Entity Search, Find, and Explore - Documentation

Text Search

Enter a text pattern to look for. Finder will show a listing of entities with the text occurring in any literal property value or label. You may then continue to refine your search by filtering by type, property value, etc.

Entity URI (ID) Lookup

You can lookup an Entity URI using the autocomplete feature which performs lookups as you type. The OpenLink Finder recognizes some well-known namespace prefixes. For example: "dbpedia:"

Results Order & Ranking

On some listings, results are sorted using a combination of text match score and entity-attribute-value link coefficients. Thus, a small indicator graphic (horizontal bars in leftmost column) is used to unveil metrics for both rankings per entity; the top bar indicates the text score while the bottom covers the entity ranking. Hovering on either will reveal the actual value.

Text Scores

These are proportional to the frequency of the search terms in the match and if many terms are present, the score weight is increased by a proximity factor.

Entity Rank

Entity matches are ranked based on how frequently they are referenced by other entities. Rankings are increased as a function of the score of the referencing entity.

Timeouts

The Virtuoso 6.x engine includes a new "Anytime Query" feature that enables the optional use of a configurable response time threshold (timeout) when executing queries over large datasets. This feature protects against deliberate or inadvertent denial-of-service style resource-hogging that can arise from badly written or complex queries. When enabled, this feature lets you to set hard limit for resource usage per query associated with unauthenticated users. Queries execute until the response time limit threshold is reached, and, if partial results are available, they are returned with additional result set diagnostics flagging the partial nature of the result set. All query handling is partitioned thereby protecting against cross-client resource contention.

This service currently enforces a 20 second hard time limit for queries. Each query is first run with a 2 second timeout - if only a partial result or no results are received, the user is prompted to retry with double the previous time limit until the hard limit is reached.

OpenSearch

You can add this service as a search engine plugin in OpenSearch capable browsers. You can do this in Firefox by using the pulldown next to the search text input in Facet search main page.

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OpenSearch.org

Available datasets

The VoiD graph contains information about Linked Open Data Cloud datasets hosted by this instance.

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