ROWID columns


When creating a table, Informix automatically adds a ROWID integer column (applies to non-fragmented tables only).

The ROWID column is auto-filled with a unique number and can be used like a primary key to access a given row.

Note: Informix ROWID usage was a common practice in the early days of Informix 4GL programming. Today it is recommended to define all your database tables with a PRIMARY KEY to uniquely identify rows.

With Informix, the SQLCA.SQLERRD[6] register contains the ROWID of the last modified row.


Oracle® supports ROWIDs, but the data type is different from Informix ROWIDs: Oracle rowids are CHAR(18).

For example:

Since Oracle rowids are physical addresses, they cannot be used as permanent row identifiers ( After a DELETE, an INSERT statement might reuse the physical place of the deleted row, to store the new row ).


If the BDL application uses Informix ROWIDs, it is recommended that the program logic is reviewed in order to use the real primary keys instead (usually, serials which can be supported), or Oracle rowids as CHAR(18) ( Informix rowids will fit in this char data type).

If you cannot avoid using rowids, you must change the type of variables which hold ROWID values. Instead of using INTEGER, you must use CHAR(18). Informix rowids (integers) will automatically fit into a CHAR(18) variable.

All references to SQLCA.SQLERRD[6] must be removed because this variable will not contain the ROWID of the last modified row when using the Oracle interface.

The ROWID keyword translation can be controlled with the following FGLPROFILE entry:
dbi.database.dsname.ifxemul.rowid = { true | false }
For more details see IBM Informix emulation parameters in FGLPROFILE.