Chapter 48. Virtual Index Definitions

Table of Contents

Keyword Virtual Index Definition
Configuring Virtual Index Definitions
Search Term Highlighting in Search Results

Virtual index definitions can be configured in Evergreen to create customized search indexes that make use of data collected by other (real) index definitions. Real index definitions use an XPath expression to indicate the bibliographic data that should be included in the index. Virtual index definitions bring together data collected by other index definitions to create a new, virtual index. They can also use an XPath expression to collect data directly for an index, but they are not required to.

All index definitions can be modified by having other indexes map to them. For example, Genre could be added to the All Subjects field definition in the Subject index. This would allow users to search Genre as part of a Subject search.

Keyword Virtual Index Definition

Evergreen now uses a virtual index definition for the Keyword index. This allows libraries to customize the keyword search index by specifying which fields are included in the keyword index, as well as how each field should be weighted for relevance ranking in search results. By default, the keyword index contains all of the search fields other than the keyword definition itself. Each field is assigned a weight of 1, with the exception of Title Proper, which is assigned a weight of 8. A match on the Title Proper within a keyword search will be given the higher weight and therefore a higher relevance ranking within search results.

  1. To view the stock virtual index definition for keyword searches, go to Administration>Server Administration>MARC Search/Facet Fields and select the Keyword Search Class.
  2. Locate the field labeled "All searchable fields". This is the general keyword index.
  3. The weight of a field can be modified by selecting the field and going to Actions>Edit Record or right-clicking and selecting Edit Record.

    1. The Metabib Field Virtual Map modal will appear. Increase the weight of the field and click Save.