The eXist XML database is used as back-end for the Metadata Catalogue (MDC). For good performance of this database it is mandatory to enable proper indices.

Configure index

To configure an index the following steps have to be performed:

• Generate collection.xconf file
• Start eXist client interface
• Use command mkcol to create collections /db/system/config/db/mdc/ensemble and /db/system/config/db/mdc/config.
• Add collection.xconf file to the collection.
• Change to /db/mdc/ensemble or /db/mdc/config and rebuild index (see below).

The content of the file collection.xconf depends on the collection. For the collection of ensemble XML files use:

<collection xmlns="http://exist-db.org/collection-config/1.0">
  <index xmlns:ensemble="http://www.lqcd.org/ildg/QCDml/ensemble1.4">
    <create qname="ensemble:markovChainURI" type="xs:string"/>
    <ngram qname="ensemble:markovChainURI"/>
  </index>
</collection>

For the collection of configuration XML files use:

<collection xmlns="http://exist-db.org/collection-config/1.0">
  <index xmlns:config="http://www.lqcd.org/ildg/QCDml/config1.3">
    <create qname="config:markovChainURI" type="xs:string"/>
    <create qname="config:dataLFN" type="xs:string"/>
    <ngram qname="config:markovChainURI"/>
    <ngram qname="config:dataLFN"/>
  </index>
</collection>

Rebuild of index

Rebuild of the indices can be triggered using the following commands:

client.sh -u admin -s -ouri=xmldb:exist://localhost:8088/xmlrpc -c /db/mdc/ensemble -i
client.sh -u admin -s -ouri=xmldb:exist://localhost:8088/xmlrpc -c /db/mdc/config -i