Merge #62164

62164: sql: remove vectorize_row_count_threshold setting r=yuzefovich a=yuzefovich

This commit removes `vectorize_row_count_threshold` session variable and
the corresponding cluster setting. In 21.1 release these are set to 0 by
default, and in 21.2 release that default behavior cannot be changed.
This marks another step towards the start of deprecating the row-by-row
execution engine.

Fixes: #53893.

Release note (sql change): `sql.defaults.vectorize_row_count_threshold`
cluster setting as well as corresponding `vectorize_row_count_threshold`
session variable have been removed. From now on, CockroachDB will behave
exactly as if these were set to 0 (last default value).

Co-authored-by: Yahor Yuzefovich <[email protected]>

pkg/ccl/changefeedccl/helpers_test.go

@@ -271,7 +271,6 @@ func sinklessTest(testFn func(*testing.T, *gosql.DB, cdctest.TestFeedFactory)) f
 		// order to ensure that changefeeds work as expected with them (note
 		// that we'll still use the row-by-row engine, see #55605).
 		sqlDB.Exec(t, `SET CLUSTER SETTING sql.defaults.vectorize=on`)
-		sqlDB.Exec(t, `SET CLUSTER SETTING sql.defaults.vectorize_row_count_threshold=0`)
 		sqlDB.Exec(t, `CREATE DATABASE d`)
 
 		sink, cleanup := sqlutils.PGUrl(t, s.ServingSQLAddr(), t.Name(), url.User(security.RootUser))

pkg/ccl/importccl/exportcsv_test.go

@@ -408,7 +408,6 @@ func TestExportVectorized(t *testing.T) {
 	sqlDB := sqlutils.MakeSQLRunner(db)
 
 	sqlDB.Exec(t, `CREATE TABLE t(a INT PRIMARY KEY)`)
-	sqlDB.Exec(t, `SET vectorize_row_count_threshold=0`)
 	sqlDB.Exec(t, `EXPORT INTO CSV 'http://0.1:37957/exp_1' FROM TABLE t`)
 }
 

pkg/cmd/roachtest/tpc_utils.go

@@ -110,15 +110,3 @@ func createStatsFromTables(t *test, conn *gosql.DB, tableNames []string) {
 		}
 	}
 }
-
-// disableVectorizeRowCountThresholdHeuristic sets
-// 'vectorize_row_count_threshold' cluster setting to zero so that the test
-// would use the vectorized engine with 'vectorize=on' regardless of the
-// fact whether the stats are present or not (if we don't set it, then when
-// the stats are not present, we fallback to row-by-row engine even with
-// `vectorize=on` set).
-func disableVectorizeRowCountThresholdHeuristic(t *test, conn *gosql.DB) {
-	if _, err := conn.Exec("SET CLUSTER SETTING sql.defaults.vectorize_row_count_threshold=0"); err != nil {
-		t.Fatal(err)
-	}
-}

pkg/cmd/roachtest/tpcdsvec.go

@@ -57,7 +57,6 @@ func registerTPCDSVec(r *testRegistry) {
 
 		clusterConn := c.Conn(ctx, 1)
 		disableAutoStats(t, clusterConn)
-		disableVectorizeRowCountThresholdHeuristic(t, clusterConn)
 		t.Status("restoring TPCDS dataset for Scale Factor 1")
 		if _, err := clusterConn.Exec(
 			`RESTORE DATABASE tpcds FROM 'gs://cockroach-fixtures/workload/tpcds/scalefactor=1/backup';`,

pkg/cmd/roachtest/tpchvec.go

@@ -617,7 +617,6 @@ func runTPCHVec(
 
 	conn := c.Conn(ctx, 1)
 	disableAutoStats(t, conn)
-	disableVectorizeRowCountThresholdHeuristic(t, conn)
 	t.Status("restoring TPCH dataset for Scale Factor 1")
 	if err := loadTPCHDataset(ctx, t, c, 1 /* sf */, newMonitor(ctx, c), c.All()); err != nil {
 		t.Fatal(err)

pkg/settings/registry.go

@@ -77,6 +77,8 @@ var retiredSettings = map[string]struct{}{
 	"sql.testing.mutations.max_batch_size":  {},
 	"sql.testing.mock_contention.enabled":   {},
 	"kv.atomic_replication_changes.enabled": {},
+	// removed as of 21.2.
+	"sql.defaults.vectorize_row_count_threshold": {},
 }
 
