Re: [GENERAL] query large amount of data in c++ using libpq

[Henrik]

19 aug 2007 kl. 06:34 skrev Felix Ji:


Hi all,
i am using PQexecParams() to SELECT about 3 million record in C+ 
+, and it takes several minutes to make it done with used memory  
dramatically incresed(about 200MB).
it seems when i using PQexecParams(), i can't use the query result  
before all the data is sent to client.

is there something like server side cursor in libpq?
or is there any other way to do this in c++?
some articles say that query for large amount of data is  
automaticall handled well by pg, but i can't see how.


thanks

libpqxx is what you need. then you can use cursors in c++.

cheers,
henke

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[GENERAL] query large amount of data in c++ using libpq

[Felix]

Hi all,
i am using PQexecParams() to SELECT about 3 million record in C++, and it
takes several minutes to make it done with used memory dramatically
incresed(about 200MB).
it seems when i using PQexecParams(), i can't use the query result before
all the data is sent to client.
is there something like server side cursor in libpq?
or is there any other way to do this in c++?
some articles say that query for large amount of data is automaticall
handled well by pg, but i can't see how.

thanks

[GENERAL] query large amount of data in c++ using libpq

[Felix Ji]

 Hi all,
i am using PQexecParams() to SELECT about 3 million record in C++, and it
takes several minutes to make it done with used memory dramatically
incresed(about 200MB).
it seems when i using PQexecParams(), i can't use the query result before
all the data is sent to client.
is there something like server side cursor in libpq?
or is there any other way to do this in c++?
some articles say that query for large amount of data is automaticall
handled well by pg, but i can't see how.

thanks