Re: Odd array issue - Mailing list pgsql-general

From Craig Ringer
Subject Re: Odd array issue
Date
Msg-id 49774725.1060105@postnewspapers.com.au
Whole thread Raw
In response to Re: Odd array issue  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Tom Lane wrote:
> Craig Ringer <craig@postnewspapers.com.au> writes:
>> The following query should return 2 records, but returns zero instead:
>
>> test=> select x, regexp_matches(x::text, 'm')
>> test-> FROM generate_series(1,2) AS x;
>>  x | regexp_matches
>> ---+----------------
>> (0 rows)
>
> No, that's correct.  The SRF returns an empty set, so there are no
> output records.  The behavior you seem to be imagining would make it
> impossible to distinguish empty set from a single row containing NULL.

Aah, that makes sense. For some reason I'd been thinking of
regexp_matches as returning a single array, rather than returning a set
of scalar values. RTFM (better) I guess. Sorry.

Thanks for taking a look, it's appreciated.

--
Craig Ringer

pgsql-general by date:

Previous
From: Merlin Moncure
Date:
Subject: Re: bytea size limit?
Next
From: Grzegorz Jaśkiewicz
Date:
Subject: Re: autovacuum daemon