stardog-admin index qc Manual Page

NAME


stardog-admin index qc —Print query cardinality

SYNOPSIS


stardog-admin index qc [ --error <Error> ] [ --errors-only ] [ {-s | --skip} ] [ --smooth <Smoothing factor> ] [--] <database> <query>...

OPTIONS


--error <Error>
Percentage of error above which will be reported as error by adding an error marker to the corresponding plan node. Error percentage in cardinality is computed as (Estimated - Actual) / (min(Actual, Estimated) + accuracy). Set it to -1 to disable error markers.
--errors-only
Print the query plan only if there is an error
-s, --skip
Enable skipping for cardinality computation. Skipping is enabled for normal query execution but disabled when --cardinality is specified. Without skipping query execution might take significantly more amount of time but cardinality values will be accurate. With skipping we cannot compute the exact cardinality since we don't know how many elements are skipped which might cause bogus error markers in the output.
--smooth <Smoothing factor>
Value that will be added to actual cardinalities to smooth out error percentages for small cardinalities. Without this value the error for estimating cardinality of 2 for an actual cardinality of 4 would be 100% which is misleading sincethat is pretty accurate.
--
This option can be used to separate command-line options from the list of argument, (useful when arguments might be mistaken for command-line options
<database> <query>
Stardog database to query; this is the path to an existing database directory. The subsequent arguments are one or more SPARQL query strings to execute. This can either be a file name or a SPARQL query string.

DISCUSSION


Runs a query against an index directly and prints the cardinality of each plan node.

EXAMPLES


Runs a query

    $ stardog-admin index query -q 'select ...' /path/to/stardog/database