Re: number of rown in a cursor.
От | Christoffer Gurell |
---|---|
Тема | Re: number of rown in a cursor. |
Дата | |
Msg-id | 20050124183816.GA29580@h55p111.delphi.afb.lu.se обсуждение исходный текст |
Ответ на | Re: number of rown in a cursor. (Scott Marlowe <smarlowe@g2switchworks.com>) |
Ответы |
Re: number of rown in a cursor.
|
Список | pgsql-general |
> yep. This is because one of the advantages of a cursor is that it only > runs partially and returns the first X rows for the fetch. This keeps > load down so that many cursors hitting the machine at once don't all > materialize all their rows and chew up all that I/O, cpu, and memory. > Unfortunately, one of the side effects of this methodology is that no > one knows how many rows there really are until they've been fetched. the thing is that i want to create a gui-widget that has the possibility to show a large amount of data over a slow connection. My idea was that i create a cursor and create a srollbar with the number of rows in the cursor so the user can scroll and only fetch the rows displayed from the cursor as the user releases the scrollbar. If i understand right then the way to do this is: create the cursor, move to the end to get the number of rows, move to the front. get data. am i right? or is there a better way to achieve this ? perhaps with a local view?
В списке pgsql-general по дате отправления: