Scrollable cursors

Informix®

Informix SQL and Genero BDL support scrollable cursors when you specify the SCROLL clause in the DECLARE cursor instruction:

DECLARE c1 SCROLL CURSOR FOR SELECT ...

Important:

Informix does not allow to fetch TEXT/BYTE columns with scrollable cursors. If you declare a scroll cursor with a SELECT containing TEXT/BYTE columns, Informix will produce the SQL error -611 when executing the OPEN instruction.

Oracle® MySQL and MariaDB

MySQL and MariaDB do not support scrollable cursors.

Solution

The MySQL and MariaDB database drivers emulate scrollable cursors by fetching rows in a temporary file.

Important:

With MySQL and MariadDB, is it NOT possible to use LOB columns in a scrollable cursor. If TEXT/BYTE columns are used with a scrollable cursor, the OPEN instruction will produce the SQL error -611 (as with Informix).