Re: What language is faster, C or PL/PgSQL?

On Mon, Feb  4, 2013 at 08:33:02AM -0600, Merlin Moncure wrote:
> On Sat, Feb 2, 2013 at 11:36 AM, Carlo Stonebanks
> <stonec.register@sympatico.ca> wrote:
> > Here is an advantage Plpgsql has:
> > http://www.postgresql.org/docs/9.1/static/plpgsql-expressions.html
> >
> > I guess you can offset this by creating your own prepared statements in C.
> > Otherwise, I can’t think of how C could be slower. I would choose C for
> > functions that don’t have SQL statements in them – e.g. math and string
> > processing.
>
> For cases involving data processing (SPI calls), C can be slower
> because pl/pgsql has a lot of optimizations in it that can be very
> easy to miss.  I don't suggest writing backend C functions at all
> unless you are trying to interface with a C library to access
> functionality currently not exposed in SQL.

How is PL/pgSQL faster than C?  I thought we had optimized PL/pgSQL to
save parsed functions, but I don't see how that would help with queries,
which use SPI.  Am I missing something?

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +