public TDatabaseSchema getDatabaseSchemaByName(final String database)
      throws DatabaseNotExistsException {
    if (!isDatabaseExist(database)) {
      throw new DatabaseNotExistsException(database);
    }
    return clusterSchemaInfo.getMatchedDatabaseSchemaByName(database);
  }
Only leader use this interface. Get the specified Database's schemaengine

@param database DatabaseName
@return The specific DatabaseSchema
@throws DatabaseNotExistsException When the specific Database doesn't exist
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/schema/ClusterSchemaManager.java