docs: public void openLog(Database db) {
  
          needsCheckpoint = false;
  
          String path = db.getPath();
          int loglevel = db.getProperties().getIntegerProperty(
              HsqlDatabaseProperties.hsqldb_applog, 0);
  
          this.database = db;
  
          if (loglevel != SimpleLog.LOG_NONE) {
              appLog = new SimpleLog(path + ".app.log", loglevel,
                                     !db.isFilesReadOnly());
          }
  
          appLog.sendLine(SimpleLog.LOG_ERROR, "Database (re)opened");
  
          logStatements = false;
  
          boolean useLock = db.getProperties().isPropertyTrue(
              HsqlDatabaseProperties.hsqldb_lock_file);
  
          if (useLock && !db.isFilesReadOnly()) {
              acquireLock(path);
          }
  
          log = new Log(db);
  
          log.open();
  
          logsStatements = logStatements = !db.isFilesReadOnly();
      }