Re: function side effects

On tis, 2010-02-23 at 16:54 -0500, Jaime Casanova wrote:
> On Tue, Feb 23, 2010 at 2:02 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >
> > There may be some value in inventing a "has no side effects" marker, but
> > that should not be confused with IMMUTABLE/STABLE.
> >
> 
> a READONLY function?

SQL standard:

<SQL-data access indication> ::=
NO SQL
| CONTAINS SQL
| READS SQL DATA
| MODIFIES SQL DATA

Notice also that this is separate from

<deterministic characteristic> ::=
DETERMINISTIC
| NOT DETERMINISTIC

which is the SQL standard's variant of volatility.

So someone has already had the idea that these two should exist
separately.