opt: Add usage statistics to partition constrained scans

This PR adds telemetry information to the optimizer where partition
information is used to constrain table scans.

Work for https://github.com/cockroachlabs/registration/issues/228.

Release justification: Low risk monitoring improvement.

Release note: None

pkg/ccl/logictestccl/testdata/logic_test/partitioning_constrained_scans

@@ -186,3 +186,9 @@ select
  │    └── constraint: /1/2/3/4: [ - /'earth'/'us'/'cali') [/'earth'/'us'/'cali'/7 - /'earth'/'us'/'cali'/8] [/'earth'/'us'/e'cali\x00'/7 - /'earth'/'us'/'seatle') [/'earth'/'us'/'seatle'/7 - /'earth'/'us'/'seatle'/8] [/'earth'/'us'/e'seatle\x00'/7 - /'jupiter'/'titan'/'red spot') [/'jupiter'/'titan'/'red spot'/7 - /'jupiter'/'titan'/'red spot'/8] [/'jupiter'/'titan'/e'red spot\x00'/7 - ]
  └── filters
       └── (val > 6) AND (val < 9)
+
+# Test telemetry about this optimization works.
+query T
+SELECT feature_name FROM crdb_internal.feature_usage WHERE feature_name='sql.partitioning.partition-constrained-scan' AND usage_count > 0
+----
+sql.partitioning.partition-constrained-scan

pkg/sql/opt/exec/execbuilder/relational.go

@@ -28,6 +28,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/builtins"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/sql/sqlbase"
+	"github.com/cockroachdb/cockroach/pkg/sql/sqltelemetry"
 	"github.com/cockroachdb/cockroach/pkg/util"
 	"github.com/cockroachdb/cockroach/pkg/util/encoding"
 	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
@@ -455,6 +456,10 @@ func (b *Builder) buildScan(scan *memo.ScanExpr) (execPlan, error) {
 		rowCount = 0
 	}
 
+	if scan.PartitionConstrainedScan {
+		sqltelemetry.IncrementPartitioningCounter(sqltelemetry.PartitionConstrainedScan)
+	}
+
 	root, err := b.factory.ConstructScan(
 		tab,
 		tab.Index(scan.Index),

pkg/sql/opt/ops/relational.opt

@@ -64,6 +64,11 @@ define ScanPrivate {
 
     # Flags modify how the table is scanned, such as which index is used to scan.
     Flags ScanFlags
+
+    # PartitionConstrainedScan records whether or not we were able to use partitions
+    # to constrain the lookup spans further. This flag is used to record telemetry
+    # about how often this optimization is getting applied.
+    PartitionConstrainedScan bool
 }
 
 # VirtualScan returns a result set containing every row in a virtual table.

pkg/sql/opt/xform/custom_funcs.go

@@ -612,6 +612,8 @@ func (c *CustomFuncs) GenerateConstrainedScans(
 		newScanPrivate := *scanPrivate
 		newScanPrivate.Index = iter.indexOrdinal
 		newScanPrivate.Constraint = constraint
+		// Record whether we were able to use partitions to constrain the scan.
+		newScanPrivate.PartitionConstrainedScan = isIndexPartitioned
 
 		// If the alternate index includes the set of needed columns, then construct
 		// a new Scan operator using that index.

pkg/sql/opt/xform/testdata/rules/groupby

@@ -681,7 +681,7 @@ memo (optimized, ~5KB, required=[presentation: max:5])
 memo
 SELECT array_agg(w) FROM (SELECT * FROM kuvw ORDER BY w) GROUP BY u,v
 ----
-memo (optimized, ~5KB, required=[presentation: array_agg:5])
+memo (optimized, ~6KB, required=[presentation: array_agg:5])
  ├── G1: (project G2 G3 array_agg)
  │    └── [presentation: array_agg:5]
  │         ├── best: (project G2 G3 array_agg)
@@ -715,7 +715,7 @@ memo (optimized, ~5KB, required=[presentation: array_agg:5])
 memo
 SELECT sum(w) FROM kuvw GROUP BY u,v,w
 ----
-memo (optimized, ~5KB, required=[presentation: sum:5])
+memo (optimized, ~6KB, required=[presentation: sum:5])
  ├── G1: (project G2 G3 sum)
  │    └── [presentation: sum:5]
  │         ├── best: (project G2 G3 sum)

