> No, a UDF would still be needed to translate text blobs inside PSQL.
> But Firebird accepts a string for input to a blob column. Thus it is
> feasible for a trigger to parse the input as a string and use it
> with a UDF for comparison with an existing blob.

...

> I hope this clarifies rather than muddies....

I think it clarifies to the extent that FTS needs updating to provide
appropriate/specific trigger code for blob sub_type 1 fields. The
trigger code used at the moment is not appropriate, and at some point
a decision will be required as to how it is best to implement that
trigger (whether to require a UDF or whether to possibly have more
notifications happening than may otherwise be necessary).

It may be sufficient just to check NULL and whether the blob_id has
changed (compare the blob columns directly, not via udf). If the
blob_id has not changed then there is no change, if the blob_id has
changed the change may or may not be relevant/real.

I think we need to wait for Jason to make that call. In the short
term I suggest that John makes whatever change he deems appropriate to
the trigger code to get it working for the short term, and when Jason
gets back he can take a more detailed look at this issue.

PS. Just saw your post about a Firebird only solution. I am guessing
that Jason would rather stay away from a solution that is server
specific.

--
Geoff Worboys - TeamIBO
Telesis Computing