postgres: use CTE and GENERATED version number instead of serialized transaction (#3408)

* postgres: use CTE and GENERATED version number instead of serialized transaction

* update server version

* fix indexing CIDRs

pkg/storage/postgres/migrate.go

@@ -77,6 +77,41 @@ var migrations = []func(context.Context, pgx.Tx) error{
 			return err
 		}
 
+		return nil
+	},
+	2: func(ctx context.Context, tx pgx.Tx) error {
+		serverVersion := uint64(cryptutil.NewRandomUInt32())
+		_, err := tx.Exec(ctx, `
+			UPDATE `+schemaName+`.`+migrationInfoTableName+`
+			SET server_version = $1
+		`, serverVersion)
+		if err != nil {
+			return err
+		}
+
+		_, err = tx.Exec(ctx, `
+			DELETE FROM `+schemaName+`.`+recordChangesTableName+`
+		`)
+		if err != nil {
+			return err
+		}
+
+		_, err = tx.Exec(ctx, `
+			DELETE FROM `+schemaName+`.`+recordsTableName+`
+		`)
+		if err != nil {
+			return err
+		}
+
+		_, err = tx.Exec(ctx, `
+			ALTER TABLE `+schemaName+`.`+recordChangesTableName+`
+			ALTER COLUMN version
+			ADD GENERATED BY DEFAULT AS IDENTITY
+		`)
+		if err != nil {
+			return err
+		}
+
 		return nil
 	},
 }