perf(fields): create index for instance domain query (#9146)

# Which Problems Are Solved

get instance by domain cannot provide an instance id because it is not
known at that time. This causes a full table scan on the fields table
because current indexes always include the `instance_id` column.

# How the Problems Are Solved

Added a specific index for this query.

# Additional Context

If a system has many fields and there is no cache hit for the given
domain this query can heaviuly influence database CPU usage, the newly
added resolves this problem.

(cherry picked from commit f320d18b1a)

cmd/setup/43.go

@@ -0,0 +1,40 @@
+package setup
+
+import (
+	"context"
+	"embed"
+	"fmt"
+
+	"github.com/zitadel/logging"
+
+	"github.com/zitadel/zitadel/internal/database"
+	"github.com/zitadel/zitadel/internal/eventstore"
+)
+
+var (
+	//go:embed 43/cockroach/*.sql
+	//go:embed 43/postgres/*.sql
+	createFieldsDomainIndex embed.FS
+)
+
+type CreateFieldsDomainIndex struct {
+	dbClient *database.DB
+}
+
+func (mig *CreateFieldsDomainIndex) Execute(ctx context.Context, _ eventstore.Event) error {
+	statements, err := readStatements(createFieldsDomainIndex, "43", mig.dbClient.Type())
+	if err != nil {
+		return err
+	}
+	for _, stmt := range statements {
+		logging.WithFields("file", stmt.file, "migration", mig.String()).Info("execute statement")
+		if _, err := mig.dbClient.ExecContext(ctx, stmt.query); err != nil {
+			return fmt.Errorf("%s %s: %w", mig.String(), stmt.file, err)
+		}
+	}
+	return nil
+}
+
+func (mig *CreateFieldsDomainIndex) String() string {
+	return "43_create_fields_domain_index"
+}

cmd/setup/43/cockroach/43.sql

@@ -0,0 +1,3 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS fields_instance_domains_idx
+ON eventstore.fields (object_id)
+WHERE object_type = 'instance_domain' AND field_name = 'domain';

cmd/setup/43/postgres/43.sql

@@ -0,0 +1,3 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS fields_instance_domains_idx
+ON eventstore.fields (object_id) INCLUDE (instance_id)
+WHERE object_type = 'instance_domain' AND field_name = 'domain';

cmd/setup/config.go

@@ -127,6 +127,7 @@ type Steps struct {
 	s37Apps7OIDConfigsBackChannelLogoutURI  *Apps7OIDConfigsBackChannelLogoutURI
 	s38BackChannelLogoutNotificationStart   *BackChannelLogoutNotificationStart
 	s40InitPushFunc                         *InitPushFunc
+	s43CreateFieldsDomainIndex              *CreateFieldsDomainIndex
 }
 
 func MustNewSteps(v *viper.Viper) *Steps {

cmd/setup/setup.go

@@ -170,6 +170,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 	steps.s37Apps7OIDConfigsBackChannelLogoutURI = &Apps7OIDConfigsBackChannelLogoutURI{dbClient: esPusherDBClient}
 	steps.s38BackChannelLogoutNotificationStart = &BackChannelLogoutNotificationStart{dbClient: esPusherDBClient, esClient: eventstoreClient}
 	steps.s40InitPushFunc = &InitPushFunc{dbClient: esPusherDBClient}
+	steps.s43CreateFieldsDomainIndex = &CreateFieldsDomainIndex{dbClient: queryDBClient}
 
 	err = projection.Create(ctx, projectionDBClient, eventstoreClient, config.Projections, nil, nil, nil)
 	logging.OnError(err).Fatal("unable to start projections")
@@ -240,6 +241,7 @@ func Setup(ctx context.Context, config *Config, steps *Steps, masterKey string)
 		steps.s32AddAuthSessionID,
 		steps.s33SMSConfigs3TwilioAddVerifyServiceSid,
 		steps.s37Apps7OIDConfigsBackChannelLogoutURI,
+		steps.s43CreateFieldsDomainIndex,
 	} {
 		mustExecuteMigration(ctx, eventstoreClient, step, "migration failed")
 	}