Messages table fixes to improve query performance (#2026)

* Move to yaml sqlc config

* Add util for ungraceful sql execs

* Fix messages schema + add indexes

* Add migration to drop+recreate messages table

* Create index only if does not exist

* Fix typo

* Unexport function

core/data/migrations.go

@@ -29,6 +29,8 @@ func migrateDatabaseSchema(db *sql.DB, from, to int) error {
 			migrateToSchema4(db)
 		case 4:
 			migrateToSchema5(db)
+		case 5:
+			migrateToSchema6(db)
 		default:
 			log.Fatalln("missing database migration step")
 		}
@@ -42,6 +44,16 @@ func migrateDatabaseSchema(db *sql.DB, from, to int) error {
 	return nil
 }
 
+func migrateToSchema6(db *sql.DB) {
+	// Fix chat messages table schema. Since chat is ephemeral we can drop
+	// the table and recreate it.
+	// Drop the old messages table
+	mustExec(`DROP TABLE messages`, db)
+
+	// Recreate it
+	CreateMessagesTable(db)
+}
+
 // nolint:cyclop
 func migrateToSchema5(db *sql.DB) {
 	// Create the access tokens table.