Re: Copy command Faster than original select - Mailing list pgsql-performance

From Pavel Stehule
Subject Re: Copy command Faster than original select
Date
Msg-id CAFj8pRDkenXG8-cAMuGNgyjoR9Ne+RRA5xdz1DWiuLqWDdKX7g@mail.gmail.com
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In response to Copy command Faster than original select  (belal <belalhamed@gmail.com>)
Responses Re: Copy command Faster than original select
List pgsql-performance
Hi

2015-02-06 9:30 GMT+01:00 belal <belalhamed@gmail.com>:
I made complex select using PGAdmin III Query Editor, Postgre server 9.3


select ... from mytable join .. join ... order by ....

I get [Total query runtime: 8841 ms. 43602 rows retrieved.]

but when I use

copy ([same above select]) to '/x.txt'
I get [Query returned successfully: 43602 rows affected, 683 ms execution
time.]

these test made on the same machine as the postgresql server.


can anyone explain huge difference in executing time?

probably terrible uneffective execution plan

can you send a explain analyze of your slow query?

Regards

Pavel

 

best regards all



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