Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-26 Thread Giles Lean
Abhijit Menon-Sen a...@toroid.org wrote: Unless you explicitly declare and fetch from an SQL-level cursor, your many GBs of data are going to be transmitted to libpq, which will eat lots of memory. (The wire protocol does have something like cursors, but libpq does not use them, it retrieves

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Alex Goncharov
,--- I/Alex (Mon, 24 May 2010 12:25:18 -0400) * | No equivalent of FETCH_COUNT is available at the libpq level, so I | assume that the interface I am using is smart enough not to send | gigabytes of data to FE. | | Where does the result set (GBs of data) reside after I call | PQexecPrepared?

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Yeb Havinga
Alex Goncharov wrote: ,--- I/Alex (Mon, 24 May 2010 12:25:18 -0400) * | No equivalent of FETCH_COUNT is available at the libpq level, so I | assume that the interface I am using is smart enough not to send | gigabytes of data to FE. | | Where does the result set (GBs of data) reside after I

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Abhijit Menon-Sen
At 2010-05-25 07:35:34 -0400, alex-goncha...@comcast.net wrote: | Where does the result set (GBs of data) reside after I call | PQexecPrepared? On BE, I hope? Unless you explicitly declare and fetch from an SQL-level cursor, your many GBs of data are going to be transmitted to libpq, which

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Alex Goncharov
,--- Abhijit Menon-Sen (Tue, 25 May 2010 17:26:18 +0530) * | Unless you explicitly declare and fetch from an SQL-level cursor, your | many GBs of data are going to be transmitted to libpq, which will eat | lots of memory. (The wire protocol does have something like cursors, | but libpq does

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Andrew Chernow
On 05/25/2010 07:35 AM, Alex Goncharov wrote: ,--- I/Alex (Mon, 24 May 2010 12:25:18 -0400) * | No equivalent of FETCH_COUNT is available at the libpq level, so I | assume that the interface I am using is smart enough not to send | gigabytes of data to FE. | | Where does the result set (GBs

Re: [HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-25 Thread Andrew Dunstan
Alex Goncharov wrote: ,--- I/Alex (Mon, 24 May 2010 12:25:18 -0400) * | No equivalent of FETCH_COUNT is available at the libpq level, so I | assume that the interface I am using is smart enough not to send | gigabytes of data to FE. | | Where does the result set (GBs of data) reside after

[HACKERS] libpq, PQexecPrepared, data size sent to FE vs. FETCH_COUNT

2010-05-24 Thread Alex Goncharov
I have some libpq-using application code, in which fetching the data follows this logic (after a statement has been prepared): PQexecPrepared(pg_result, pg_conn, pg_statement_name, input_param_cnt, param_values, param_lengths,