Help with indexing in PHP

Question

Hello,
I use dbxml version 2.2.13 with PHP.
I am trying to index a document but seems that without success because the performance doesn't change.
The doc has 1600 elements and executing a query takes about 0.22 secs
The xquery looks like this (a bit simplified):
<pre>
declare namespace ns1 = "urn:...";
declare function local:foo ($p1 as element(), $p2 as element()) as item() {
let $a := data($p2/AAA)
let $b := data($p2/BBB)
let $r := $p1//CCC/*[name()=\$a][@ns1:attr1=\$b]
return $r/DDD
local:foo( doc("...")/*[1] , ... )
</pre>
I create the container like this:
$mgr->createContainer($qcname,DBXML_INDEX_NODES);
I have 4 questions:
Q1) Which index strategy should I take?
I have tested using "CCC" , "node-element-presence-none" but no speed up occurs.
The qplan shows sth like:
<OQPlan>P(node-element-presence-none,=,CCC)</OQPlan>
So seems the index is correctly set.
It is strategy ok? Which other indexes should I use?
Q2) should the indexes be inserted before or after inserting the document, or is this irrelevant?
Q3) If I create the container from php as shown before, and then I open it with dbxml it shows:
Type of default container: NodeContainer
Index Nodes: off
However if I create the container directly from dbxml it
Type of default container: NodeContainer
Index Nodes: on
Why is that?
Q4) I need to repeat several times $mgr->query(....) . Does this affect somehow the data base acces performance?
I'd be glad if someone could help me to make the indexes work..
Best,
/Enric

Answer 1

Q2) should the indexes be inserted before or after
inserting the document, or is this irrelevant?In the sense that this will not affect what the indexes contain, this is irrelevent. However, we normally recommend adding indexes before documents, or you would risk a lengthy re-index operation.
Q3) If I create the container from php as shown
before, and then I open it with dbxml it shows:
Type of default container: NodeContainer
Index Nodes: off
However if I create the container directly from dbxml
it
Type of default container: NodeContainer
Index Nodes: on
Why is that?This is a bug in the PHP API - it is also why your indexes made no difference for you. You will need to create your container outside PHP using DBXML_INDEX_NODES.
Q4) I need to repeat several times $mgr->query(....)
. Does this affect somehow the data base acces
performance?If the query is run several times, you would benefit from preparing it once, and executing it from the XmlQueryExpression object.
John