Re: are cursors necessary?
От | Jan Wieck |
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Тема | Re: are cursors necessary? |
Дата | |
Msg-id | 3FCFC733.9000906@Yahoo.com обсуждение исходный текст |
Ответ на | Re: are cursors necessary? (Richard Huxton <dev@archonet.com>) |
Ответы |
Re: are cursors necessary?
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Список | pgsql-general |
Richard Huxton wrote: > On Thursday 04 December 2003 22:46, Mark Harrison wrote: >> res = PQexec(conn, "BEGIN"); >> res = PQexec(conn, "DECLARE myportal CURSOR FOR select * from >> pg_database"); res = PQexec(conn, "FETCH ALL in myportal"); >> res = PQexec(conn, "CLOSE myportal"); >> res = PQexec(conn, "END"); > >> Is there any value in my own query-only programs to declaring the cursor >> for each search? > > Well - if you want to scroll forward/backward through the resultset, you'd > want a cursor. Or, if your client had limited memory and the resultset was > large you might want to do so. PG will return all rows at once, so if your > SELECT returns 5 million rows you'll use a lot of RAM on the client side. > You really think people would ever want to store more than 640 rows? Jan -- #======================================================================# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #================================================== JanWieck@Yahoo.com #
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