 // register adds a setting to the registry.

pkg/sql/BUILD.bazel

@@ -283,7 +283,6 @@ go_library(
         "//pkg/sql/catalog/schemaexpr",
         "//pkg/sql/catalog/tabledesc",
         "//pkg/sql/catalog/typedesc",
-        "//pkg/sql/colexec",
         "//pkg/sql/colflow",
         "//pkg/sql/contention",
         "//pkg/sql/covering",

pkg/sql/colexec/constants.go

@@ -10,12 +10,6 @@
 
 package colexec
 
-// DefaultVectorizeRowCountThreshold denotes the default row count threshold.
-// When it is met, the vectorized execution engine will be used if possible.
-// TODO(yuzefovich): remove this together with vectorize_row_count_threshold
-// setting.
-const DefaultVectorizeRowCountThreshold = 0
-
 // VecMaxOpenFDsLimit specifies the maximum number of open file descriptors
 // that the vectorized engine can have (globally) for use of the temporary
 // storage.

pkg/sql/distsql_physical_planner.go

@@ -1323,9 +1323,6 @@ func (dsp *DistSQLPlanner) planTableReaders(
 
 		tr.Parallelize = info.parallelize
 		p.TotalEstimatedScannedRows += info.estimatedRowCount
-		if info.estimatedRowCount > p.MaxEstimatedRowCount {
-			p.MaxEstimatedRowCount = info.estimatedRowCount
-		}
 
 		corePlacement[i].NodeID = sp.Node
 		corePlacement[i].Core.TableReader = tr

pkg/sql/distsql_running.go

@@ -126,7 +126,6 @@ func (dsp *DistSQLPlanner) setupFlows(
 	flows map[roachpb.NodeID]*execinfrapb.FlowSpec,
 	recv *DistSQLReceiver,
 	localState distsql.LocalState,
-	vectorizeThresholdMet bool,
 	collectStats bool,
 ) (context.Context, flowinfra.Flow, error) {
 	thisNodeID := dsp.gatewayNodeID
@@ -155,26 +154,18 @@ func (dsp *DistSQLPlanner) setupFlows(
 	}
 
 	if vectorizeMode := evalCtx.SessionData.VectorizeMode; vectorizeMode != sessiondatapb.VectorizeOff {
-		if !vectorizeThresholdMet && vectorizeMode == sessiondatapb.VectorizeOn {
-			// Vectorization is not justified for this flow because the expected
-			// amount of data is too small and the overhead of pre-allocating data
-			// structures needed for the vectorized engine is expected to dominate
-			// the execution time.
-			setupReq.EvalContext.SessionData.VectorizeMode = sessiondatapb.VectorizeOff
-		} else {
-			// Now we determine whether the vectorized engine supports the flow
-			// specs.
-			for _, spec := range flows {
-				if err := colflow.IsSupported(vectorizeMode, spec); err != nil {
-					log.VEventf(ctx, 1, "failed to vectorize: %s", err)
-					if vectorizeMode == sessiondatapb.VectorizeExperimentalAlways {
-						return nil, nil, err
-					}
-					// Vectorization is not supported for this flow, so we override the
-					// setting.
-					setupReq.EvalContext.SessionData.VectorizeMode = sessiondatapb.VectorizeOff
-					break
+		// Now we determine whether the vectorized engine supports the flow
+		// specs.
+		for _, spec := range flows {
+			if err := colflow.IsSupported(vectorizeMode, spec); err != nil {
+				log.VEventf(ctx, 1, "failed to vectorize: %s", err)
+				if vectorizeMode == sessiondatapb.VectorizeExperimentalAlways {
+					return nil, nil, err
 				}
+				// Vectorization is not supported for this flow, so we override the
+				// setting.
+				setupReq.EvalContext.SessionData.VectorizeMode = sessiondatapb.VectorizeOff
+				break
 			}
 		}
 	}
@@ -325,16 +316,14 @@ func (dsp *DistSQLPlanner) Run(
 	recv.outputTypes = plan.GetResultTypes()
 	recv.contendedQueryMetric = dsp.distSQLSrv.Metrics.ContendedQueriesCount
 
