Metadata statistics

The metadata statistics page's path is Home > Administer > eXtensible Catalog (XC) > Metadata Storage Configuration and Utilities > Statistical data (admin/xc/metadata/statistics). It is available only for administrators. Its sole purpose is to give you information about the number of records inside the Drupal Toolkit.

It contains three states: before harvest (the state of DT before last harvest), after harvest (the records covered in the last harvest) and current (the actual state). Each state has the following properties:

• All entities - the number of rows in xc_entity_properties table
• Work - the number of FRBR work level records
• Expression - the number of FRBR expression level records
• Manifestation - the number of FRBR manifestation level records
• Holdings - the number of FRBR holdings level records
• Dublin Core - the number of Dublin Core records
• Metadata - the number of rows in xc_sql_metadata table
• Nodes - the number of rows (all kinds)
• Relations - the number of relations between FRBR entities (the number of rows in xc_entity_relationships table)
• New - the number of new records (only for the harvest state)
• Updated - the number of updated records (only for the harvest state)
• Deleted - the number of deleted records (only for the harvest state)

The nodes should be at least as much as the number of manifestations. If somebody looking a schema view new nodes created for work, expression and holdings level records, so the actual number might be larger than the number of manifestations. These numbers are counted by SQL queries embeded in the Drupal module.

The SQL queries are the following:
1) counting the number of entities, metadata, nodes and relationships:

SELECT
  (SELECT count(*) FROM xc_entity_properties) AS entities,
  (SELECT count(*) FROM xc_sql_metadata) AS metadata,
  (SELECT count(*) FROM node) AS nodes,
  (SELECT count(*) FROM xc_entity_relationships) AS relations

2) counting the instances of each entity types:

SELECT metadata_type, COUNT(metadata_type) AS count 
  FROM xc_entity_properties 
  GROUP BY metadata_type

During harvest DT counts the number of incoming records, and the second state (the number of harvested records) is based on these counters.

The numbers should be consistent with Solr index. The state of the index can be checked in another page: Home > Administer > eXtensible Catalog (XC) > Solr Setup and Indexing > Information about Solr index (admin/xc/solr/info). It contains not only the number of documents, but it lists all the fields, and the top terms inside a given fields. The general principle is, that the number of Solr documents should be the same as the number of manifestations.

This page is generated by making use of Solr's Luke handler requests. The response is cached, because it takes for a while it is generated, but there is a flag which guarantees that you always see the actual data.