sql,hints: add builtin function to add statement hint for hint "injection"

This commit adds a new builtin function for inserting "hint injection" hints
into the `system.statement_hints` table. Currently, the provided hinted SQL
is serialized as-is into the hint. A future PR will add validation to ensure
that the hinted SQL matches the fingerprint, and that the hints can be
transferred.

Informs #153633

Release note: None

Author: DrewKimball

pkg/ccl/logictestccl/tests/3node-tenant/generated_test.go

@@ -442,6 +442,7 @@ go_library(
         "//pkg/sql/faketreeeval",
         "//pkg/sql/flowinfra",
         "//pkg/sql/gcjob/gcjobnotifier",
+        "//pkg/sql/hintpb",
         "//pkg/sql/hints",
         "//pkg/sql/idxrecommendations",
         "//pkg/sql/idxusage",

pkg/ccl/logictestccl/tests/local-read-committed/generated_test.go

@@ -11,6 +11,7 @@ go_library(
         "//pkg/roachpb",
         "//pkg/security/username",
         "//pkg/sql/catalog/descpb",
+        "//pkg/sql/hintpb",
         "//pkg/sql/pgwire/pgcode",
         "//pkg/sql/pgwire/pgerror",
         "//pkg/sql/pgwire/pgnotice",

pkg/ccl/logictestccl/tests/local-repeatable-read/generated_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/security/username"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/hintpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgcode"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgerror"
 	"github.com/cockroachdb/cockroach/pkg/sql/pgwire/pgnotice"
@@ -589,6 +590,13 @@ func (ep *DummyEvalPlanner) ProcessVectorIndexFixups(
 	return nil
 }
 
+// InsertStatementHint is part of the eval.Planner interface.
+func (ep *DummyEvalPlanner) InsertStatementHint(
+	ctx context.Context, statementFingerprint string, hint hintpb.StatementHintUnion,
+) (int64, error) {
+	return 0, nil
+}
+
 // DummyPrivilegedAccessor implements the tree.PrivilegedAccessor interface by returning errors.
 type DummyPrivilegedAccessor struct{}
 

pkg/sql/BUILD.bazel

@@ -0,0 +1,94 @@
+# LogicTest: !local-mixed-25.2 !local-mixed-25.3
+
+statement ok
+CREATE TABLE xy (x INT PRIMARY KEY, y INT, INDEX (y));
+
+statement ok
+CREATE TABLE ab (a INT PRIMARY KEY, b INT, INDEX (b));
+
+query I
+SELECT count(*) FROM system.statement_hints;
+----
+0
+
+let $hint1
+SELECT crdb_internal.inject_hint(
+  'SELECT * FROM xy WHERE y = 10',
+  'SELECT * FROM xy@primary WHERE y = 10'
+);
+
+# Verify that the returned hint ID is in the table.
+query T
+SELECT fingerprint FROM system.statement_hints WHERE row_id = $hint1;
+----
+SELECT * FROM xy WHERE y = 10
+
+let $hint2
+SELECT crdb_internal.inject_hint(
+  'SELECT * FROM xy WHERE y = 10',
+  'SELECT * FROM xy@xy_y_idx WHERE y = 10'
+);
+
+# Verify that the returned hint ID is in the table.
+query T
+SELECT fingerprint FROM system.statement_hints WHERE row_id = $hint2;
+----
+SELECT * FROM xy WHERE y = 10
+
+let $hint3
+SELECT crdb_internal.inject_hint(
+  'SELECT * FROM xy INNER JOIN ab ON xy.x = ab.b',
+  'SELECT * FROM xy INNER JOIN ab ON xy.x = ab.b'
+);
+
+# Verify that the returned hint ID is in the table.
+query T
+SELECT fingerprint FROM system.statement_hints WHERE row_id = $hint3;
+----
+SELECT * FROM xy INNER JOIN ab ON xy.x = ab.b
+
+query I
+SELECT count(*) FROM system.statement_hints;
+----
+3
+
+query I
+SELECT count(*) FROM system.statement_hints WHERE fingerprint = 'SELECT * FROM xy WHERE y = 10';
+----
+2
+
+query I
+SELECT count(*) FROM system.statement_hints WHERE fingerprint = 'SELECT * FROM xy INNER JOIN ab ON xy.x = ab.b';
+----
+1
+
+statement ok
+DELETE FROM system.statement_hints WHERE true;
+
+query I
+SELECT count(*) FROM system.statement_hints;
+----
+0
+
+# If the surrounding transaction is rolled back, no hint should be inserted.
+statement ok
+BEGIN;
+
+let $hint4
+SELECT crdb_internal.inject_hint(
+  'SELECT * FROM xy WHERE y = 10',
+  'SELECT * FROM xy@{NO_FULL_SCAN} WHERE y = 10'
+);
+
+query T
+SELECT fingerprint FROM system.statement_hints WHERE row_id = $hint4;
+----
+SELECT * FROM xy WHERE y = 10
+
+statement ok
+ROLLBACK;
+
+query I
+SELECT count(*) FROM system.statement_hints;
+----
+0