Catalog stored procedure (CSPs) are specially recognized commands that return catalog information. Client applications use CSPs instead of SQL to access information contained in the system catalog of the target database. The access service library implements CSPs by executing stored procedures against the target catalog.

When you invoke a CSP, the access service executes a stored procedure that returns a result set. It attempts to match the results an Adaptive Server would return under the same circumstances. Because the ODBC catalog is significantly different from the Adaptive Server catalog, an exact match is impossible. To make the results match, the access service performs additional computations as the rows are returned.

Because some information is static, sp_datatype_info uses memory tables to improve the speed of operation.