what on earth does this mean?!?

Hi all.

Apologies to those who have seen this in the novice list already,
someone suggested here might be a better spot for my question.

Here 'tis.

I have just started getting the following message, by the ton, in my
postgres log:

   ERROR:  RelationCatalogInformation: Relation 21400 not found

I've traced it to the point that I know exactly what statement is producing
it, namely:

   select attribute_id from dictionary where name = 'USR-MP-EDO'

Note that this staement is representative - the same statement is executed
many times but with different names; each statement, regardles of the
name in it, causes exactly the same error message, including the same
number (21400). Needless to say, the job that needs doing, of which this
little select is a part, is not getting done :-(

When I execute this statement by hand in the same database, as the same user
as is executing the script (where these statements are coming from), it works
fine.

Any ideas most gratefully accepted. Mostly I'd like to know what the error
message means...

Regards, K.

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