Re: information_schema.columns changes needed for OLEDB

Tom,
this is very helpful - thank you so much!

I had to discover those 'missing' functions one by one, usually after users'
complaints.

Konstantin

On Fri, May 29, 2009 at 11:35 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Konstantin Izmailov <pgfizm(at)gmail(dot)com> writes:
> > you know that some Postgres functions are listed in pg_proc while others
> are
> > not. For example, all Data Type Formatting function are in pg_proc
> (to_char,
> > to_hex, ...). While several of the Date/Time Functions are not there
> > (extract, localtime, ...).
>
> The ones that appear not to be there are ones that the SQL standard
> demands special weird syntax for. The grammar translates such calls
> to standard function calls to underlying functions, which usually are
> named a bit differently to avoid confusion. For instance
> extract(field from some_expr) becomes date_part('field', some_expr).
>
> If you want to know what all of these are, see the func_expr production
> in parser/gram.y.
>
> > This causes issues to Windows integration as well.
>
> Complain to the SQL standards committee, especially to those members
> who seem to think COBOL represented the apex of programming language
> syntax design :-(
>
> regards, tom lane
>