-				nextRange.startPK, err = keyToDatums(rangeDesc.StartKey, p.ExecCfg().Codec, pkTypes, &alloc)
-				if err != nil {
-					return errors.Wrapf(err, "error decoding starting PRIMARY KEY for range ID %d", rangeDesc.RangeID)
+				// A single range can contain multiple tables or indexes.
+				// If this is the case, the rangeDesc.StartKey would be less than entirePKSpan.Key
+				// or the rangeDesc.EndKey would be greater than the entirePKSpan.EndKey, meaning
+				// the range contains the start or the end of the range respectively.
+				// Trying to decode keys outside the PK range will lead to a decoding error.
+				// As such, only populate nextRange.startPK and nextRange.endPK if this is the case
+				// (by default, a 0 element startPK or endPK means the beginning or end).
+				if rangeDesc.StartKey.AsRawKey().Compare(entirePKSpan.Key) > 0 {
+					nextRange.startPK, err = keyToDatums(rangeDesc.StartKey, p.ExecCfg().Codec, pkTypes, &alloc)
+					if err != nil {
+						return errors.Wrapf(
+							err,
+							"error decoding starting PRIMARY KEY for range ID %d (start key %x, table start key %x)",
+							rangeDesc.RangeID,
+							rangeDesc.StartKey.AsRawKey(),
+							entirePKSpan.Key,
+						)
+					}
 				}
-				nextRange.endPK, err = keyToDatums(rangeDesc.EndKey, p.ExecCfg().Codec, pkTypes, &alloc)
-				if err != nil {
-					return errors.Wrapf(err, "error decoding ending PRIMARY KEY for range ID %d", rangeDesc.RangeID)
+				if rangeDesc.EndKey.AsRawKey().Compare(entirePKSpan.EndKey) < 0 {
+					rangeSpan.Key = rangeDesc.EndKey.AsRawKey()
+					nextRange.endPK, err = keyToDatums(rangeDesc.EndKey, p.ExecCfg().Codec, pkTypes, &alloc)
+					if err != nil {
+						return errors.Wrapf(
+							err,
+							"error decoding ending PRIMARY KEY for range ID %d (end key %x, table end key %x)",
+							rangeDesc.RangeID,
+							rangeDesc.EndKey.AsRawKey(),
+							entirePKSpan.EndKey,
+						)
+					}
+				} else {
+					done = true
 				}
 				ch <- nextRange
 			}

pkg/sql/ttl/ttljob/ttljob_test.go

@@ -301,6 +301,8 @@ func TestRowLevelTTLJobRandomEntries(t *testing.T) {
 	type testCase struct {
 		desc              string
 		createTable       string
+		preSetup          []string
+		postSetup         []string
 		numExpiredRows    int
 		numNonExpiredRows int
 		numSplits         int
@@ -316,6 +318,23 @@ func TestRowLevelTTLJobRandomEntries(t *testing.T) {
 			numExpiredRows:    1001,
 			numNonExpiredRows: 5,
 		},
+		{
+			desc: "one column pk, table ranges overlap",
+			createTable: `CREATE TABLE tbl (
+	id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+	text TEXT
+) WITH (ttl_expire_after = '30 days')`,
+			preSetup: []string{
+				`CREATE TABLE tbm (id INT PRIMARY KEY)`,
+				`ALTER TABLE tbm SPLIT AT VALUES (1)`,
+			},
+			postSetup: []string{
+				`CREATE TABLE tbl2 (id INT PRIMARY KEY)`,
+				`ALTER TABLE tbl2 SPLIT AT VALUES (1)`,
+			},
+			numExpiredRows:    1001,
+			numNonExpiredRows: 5,
+		},
 		{
 			desc: "one column pk with statistics",
 			createTable: `CREATE TABLE tbl (
@@ -388,9 +407,12 @@ func TestRowLevelTTLJobRandomEntries(t *testing.T) {
 	other_col INT,
 	"quote-kw-col" TIMESTAMPTZ,
 	text TEXT,
-	INDEX (text),
+	INDEX text_idx (text),
 	PRIMARY KEY (id, other_col, "quote-kw-col")
 ) WITH (ttl_expire_after = '30 days', ttl_select_batch_size = 50, ttl_delete_batch_size = 10, ttl_range_concurrency = 3)`,
+			postSetup: []string{
+				`ALTER INDEX tbl@text_idx SPLIT AT VALUES ('bob')`,
+			},
 			numExpiredRows:    1001,
 			numNonExpiredRows: 5,
 			numSplits:         10,
@@ -440,6 +462,11 @@ func TestRowLevelTTLJobRandomEntries(t *testing.T) {
 			rangeBatchSize := 1 + rng.Intn(3)
 			t.Logf("range batch size: %d", rangeBatchSize)
 
+			for _, stmt := range tc.preSetup {
+				t.Logf("running pre statement: %s", stmt)
+				th.sqlDB.Exec(t, stmt)
+			}
+
 			th.sqlDB.Exec(t, tc.createTable)
 			th.sqlDB.Exec(t, `SET CLUSTER SETTING sql.ttl.range_batch_size = $1`, rangeBatchSize)
 
@@ -529,6 +556,11 @@ func TestRowLevelTTLJobRandomEntries(t *testing.T) {
 				addRow(timeutil.Now().Add(time.Hour * 24 * 30))
 			}
 
+			for _, stmt := range tc.postSetup {
+				t.Logf("running post statement: %s", stmt)
+				th.sqlDB.Exec(t, stmt)
+			}
+
 			// Force the schedule to execute.
 			th.env.SetTime(timeutil.Now().Add(time.Hour * 24))
 			require.NoError(t, th.executeSchedules())