When changing an application to use ROWID that currently uses RECID, you can complete the change with only a keyword substitution if your application does not:

Otherwise, after you change all RECID references to ROWID, you must rewrite your integer references to use character strings. If you use database or temporary tables, you must also convert the relevant fields to CHARACTER fields, and use the STRING and TO–ROWID functions to store and retrieve ROWID values. However, note that some DataServers build a string for a single ROWID that can reach up to several hundred bytes (including a complete WHERE clause).

All DataServer tables support ROWID references except those, such as views, that do not have unique row identifiers. DataServers from earlier Progress versions also support ROWID references. Progress Versions 7.3A and later use an internal RECID that transparently converts to a ROWID in the client.