Hi hackers, I see evidence on this list that it's sort of a rite of passage to ask the flinfo->fn_extra question, and my time has come.
So please let me know if I seem to correctly understand the limits on its use. I gather that various extensions use it to stash various things. But (I assume) ... they will only touch fn_extra in FmgrInfo structs that pertain to *their own functions*. (Please say that's true?) IOW, it is assured that, if I am a language handler, when I am called to handle a function in my language, fn_extra is mine to use as I please ... ... with the one big exception, if I am handling a function in my language that returns a set, and I will use SFRM_ValuePerCall mode, I have to leave fn_extra NULL before SRF_FIRSTCALL_INIT(), which plants its own gunk there, and then I can stash my stuff in gunk->user_fctx for the duration of that SRF call. Does that seem to catch the essentials? Thanks, -Chap p.s.: noticed in fmgr/README: "Note that simple "strict" functions can ignore both isnull and args[i].isnull, since they won't even get called when there are any TRUE values in args[].isnull." I get why a strict function can ignore args[i].isnull, but is the part about ignoring isnull a mistake? A strict function can be passed all non-null arguments and still return null if it wants to, right?
