David Waller <daw138a-postgres(at)yahoo(dot)co(dot)uk> writes:
> I'm struggling with a database query that under some circumstances returns the error "ERROR: number of columns (2053) exceeds limit (1664)". Confusingly, though, no table is that wide.
This limit would be enforced against the output rows of any intermediate
join step. Without looking at EXPLAIN plans it's hard to say exactly
what's biting you, but it doesn't surprise me a a whole lot that joining
multiple 500-column tables would get you into trouble. I'd suggest
reconsidering your table schemas. Array columns might help.
regards, tom lane