-	vectorizedThresholdMet := plan.MaxEstimatedRowCount >= evalCtx.SessionData.VectorizeRowCountThreshold
-
 	if len(flows) == 1 {
 		// We ended up planning everything locally, regardless of whether we
 		// intended to distribute or not.
 		localState.IsLocal = true
 	}
 
 	ctx, flow, err := dsp.setupFlows(
-		ctx, evalCtx, leafInputState, flows, recv, localState, vectorizedThresholdMet, planCtx.collectExecStats,
+		ctx, evalCtx, leafInputState, flows, recv, localState, planCtx.collectExecStats,
 	)
 	if err != nil {
 		recv.SetError(err)

pkg/sql/exec_util.go

@@ -50,7 +50,6 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descs"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/hydratedtables"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/lease"
-	"github.com/cockroachdb/cockroach/pkg/sql/colexec"
 	"github.com/cockroachdb/cockroach/pkg/sql/contention"
 	"github.com/cockroachdb/cockroach/pkg/sql/distsql"
 	"github.com/cockroachdb/cockroach/pkg/sql/execinfra"
@@ -422,22 +421,6 @@ var VectorizeClusterMode = settings.RegisterEnumSetting(
 	},
 )
 
-// VectorizeRowCountThresholdClusterValue controls the cluster default for the
-// vectorize row count threshold. When it is met, the vectorized execution
-// engine will be used if possible.
-var VectorizeRowCountThresholdClusterValue = settings.RegisterIntSetting(
-	"sql.defaults.vectorize_row_count_threshold",
-	"default vectorize row count threshold",
-	colexec.DefaultVectorizeRowCountThreshold,
-	func(v int64) error {
-		if v < 0 {
-			return pgerror.Newf(pgcode.InvalidParameterValue,
-				"cannot set sql.defaults.vectorize_row_count_threshold to a negative value: %d", v)
-		}
-		return nil
-	},
-)
-
 // DistSQLClusterExecMode controls the cluster default for when DistSQL is used.
 var DistSQLClusterExecMode = settings.RegisterEnumSetting(
 	"sql.defaults.distsql",
@@ -2248,10 +2231,6 @@ func (m *sessionDataMutator) SetVectorize(val sessiondatapb.VectorizeExecMode) {
 	m.data.VectorizeMode = val
 }
 
-func (m *sessionDataMutator) SetVectorizeRowCountThreshold(val uint64) {
-	m.data.VectorizeRowCountThreshold = val
-}
-
 func (m *sessionDataMutator) SetTestingVectorizeInjectPanics(val bool) {
 	m.data.TestingVectorizeInjectPanics = val
 }

pkg/sql/explain_plan.go

@@ -85,12 +85,9 @@ func (e *explainPlanNode) startExec(params runParams) error {
 		flowCtx := newFlowCtxForExplainPurposes(planCtx, params.p, &distSQLPlanner.rpcCtx.ClusterID)
 
 		ctxSessionData := flowCtx.EvalCtx.SessionData
-		vectorizedThresholdMet := physicalPlan.MaxEstimatedRowCount >= ctxSessionData.VectorizeRowCountThreshold
 		var willVectorize bool
 		if ctxSessionData.VectorizeMode == sessiondatapb.VectorizeOff {
 			willVectorize = false
-		} else if !vectorizedThresholdMet && ctxSessionData.VectorizeMode == sessiondatapb.VectorizeOn {
-			willVectorize = false
 		} else {
 			willVectorize = true
 			for _, flow := range flows {

pkg/sql/flowinfra/flow_test.go

@@ -35,12 +35,8 @@ func BenchmarkFlowSetup(b *testing.B) {
 	defer logScope.Close(b)
 	ctx := context.Background()
 
