For some large databases, the API function SQLColumns(), which is called to get a description of the columns in a table, sometimes takes a long time to execute. If you are experiencing such problems, you can use the API function call SQLDescribeCol() instead, which can improve performance for large databases.

To turn on this new functionality, set the A_ODBC_USE_SQLCOLUMNS configuration variable to FALSE.

The default value of this variable is TRUE, which means the interface will use the SQLColumns() API function.