John Lumby <johnlumby@hotmail.com> writes:
> I feel that more on this topic needs to be added to the reference information for SELECT,
> both in the description of the (expressions in the) SELECT-list and in the description of the FROM list, and in
particulara note on how and why certain usages are equivalent when written in specific ways, (and maybe even which is
preferred).
> Currently there is a thorough description of the semantics of [ LATERAL ] ROWS FROM in the FROM list, but very
littleabout the effect of placing one or more what set-returning functions in the SELECT-list. Also there should
bea reference to the chapters under "Query Language (SQL) Functions" , especially sub-chapter "SQL Functions
ReturningSets"
The bigger picture here is that there's a lot of detail in 38.5 that
is of interest to users of built-in functions, not only to people
writing new functions. We've had discussions before about refactoring
that material so that some of it could be moved into a more prominent
place, probably in chapter 7 (Queries) or maybe chapter 9 (Functions
and Operators). Nobody's produced a coherent proposal though. In the
meantime I'm not much on board with sprinkling cross-references into
random places, if only because those references will be pointing to
the wrong place when/if this refactoring does happen.
regards, tom lane