pkg/sql/opt/xform/testdata/rules/join

@@ -653,7 +653,7 @@ left-join (merge)
 memo
 SELECT * FROM abc JOIN xyz ON a=b
 ----
-memo (optimized, ~12KB, required=[presentation: a:1,b:2,c:3,x:5,y:6,z:7])
+memo (optimized, ~13KB, required=[presentation: a:1,b:2,c:3,x:5,y:6,z:7])
  ├── G1: (inner-join G2 G3 G4) (inner-join G3 G2 G4)
  │    └── [presentation: a:1,b:2,c:3,x:5,y:6,z:7]
  │         ├── best: (inner-join G3 G2 G4)

pkg/sql/opt/xform/testdata/rules/scan

@@ -289,7 +289,7 @@ memo (optimized, ~2KB, required=[presentation: s:4,i:2,f:3] [ordering: -4,+2])
 memo
 SELECT s, i, f FROM a WHERE s='foo' ORDER BY s DESC, i
 ----
-memo (optimized, ~5KB, required=[presentation: s:4,i:2,f:3] [ordering: +2 opt(4)])
+memo (optimized, ~6KB, required=[presentation: s:4,i:2,f:3] [ordering: +2 opt(4)])
  ├── G1: (select G2 G3) (scan a@s_idx,cols=(2-4),constrained) (index-join G4 a,cols=(2-4))
  │    ├── [presentation: s:4,i:2,f:3] [ordering: +2 opt(4)]
  │    │    ├── best: (sort G1)
@@ -367,7 +367,7 @@ memo (optimized, ~3KB, required=[presentation: d:4] [ordering: +5])
 memo
 SELECT j FROM a WHERE s = 'foo'
 ----
-memo (optimized, ~6KB, required=[presentation: j:5])
+memo (optimized, ~7KB, required=[presentation: j:5])
  ├── G1: (project G2 G3 j)
  │    └── [presentation: j:5]
  │         ├── best: (project G2 G3 j)

pkg/sql/opt/xform/testdata/rules/select

@@ -68,7 +68,7 @@ project
 memo
 SELECT k FROM a WHERE v > 1
 ----
-memo (optimized, ~5KB, required=[presentation: k:1])
+memo (optimized, ~6KB, required=[presentation: k:1])
  ├── G1: (project G2 G3 k)
  │    └── [presentation: k:1]
  │         ├── best: (project G2 G3 k)

pkg/sql/sqltelemetry/partitioning.go

@@ -16,18 +16,23 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/server/telemetry"
 )
 
-// PartitioningTelemetryType is an enum used to represent the different partitioning related operations
-// that we are recording telemetry for.
+// PartitioningTelemetryType is an enum used to represent the different
+// partitioning related operations that we are recording telemetry for.
 type PartitioningTelemetryType int
 
 const (
 	_ PartitioningTelemetryType = iota
-	// AlterAllPartitions represents an ALTER ALL PARTITIONS statement (ALTER PARTITION OF INDEX t@*)
+	// AlterAllPartitions represents an ALTER ALL PARTITIONS
+	// statement (ALTER PARTITION OF INDEX t@*)
 	AlterAllPartitions
+	// PartitionConstrainedScan represents when the optimizer was
+	// able to use partitioning to constrain a scan.
+	PartitionConstrainedScan
 )
 
 var partitioningTelemetryMap = map[PartitioningTelemetryType]string{
-	AlterAllPartitions: "alter-all-partitions",
+	AlterAllPartitions:       "alter-all-partitions",
+	PartitionConstrainedScan: "partition-constrained-scan",
 }
 
 func (p PartitioningTelemetryType) String() string {
@@ -43,7 +48,8 @@ func init() {
 	}
 }
 
-// IncrementPartitioningCounter is used to increment the telemetry counter for a particular partitioning operation.
+// IncrementPartitioningCounter is used to increment the telemetry
+// counter for a particular partitioning operation.
 func IncrementPartitioningCounter(partitioningType PartitioningTelemetryType) {
 	telemetry.Inc(partitioningTelemetryCounters[partitioningType])
 }