public SqlDialect getSqlDialect() {
    return sqlDialect;
  }
statementIds that this client opens.<br>
For JDBC clients, each Statement instance has a statement id.<br>
For an IoTDBSession connection, each connection has a statement id.<br>
mqtt clients have no statement id.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/protocol/session/IClientSession.java