Re: Proposal: new function array_init

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Proposal: new function array_init
Date: 2008-06-02 16:46:44
Message-ID: 20173.1212425204@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

"Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com> writes:
> There was more time questions about array's initialisation. I propose
> function array_init.

> CREATE OR REPLACE FUNCTION array_init(sizes int[], v anyelement)
> RETURNS anyarray;

I think this is basically a good idea, but maybe the API needs a bit of
adjustment --- providing the sizes as an array doesn't seem especially
convenient. Since we only allow up to 6 dimensions (IIRC), what about
six functions with different numbers of parameters:

array_int(int, anyelement)
array_int(int, int, anyelement)
...
array_int(int, int, int, int, int, int, anyelement)

I don't object to having the array-input version too, but seems like in
most cases this way would be easier to use. It wouldn't work well
for providing lower bounds too, but maybe the array-input case is
sufficient for that.

Other thoughts:

* Should the fill value be the first parameter instead of the last?
I'm not sure either way.

* I have a mild preference for "array_fill" instead of "array_init".

* We can handle a null fill value now, but what about nulls in the
dimensions? The alternatives seem to be to return a null array
(not an array of nulls) or throw error.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Greg Smith 2008-06-02 16:47:42 Re: Overhauling GUCS
Previous Message David E. Wheeler 2008-06-02 16:45:27 Re: Case-Insensitve Text Comparison