Because catalog functions, such as those listed here, are slow compared to other ODBC functions, their frequent use can impair system performance:
SQLColumns
SQLForeignKeys
SQLGetTypeInfo
SQLSpecialColumns
SQLStatistics
SQLTables
SQLGetTypeInfo is included in this list of expensive ODBC functions because many drivers must query the server to obtain accurate information about which types are supported (for example, to find dynamic types such as user defined types).