Re: COPY (query) TO file - Mailing list pgsql-hackers

From Tino Wildenhain
Subject Re: COPY (query) TO file
Date
Msg-id 4480457D.8090007@wildenhain.de
Whole thread Raw
In response to Re: COPY (query) TO file  ("Mark Woodward" <pgsql@mohawksoft.com>)
Responses Re: COPY (query) TO file  ("Mark Woodward" <pgsql@mohawksoft.com>)
List pgsql-hackers
Mark Woodward wrote:
>> Mark Woodward wrote:
>>> Tom had posted a question about file compression with copy. I thought
>>> about it, and I want to through this out and see if anyone things it is
>>> a
>>> good idea.
>>>
>>> Currently, the COPY command only copies a table, what if it could
>>> operate
>>> with a query, as:
>>>
>>> COPY (select * from mytable where foo='bar') as BAR TO stdout
>>>
>>> I have no idea if it is doable, but I can see uses for replication
>> I doubt it be really usefull (apart from maybe saving some work
>> coding a client app) but did you actually test it with
>>
>> create table as select ...; followed by a copy of that table
>> if it really is faster then just the usual select & fetch?
> 
> Why "create table?"

Just to simulate and time the proposal.
SELECT ... already works over the network and if COPY from a
select (which would basically work like yet another wire
protocol) isnt significantly faster, why bother?

> The idea is that you would have one or more redundent databases and use
> the COPY TO/FROM to keep them up to date.

Well, if you have databases you would have regular tables - and
can use copy as it is now :-)

Regards
Tino



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