@Override
  public void commitUpdateTable(String database, final String tableName) {
    database = PathUtils.unQualifyDatabaseName(database);
    readWriteLock.writeLock().lock();
    try {
      final TsTable newTable = preUpdateTableMap.get(database).get(tableName).getLeft();
      final TsTable oldTable =
          databaseTableMap
              .computeIfAbsent(database, k -> new ConcurrentHashMap<>())
              .put(tableName, newTable);
      if (LOGGER.isDebugEnabled()) {
        LOGGER.debug(
            "Commit-update table {}.{} successfully, {}",
            database,
            tableName,
            compareTable(oldTable, newTable));
      } else if (LOGGER.isInfoEnabled()) {
        LOGGER.info("Commit-update table {}.{} successfully.", database, tableName);
      }
      removeTableFromPreUpdateMap(database, tableName);
      version.incrementAndGet();
    } finally {
      readWriteLock.writeLock().unlock();
    }
  }
It contains all tables' latest column schema
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/table/DataNodeTableCache.java