-	st := cluster.MakeTestingClusterSettings()
-	// Set the threshold to 0 so that we can control which engine is used for
-	// the query execution via the vectorize mode.
-	sql.VectorizeRowCountThresholdClusterValue.Override(&st.SV, 0 /* v */)
 	s, conn, _ := serverutils.StartServer(b, base.TestServerArgs{
-		Settings: st,
+		Settings: cluster.MakeTestingClusterSettings(),
 	})
 	defer s.Stopper().Stop(ctx)
 

pkg/sql/logictest/logic.go

@@ -1520,14 +1520,6 @@ func (t *logicTest) newCluster(serverArgs TestServerArgs) {
 			}
 		}
 
-		// Always override the vectorize row count threshold. This runs all supported
-		// queries (relative to the mode) through the vectorized execution engine.
-		if _, err := conn.Exec(
-			"SET CLUSTER SETTING sql.defaults.vectorize_row_count_threshold = 0",
-		); err != nil {
-			t.Fatal(err)
-		}
-
 		if cfg.overrideAutoStats != "" {
 			if _, err := conn.Exec(
 				"SET CLUSTER SETTING sql.stats.automatic_collection.enabled = $1::bool", cfg.overrideAutoStats,

pkg/sql/logictest/testdata/logic_test/information_schema

@@ -3668,7 +3668,6 @@ transaction_isolation                                 serializable
 transaction_priority                                  normal
 transaction_read_only                                 off
 transaction_status                                    NoTxn
-vectorize_row_count_threshold                         0
 
 # information_schema can be used with the anonymous database.
 # It should show information across all databases.

pkg/sql/logictest/testdata/logic_test/pg_catalog

@@ -2158,7 +2158,6 @@ transaction_priority                                  normal              NULL
 transaction_read_only                                 off                 NULL      NULL        NULL        string
 transaction_status                                    NoTxn               NULL      NULL        NULL        string
 vectorize                                             on                  NULL      NULL        NULL        string
-vectorize_row_count_threshold                         0                   NULL      NULL        NULL        string
 
 query TTTTTTT colnames
 SELECT
@@ -2238,7 +2237,6 @@ transaction_priority                                  normal              NULL
 transaction_read_only                                 off                 NULL  user     NULL      off                 off
 transaction_status                                    NoTxn               NULL  user     NULL      NoTxn               NoTxn
 vectorize                                             on                  NULL  user     NULL      on                  on
-vectorize_row_count_threshold                         0                   NULL  user     NULL      0                   0
 
 query TTTTTT colnames
 SELECT name, source, min_val, max_val, sourcefile, sourceline FROM pg_catalog.pg_settings
@@ -2316,7 +2314,6 @@ transaction_priority                                  NULL    NULL     NULL
 transaction_read_only                                 NULL    NULL     NULL     NULL        NULL
 transaction_status                                    NULL    NULL     NULL     NULL        NULL
 vectorize                                             NULL    NULL     NULL     NULL        NULL
-vectorize_row_count_threshold                         NULL    NULL     NULL     NULL        NULL
 
 # pg_catalog.pg_sequence
 

pkg/sql/logictest/testdata/logic_test/show_source

@@ -95,7 +95,6 @@ transaction_priority                                  normal
 transaction_read_only                                 off
 transaction_status                                    NoTxn
 vectorize                                             on
-vectorize_row_count_threshold                         0
 
 query T colnames
 SELECT * FROM [SHOW CLUSTER SETTING sql.defaults.distsql]

pkg/sql/logictest/testdata/logic_test/system

@@ -602,7 +602,6 @@ SELECT name, value
 FROM system.settings
 WHERE name NOT IN ('version', 'sql.defaults.distsql', 'cluster.secret',
   'sql.stats.automatic_collection.enabled', 'sql.defaults.vectorize',
-  'sql.defaults.vectorize_row_count_threshold',
   'sql.defaults.experimental_distsql_planning')
 ORDER BY name
 ----