Re: TODO item - Mailing list pgsql-hackers

From Andrew Gierth
Subject Re: TODO item
Date
Msg-id 873acxemql.fsf@news-spur.riddles.org.uk
Whole thread Raw
In response to Re: TODO item  (Bruce Momjian <bruce@momjian.us>)
Responses Re: TODO item  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
>>>>> "Bruce" == Bruce Momjian <bruce@momjian.us> writes:
>> The unnest() implementation is largely unrelated to the standard>> one, which is impossible to provide without
LATERAL.
Bruce> I removed the duplicate item; we can add more details aboutBruce> what additional functionality we need once we
getuserBruce> feedback.
 

The missing functionality from the spec is:

1) select ... from foo, unnest(foo.bar);   -- UNNEST is implicitly LATERAL

2) multiple arrays:  select * from unnest(a,b);

3) expansion of composite arrays: unnest(a) should return as many
columns as there are in the elements of a, not just one composite
column

4) WITH ORDINALITY - adds a column to the result with the array index

It's point (1) that's the killer - without it, unnest() is just a
trivial shorthand for stuff that can be done anyway; it doesn't
actually add any functionality.

-- 
Andrew.


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