Thanks for your inputs. Reworked patch is attached.
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Regards, Rafia Sabih
CYBERTEC PostgreSQL International GmbH
You've addressed all my concerns, aside from the desire for the check on the set/update of the value. Do you have a commitfest entry? I didn't find one.
I've added myself as a reviewer. Did you want to try adding the check at time of the option being set? If not, I can make an attempt at that.
Please find the attached file for the patch with the warning message at the time of batch_size option addition. Looking forward to your inputs.
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Regards, Rafia Sabih
CYBERTEC PostgreSQL International GmbH
Applies clean, passes.
I think we need to tweak the elog() below:
+ if (batch_size > PQ_QUERY_PARAM_MAX_LIMIT) + elog(WARNING, "postgres_fdw: batch_size %d is at or above the libpq " + "%d-parameter limit; the effective per-batch ceiling is " + "limit / number_of_columns and may be lower", + batch_size, PQ_QUERY_PARAM_MAX_LIMIT);
I think this should be an ereport() because it's the sort of error we'd want the caller to see, and that means we need the message to conform the guidelines at https://www.postgresql.org/docs/current/error-style-guide.html, and I'm going to suggest this as a starting point:
ereport(WARNING,
errmsg("%s of %d exceeds protocol limit of %d", "batch_size", batch_size, PQ_QUERY_PARAM_MAX_LIMIT),
errdetail("The %s for a query will be reduced to protocol limit divided by the number of columns in the query.", "batch_size"));
I'd like to hear other people's opinions on what the proper conforming error message would be.
