Hi all,
I've noticed (and read) that XPath queries which supply a path constraint
are slow due to the extra lookup required to account for the hierachical
structure.
I have Order nodes which represent customer orders.
I have OrderElement nodes which represent each item (product) and quantity
that makes up the Order.
Here is an excerpt from my custom node definition file:
[jpg:order] > nt:hierarchyNode, mix:referenceable
- jpg:transactionUUID (STRING)
- jpg:customerAccountUUID (STRING) mandatory
- jpg:orderStatus (LONG) mandatory
- jpg:cost (DOUBLE) mandatory
+ orderElements (jpg:default)
= jpg:orderElement primary copy
[jpg:orderElement] > jpg:default
- jpg:productUUID (STRING) mandatory
- jpg:quantity (LONG) mandatory
- jpg:cost (DOUBLE) mandatory
- jpg:orderUUID (STRING) mandatory
- jpg:isRefunded (BOOLEAN) = 'false'
- jpg:refundedDate (DATE)
The image below shows the structure:
http://jackrabbit.510166.n4.nabble.com/file/n2532925/shop_orders_structure.png
I need to get the Orders for a particular customer where the Order contains
an OrderElement for a particular product. Here is my XPath query:
//element(*,
jpg:order)[...@jpg:customerAccountUUID='aaa1bbab-ee77-48a5-8e83-214689f73deb']/orderElements/element(*,
jpg:orderElement)[...@jpg:productUUID = '23b5b2d6-1b63-42c9-8398-8cac8c296267']
For customers with many orders, the query is really slow (a few seconds). I
have 5000 Order nodes each of which have 1 - 6 OrderElement nodes. So I
could have approximately 20,000 customer order related nodes.
Is there any way at all to improve the use of a query that supplies a path?
I cannot see another way to do this unless I include the customerAccountUUID
property in OrderElement nodes, then I could use the query:
//element(*,
jpg:orderElement)[...@jpg:customerAccountUUID='aaa1bbab-ee77-48a5-8e83-214689f73deb'
and @jpg:productUUID = '23b5b2d6-1b63-42c9-8398-8cac8c296267']
... which I assume would be faster as I am not supplying path constraints.
It seems strange to me that queries with path constraints are slow but one
of the main points of JCR is to offer hierachical structure.
I read about Index Aggregates - would these help? It sounds like they might
- the description: "Sometimes it is useful to include the contents of
descendant nodes into a single node to easier search on content that is
scattered across multiple nodes."
Sometimes it is useful to include the contents of descendant nodes into a
single node to easier search on content that is scattered across multiple
nodes.
--
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http://jackrabbit.510166.n4.nabble.com/XPath-Query-Performance-with-Path-Constraints-Index-Aggregate-tp2532925p2532925.html
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