On Fri, Mar 2, 2018 at 8:27 AM, Alexander Korotkov <a.korot...@postgrespro.ru> wrote: > On Fri, Mar 2, 2018 at 12:40 AM, Nikita Glukhov <n.glu...@postgrespro.ru> > wrote: >> >> On 28.02.2018 06:55, Robert Haas wrote: >> >>> On Mon, Feb 26, 2018 at 10:34 AM, Nikita Glukhov >>> <n.glu...@postgrespro.ru> wrote: >>>> >>>> Attached 10th version of the jsonpath patches. >>>> >>>> 1. Fixed error handling in arithmetic operators. >>>> >>>> Now run-time errors in arithmetic operators are catched (added >>>> PG_TRY/PG_CATCH around operator's functions calls) and converted >>>> into >>>> Unknown values in predicates as it is required by the standard: >>> >>> I think we really need to rename PG_TRY and PG_CATCH or rethink this >>> whole interface so that people stop thinking they can use it to >>> prevent errors from being thrown. >> >> >> I understand that it is unsafe to call arbitrary function inside PG_TRY >> without >> rethrowing of caught errors in PG_CATCH, but in jsonpath only the >> following >> numeric and datetime functions with known behavior are called inside >> PG_TRY >> and only errors of category ERRCODE_DATA_EXCEPTION are caught: >> >> numeric_add() >> numeric_mul() >> numeric_div() >> numeric_mod() >> numeric_float8() >> float8in() >> float8_numeric() >> to_datetime() > > > That seems like a quite limited list of functions. What about reworking > them > providing a way of calling them without risk of exception? For example, we > can > have numeric_add_internal() function which fill given data structure with > error information instead of throwing the error. numeric_add() would be a > wrapper over numeric_add_internal(), which throws an error if corresponding > data structure is filled. In jsonpath we can call numeric_add_internal() > and > interpret errors in another way. That seems to be better than use of PG_TRY > and PG_CATCH. >
I haven't seen a response to this email. Do we need one before proceeding any further with jsonpath? cheers andrew -- Andrew Dunstan https://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services