Is there a find mothed that can one by one page return result in GenericDelegator?

[yong lin-2]

Dear All:
    Is there a find mothed that can one by one page return result in GenericDelegator? On the application system when very large data get all data is long time. So one by one page return result is very quick!  




2010-11-13



showsscel.ofbiz

[BJ Freeman]

speed of find is based on size of database and the indexing.
some databases are limited to the size of the indexing.
ofbiz is set to the size of the smallest DB (mysql)
so if you want better indexing choose a db that has more ability and
make changes to ofbiz.




=========================
BJ Freeman
Strategic Power Office with Supplier Automation  <http://www.businessesnetwork.com/automation/viewforum.php?f=52>
Specialtymarket.com  <http://www.specialtymarket.com/>
Systems Integrator-- Glad to Assist

Chat  Y! messenger: bjfr33man
showsscel.ofbiz sent the following on 11/13/2010 8:03 AM:

> Dear All:
>      Is there a find mothed that can one by one page return result in GenericDelegator? On the application system when very large data get all data is long time. So one by one page return result is very quick!
>
>
>
>
> 2010-11-13
>
>
>
> showsscel.ofbiz
>

[James McGill-5]

On Sat, Nov 13, 2010 at 9:03 AM, showsscel.ofbiz
<[hidden email]>wrote:

> Dear All:
>    Is there a find [method] that can one by one page return result in
> GenericDelegator? On the application system when very large data get all
> data is long time. So one by one page return result is very quick!
>
>

Partial selects are a universal problem with RDMS.  In systems that allow
persistent connections and long-running transactions you can use open
cursors, but we don't have that luxury, especially not in a framework that
must be independent of the database implementation.

In order to make meaningful partial selects, the query must first of all
define a total order so that you can get a result set for "a page" or
whatever unit that you need.  Since we can not make an assumption like that
for a general case, it's not really reasonable to make this optimization in
the delegator.

With that in mind, consider the approach that paginating screens are
using.   Look at how performFind queries work, with the EntityListIterator,
such as in the Facility app for InventoryItems.  This design is efficient
enough for millions of inventory rows when running on modest hardware.

--
James McGill
Phoenix AZ