Merge #80275 #95826

80275: sql: add a benchmark for large DROP DATABASE statements r=ajwerner a=ajwerner

Release note: None

95826: testlogic: deflake new_schema_changer test case r=postamar a=postamar

The expected output of a system.eventlog query was rewritten in e333a39 with more than one record but the query was missing an ORDER clause, leading to non-deterministic output. This commit fixes this by adding the missing ORDER clause.

Fixes #95825.

Release note: None

Co-authored-by: Andrew Werner <awerner32@gmail.com>
Co-authored-by: Marius Posta <marius@cockroachlabs.com>

pkg/sql/drop_test.go

@@ -1371,7 +1371,7 @@ func TestDropPhysicalTableGC(t *testing.T) {
 }
 
 func dropLargeDatabaseGeneric(
-	t *testing.T, workloadParams sqltestutils.GenerateViewBasedGraphSchemaParams, useDeclarative bool,
+	t testing.TB, workloadParams sqltestutils.GenerateViewBasedGraphSchemaParams, useDeclarative bool,
 ) {
 	// Creates a complex schema with a view based graph that nests within
 	// each other, which can lead to long DROP times specially if there
@@ -1392,6 +1392,10 @@ func dropLargeDatabaseGeneric(
 		sqlDB.Exec(t, `SET use_declarative_schema_changer=off;`)
 	}
 	startTime := timeutil.Now()
+	if b, isB := t.(*testing.B); isB {
+		b.StartTimer()
+		defer b.StopTimer()
+	}
 	sqlDB.Exec(t, `DROP DATABASE largedb;`)
 	t.Logf("Total time for drop (declarative: %t) %f",
 		useDeclarative,
@@ -1412,6 +1416,40 @@ func TestDropLargeDatabaseWithLegacySchemaChanger(t *testing.T) {
 		false)
 }
 
+// BenchmarkDropLargeDatabase adds a benchmark which runs a large database
+// drop for a connected graph of views. It can be used to compare the
+// legacy and declarative schema changer.
+//
+// TODO(ajwerner): The parameters to the generator are a little bit opaque.
+// It'd be nice to have a sense of how many views and how many total columns
+// we end up dropping.
+func BenchmarkDropLargeDatabase(b *testing.B) {
+	defer leaktest.AfterTest(b)()
+
+	for _, declarative := range []bool{false, true} {
+		for _, tables := range []int{3, 4} {
+			for _, depth := range []int{2, 3, 4, 5} {
+				for _, columns := range []int{2, 4} {
+					b.Run(fmt.Sprintf("tables=%d,columns=%d,depth=%d,declarative=%t",
+						tables, columns, depth, declarative), func(b *testing.B) {
+						for i := 0; i < b.N; i++ {
+							b.StopTimer()
+							dropLargeDatabaseGeneric(b,
+								sqltestutils.GenerateViewBasedGraphSchemaParams{
+									SchemaName:         "largedb",
+									NumTablesPerDepth:  tables,
+									NumColumnsPerTable: columns,
+									GraphDepth:         depth,
+								},
+								declarative)
+						}
+					})
+				}
+			}
+		}
+	}
+}
+
 func TestDropLargeDatabaseWithDeclarativeSchemaChanger(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 	defer log.Scope(t).Close(t)

pkg/sql/logictest/testdata/logic_test/new_schema_changer

@@ -1091,7 +1091,8 @@ DROP VIEW v1ev CASCADE;
 
 query IT
 SELECT "reportingID", info::JSONB - 'Timestamp' - 'DescriptorID'
-FROM system.eventlog;
+FROM system.eventlog
+ORDER BY "timestamp", info DESC
 ----
 1  {"CascadeDroppedViews": ["test.public.v4ev"], "EventType": "drop_view", "Statement": "DROP VIEW test.public.v1ev CASCADE", "Tag": "DROP VIEW", "User": "root", "ViewName": "test.public.v1ev"}
 1  {"EventType": "finish_schema_change", "InstanceID": 1}