Thanks for personally replying, Tom. I appreciate it. You are correct. In the interim, I found the following change solved the issue:
SPI_finish(); // move to here SRF_RETURN_DONE(funcctx); I'll look into tuplestore. Thanks for the hint. Fixed IMMUTABLE. Regards Ian Campbell On Thu, Sep 22, 2016 at 9:29 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > Ian Campbell <ianr...@gmail.com> writes: > > The function works fine on first call, sometimes more, then either resets > > the connection or throws this on any further calls: > > ERROR: cache lookup failed for type 0 SQL state: XX000 > > I think the core problem here is that you're dealing with > pass-by-reference results from the SPI_execute() --- specifically, > the int4[] "vals" values --- as if they were pass-by-value. You're > just saving the Datums, which are only pointers, and expecting what > they point to to still be good when you get around to doing > heap_form_tuple with them. But in reality they stopped being good > the moment you did SPI_finish(). > > The failures would be a lot less intermittent if you were testing in > a debug build (with CLOBBER_FREED_MEMORY defined). > > The two basic approaches you could take that would work reliably are > > 1. Copy all the int4[] values into the multi_call_memory_ctx before > doing SPI_finish. > > 2. Instead of using multi-call mode, form all the result tuples during > a single call and return them in a tuplestore, so that all the work > is done before you call SPI_finish. You wouldn't really need the FIFO > data structure if you did it that way. > > There are some other things I could criticize here, like labeling the > function IMMUTABLE when its results depend on table contents, but > they probably aren't causing your crashes. > > regards, tom lane >
