the Idea is good.
Consideration though should be at a layer where all DB used by ofbiz can
implements something similar. mysql and Postgresql are two main ones
used. ms sql is also used.
this is the reason, for instance that all indexes are limited to 30
since one of the db, that is its maximum index length.
you will find in the Data layer that ofbiz creates temporary procedure
or Functions calls to those DB that support that.
=========================
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
Marc Morin sent the following on 12/3/2010 6:26 AM:
We make extensive use of view entities in our ofbiz application. We have
noticed that when there is a large dataset and under some complex views, the
query performance was not the best (not a index issue, just complex joins,
etc...).
With some commercial databases like Oracle, etc... we would have used
materialized view semantics available for these dbms, but we are using
PostgreSQL.
So, we have extended the entity layer in Ofbiz to perform the materialization.
This is pretty slick as all you need to do is the following:
<view-entity name="myView" materialize="true">...</view-entity>
and the system will do the following:
- create a backing entity called "myView" that has the same fields as the view
- backing entity has all the indexes inherited from the component entities
- relations (fk,...) inherited from the component entities.
- perform all the ECA actions automatically on all entities used in the view
(direct members and nested members if case of view on views). (This is an eager
update strategy only).
So, the application doesn't change, it still accesses "myView", but now, it's
result is returned from the backing entity instead of the complex SQL statement.
We're pretty excited about this feature!!! Really pushes Ofbiz framework to
next level and allows materialized views to be more broadly used on dbms that
don't naturally support it.
We are prepared to contribute this feature back to the community if desired. A
note of caution about it though.... we have added a visitor pattern to the
model entities and this feature makes use of it. It would need to come with it.
Please advise.
Marc Morin
Emforium Group Inc.
ALL-IN Software
519-772-6824 ext 201
mmo...@emforium.com
