I'm confused, how would grabbing chunks of a huge result set be more efficient than grabbing the records by PK?
Couldn't you just have a select that grabbed the requested item, and passed it back to the consumer? Larry On 10/3/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > My problem with RowHandler is that iBATIS controls the iteration. I just say > > sqlMap.queryWithRowHandler ("getAllItems", rowHandler); > > and all items get processed by the rowHandler. > > But in my case I need to make iBATIS return items one-by-one when it is asked > to do so because the framework controls the iteration. > This is a very simplified basic logic of the framework: > > while (itemProvider.hasNext()) { > Object item = itemProvider.next(); > process(item); > } > > > > -----Original Message----- > From: Christopher Lamey [mailto:[EMAIL PROTECTED] > Sent: Wed 10/3/2007 11:55 PM > To: user-java@ibatis.apache.org > Subject: Re: how to map huge resultsets? > > Hmm...I don't see how having an external framework prevents you from using a > RowHandler. Your item provider could implement the RowHandler interface and > the external code wouldn't know or care about it. Or your item provider > could wrap something that does implement RowHandler so the external code > doesn't know it exists. The main point is that you can pull mapped objects > on a row by row basis from the database. > > How is a RowHandler different that what you were describing in your first > mail? > > On 10/3/07 3:33 PM, "[EMAIL PROTECTED]" > <[EMAIL PROTECTED]> wrote: > > > > > Thanks for your reply. > > > > I can't use the rowhandler callback because the iteration is external to > > iBATIS. In my case a batch framework iteratively asks for an item and > > processes it - and I am trying to implement an iBATIS item provider (I > > realize > > now I should have explained this in the initial post). > > > > Robert > > > > > > -----Original Message----- > > From: Christopher Lamey [mailto:[EMAIL PROTECTED] > > Sent: Wed 10/3/2007 11:06 PM > > To: user-java@ibatis.apache.org > > Subject: Re: how to map huge resultsets? > > > > Hello, > > > > You should take a look at the RowHandler interface and the > > queryWithRowHandler calls in SqlMapClient (page 61 of the pdf). Basically, > > the RowHandler gets invoked for every row returned rather than mapping all > > the rows into objects in a collection. > > > > Cheers, > > Chris > > > > > > On 10/3/07 2:37 PM, "[EMAIL PROTECTED]" > > <[EMAIL PROTECTED]> wrote: > > > >> Hello, > >> > >> I am wondering whether it possible to implement the following scenario with > >> iBATIS: > >> > >> 1. run an iBATIS-managed select > >> 2. get a scrollable result set instead of a list of mapped objects > >> 3. manually scroll the result set and ask iBATIS for object > >> corresponding > >> to current row > >> > >> Hibernate provides this possibility > >> (http://www.hibernate.org/hib_docs/reference/en/html/batch.html) so I > >> thought > >> it would be feasible with iBATIS too, but I couldn't figure out a way. The > >> motivation is a batch scenario where the select returns a huge number of > >> rows > >> so all mapped objects can't be loaded into memory at once. > >> > >> The iBATIS way I am aware of is to use queryForList(String statementName, > >> int > >> skipResults, int maxResults), but this means querying the database > >> (TOTAL_NUMBER_OF_ROWS / maxResults) times. > >> > >> Can somebody give advice about pros & cons of the two approaches? > >> > >> Thanks > >> Robert > >> > >> > >> This message is for the designated recipient only and may contain > >> privileged, > >> proprietary, or otherwise private information. If you have received it in > >> error, please notify the sender immediately and delete the original. Any > >> other use of the email by you is prohibited. > > > > > > > > > > This message is for the designated recipient only and may contain > > privileged, > > proprietary, or otherwise private information. If you have received it in > > error, please notify the sender immediately and delete the original. Any > > other use of the email by you is prohibited. > > > > > This message is for the designated recipient only and may contain privileged, > proprietary, or otherwise private information. If you have received it in > error, please notify the sender immediately and delete the original. Any > other use of the email by you is prohibited. > >