AllegroGraph Query Plan

Question

Is it possible to view the query execution plan for evaluating a SPARQL query in AllegroGraph (something like EXPLAIN).

Answer 1

There is no explain query command in SPARQL, but here are two ways to execute SPARQL queries with verbose output which includes the query plan:

• click "Show Plan" in AllegroGraph Webview;
• or add the AllegroGraph query option PREFIX franzOption_logQuery: <franz:yes> to the query, which will write an execution log to agraph.log

Answer 2

AllegroGraph provides a query analyzer through a Lisp API and REST API that will tell you what indices are being utilized. For more information, look at the following link (this is for AllegroGraph v4.14.1):

http://franz.com/agraph/support/documentation/v4/query-analysis.html