postgresql/doc
Tom Lane 913bbd88dc Improve the handling of result type coercions in SQL functions.
Use the parser's standard type coercion machinery to convert the
output column(s) of a SQL function's final SELECT or RETURNING
to the type(s) they should have according to the function's declared
result type.  We'll allow any case where an assignment-level
coercion is available.  Previously, we failed unless the required
coercion was a binary-compatible one (and the documentation ignored
this, falsely claiming that the types must match exactly).

Notably, the coercion now accounts for typmods, so that cases where
a SQL function is declared to return a composite type whose columns
are typmod-constrained now behave as one would expect.  Arguably
this aspect is a bug fix, but the overall behavioral change here
seems too large to consider back-patching.

A nice side-effect is that functions can now be inlined in a
few cases where we previously failed to do so because of type
mismatches.

Discussion: https://postgr.es/m/18929.1574895430@sss.pgh.pa.us
2020-01-08 11:07:59 -05:00
..
src Improve the handling of result type coercions in SQL functions. 2020-01-08 11:07:59 -05:00
KNOWN_BUGS Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
Makefile Remove maintainer-check target, fold into normal build 2013-10-10 20:11:56 -04:00
MISSING_FEATURES Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
TODO Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00