Low performance of listing graph

Virtuoso Universal Server
1

Hello,
After loaded 100 millions triples into Virtuoso, it’s not able to show graph list by WEB UI(Conductor) because it’s loading all the time, including querying the SPARQL below:

SELECT DISTINCT ?g
WHERE
{GRAPH ?g {?s ?p ?o}}

Thanks!

2

Graph listing is an expensive operation and as a result the more graph in the Quad Store the longer it will take to list them. How many graphs are in the database?

SELECT COUNT ( DISTINCT ?g ) WHERE { GRAPH ?g { ?s a ?t } } ;

Note also this tip on How to obtain all graphs with provides an alternative query { ?s a ?t } which should be more performant and a function for listing graphs.