Clone URL (Committers only): https://cms.apache.org/redirect?new=anonymous;action=diff;uri=http://jena.apache.org/documentation%2Ftdb%2Foptimizer.mdtext
[email protected] Index: trunk/content/documentation/tdb/optimizer.mdtext =================================================================== --- trunk/content/documentation/tdb/optimizer.mdtext (revision 1408513) +++ trunk/content/documentation/tdb/optimizer.mdtext (working copy) @@ -30,6 +30,7 @@ - [Abbreviated Rule Form](#abbreviated-rule-form) - [Defaults](#defaults) - [Generating a statistics file](#generating-a-statistics-file) + - [Generating statistics for Union Graphs](#generating-statistics-for-union-graphs) - [Writing Rules](#writing-rules) ## Quickstart @@ -290,6 +291,23 @@ *location*/stats.opt because when the command starts it will find an empty statistics file at that location. +### Generating statistics for Union Graphs + +By default `tdbstats` only processes the default graph of a dataset. However +in some circumstances it is desirable to have the statistics generated +over Named Graphs in the dataset. + +The `tdb:unionDefaultGraph` option will cause TDB to synthesize a default +graph for SPARQL queries, from the union of all Named Graphs in the +dataset. + +Ideally the statistics file should be generated against this +union graph. This can be achieved using the `--graph` option as follows: + + tdbstats --graph urn:x-arq:UnionGraph --loc /path/to/indexes + +The `graph` parameter uses a built-in TDB [special graph name](/documentation/tdb/datasets.html#special-graph-names) + ## Writing Rules Rule for an inverse functional property: @@ -320,4 +338,4 @@ ((VAR rdf:type class) ...) -is a useful selective rule. +is a useful selective rule. \ No newline at end of file
