We just issue a count(*) query first to get the count. Then, we use individual queries to get each page's data. If you feel confident enough that the count won't change (or you don't really care if it does), you can cache the value returned from it the count query (I don't know how often that gets called, really). If calling the queries to get the individual page's data is killing your database, then you're doing something wrong, IMHO.
On Wed, Nov 26, 2008 at 10:32 AM, Wayne Pope < [EMAIL PROTECTED]> wrote: > Hi, > > thanks for the replies. > > Micheal O/Hoover - I still don't see how this works as you don't have the > limit and offset (that is used in Iterator). How do you know how many rows > to load in your size() method? > > Michael S - thanks for the link - it it appears I must completely rewrite > the whole pagable/provider code (not looked at the code) to get this to > work? > > I'm sure I must be missing something still, as I can't beleive that we need > to either a) load the whole data set b) call count on the Db , then load in > the iterator mehod. Thats going to kill the database in prod (or really not > help.) > > On Wed, Nov 26, 2008 at 3:58 PM, Michael Sparer <[EMAIL PROTECTED] > >wrote: > > > > > have a look at https://issues.apache.org/jira/browse/WICKET-1784 > > > > > > Wayne Pope-2 wrote: > > > > > > Ok, > > > > > > I was just having a bit of code clean up and I realized that in our > > > IDataProviders we are loading all rows for a given dataset. > > > So looking at the iterator method I see we can limit the result (and > the > > > offset). Great I thought - however I see that that the size() method is > > > called as part of the getViewSize() in the AbstractPageableView. Thus I > > > need > > > to call the database here to figure out the size. > > > > > > Am I doing sonething wrong or have I got to hit the database twice for > > > each > > > DataProvider render. > > > > > > Obvously I don't want to hard code a size. Is there any other way ? > > > > > > Thanks > > > Wayne > > > > > > > > > > > > ----- > > Michael Sparer > > http://talk-on-tech.blogspot.com > > -- > > View this message in context: > > > http://www.nabble.com/Is-there-any-other-way--DataProviders-must-hit-the-Db-twice-for-%28possible%29-large-datasets-tp20701684p20702476.html > > Sent from the Wicket - User mailing list archive at Nabble.com. > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > >
