Data Retrieval on SEQ
When opening sequential files, Uniface attempts to establish both read and write access. If this fails, Uniface opens them with read-only access. Users can read data, but any attempt to update the data causes the appropriate warning or error message to be returned.
Because SEQ is based on system-dependent I/O
calls, it is not possible for the connector to distinguish between
violation of read-only access and any other I/O error.
If users have read-only access and they try to write to a sequential
file, inappropriate messages can result, including bad file number
, or occurrence no longer exists
. Remember that there is no locking
available at any time; sequential files should be used by single
users only. You should take these limitations into account when using the SEQ connector in a production environment.
The retrieveSequential trigger is not supported.