"Steven Flatt" <steven.flatt@xxxxxxxxx> writes: > It looks like Postgres does not enforce a limit on the length of an SQL > string. Great. However is there some point at which a query string becomes > ridiculously too long and affects performance? Yes, but it'll depend a whole lot on context; I'd suggest experimentation if you want to derive a number for your particular situation. For starters, whether you are on 32- or 64-bit hardware is hugely relevant. FYI, when we developed multi-row-VALUES quite a bit of thought was put into maintaining performance with lots of rows, and IIRC we saw reasonable performance up into the tens of thousands of rows (depending on how wide the rows are). Other ways of making a query long, such as lots of WHERE clauses, might send performance into the tank a lot quicker. So the short answer is it all depends. regards, tom lane PS: for the record, there is a hard limit at 1GB of query text, owing to restrictions built into palloc. But I think you'd hit other memory limits or performance bottlenecks before that one.
