Re: Convert Arbitrary Table to Array?

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От Lee Hughes
Тема Re: Convert Arbitrary Table to Array?
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Msg-id 2d739b560902091014i1f11f04dhfee7a29fea13d720@mail.gmail.com
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Ответ на Re: Convert Arbitrary Table to Array?  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: Convert Arbitrary Table to Array?  (Tom Lane <tgl@sss.pgh.pa.us>)
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Good point on scalability -- I am planning to limit the number of rows fetched through LIMIT or a Cursor once I have the basics working.

Did you mean select array(select * from mytable);  ?

Thanks for your help, I will try this approach.

Lee

On Mon, Feb 9, 2009 at 9:20 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Lee Hughes <lee@hughesys.com> writes:
> Hi, I need a function that accepts a table name and returns a 2-dimensional
> array of the table data.

Well, in 8.3 and up there are arrays of composite types, so you can
do something like

               select array(select mytable from mytable);

However you are not going to be able to encapsulate that as a function
real well, because of the question of what is the function's result
type.

You should also realize that this approach is not going to scale to
large tables.  You don't want to get into pushing around arrays of more
than say a couple of megabytes.

Personally I'd be wondering exactly where this requirement comes from
and whether it doesn't betoken severe database-ignorance in the
application design.

                       regards, tom lane



--
Lee
503-753-7620

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