Re: Default order of select datname from pg_database

Ah... I see, that clarifies things. Thank you all for your responses!

All started because I looked a script that is used in our company to backup
databases and it seemed odd that the query didn't use an order by sentence
which would be helpful, that way I could anticipate when a particular
database is going to be backed up, it's easy to fix though so no issues
there.

Again thank you all

Best regards
On Apr 19, 2014 10:47 AM, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> =?UTF-8?B?RWzDrWFzIERhdmlk?= <elias(dot)moreno(dot)tec(at)gmail(dot)com> writes:
> > By any change, does the following query have an "order by" by default
> when
> > omitted?:
>
> > select datname from pg_database;
>
> No. No SQL query ever has a "default" order by.
>
> > I executed that query against one of my servers and while looking at the
> > names it seems complety random, the order is always the same, for
> instance:
>
> An unqualified query is typically going to result in a sequential scan
> of the table, so what you're seeing is the current physical order of the
> tuples. This might change after adding/deleting/changing the properties
> of a database.
>
> regards, tom lane
>