MarkLogic 12 Product Documentationprof:value
prof:value( $expr as xs:string, [$map as map:map?], [$context as item()?], [$options as (element()|map:map)?] ) as item()*
Summary
Evaluate an expression in the context of the current evaluating
statement and return the profiling report for its evaluation.
This differs from prof:eval in that prof:value
preserves all of the context from the calling query, so you do not
need to re-define namespaces, variables, and so on. Although the expression
retains the context from the calling query, it is evaluated in its own
transaction.
For details on profiling requests and interpreting the output of a profile request, see Profiling Requests to Evaluate Performance.
| Parameters | |
|---|---|
| expr | The string representing an expression to evaluate. |
| map | A map of namespace bindings. The keys should be namespace prefixes and the values should be namespace URIs. These namespace bindings will be added to the in-scope namespace bindings in the evaluation of the path. |
| context | Bind the context item to this value during evaluation of the expression. |
| options |
Options with which to customize this operation.
You can specify options as either an options XML element
in the namespace "xdmp:eval", or as a map:map. The
option names below are XML localnames. When using a map, replace any
hyphens in an option name with camel casing. For example, "an-option"
becomes "anOption" when used as a map:map entry key.
This function supports the following options:
true, the code is evaluated without using Amps from the caller.
For more details, see
Temporarily Increasing Privileges with Amps.
This option is not usable with dbg:eval.
true, the expression runs as if outside of an
HTTP App Server: builtins that read the request (e.g.
xdmp:get-request-header) or write the response (e.g.
xdmp:add-response-header) behave as if called outside of
an HTTP context, typically returning the empty sequence.
Session-related builtins likewise have no session to read or update;
in particular, xdmp:set-session-field returns the set value instead of creating a new session.
This option is intended as a defense-in-depth control when profiling
user-supplied expressions, and is typically used together with
ignore-amps.
|
Required Privileges
http://marklogic.com/xdmp/privileges/xdmp-value and either
http://marklogic.com/xdmp/privileges/profile-my-requests or
http://marklogic.com/xdmp/privileges/profile-any-requests
Usage Notes
You can only evaluate and profile expressions with
prof:value; no
prolog definitions (namespace declarations, function definitions,
module imports, and so on) are allowed.
Example
prof:value("xdmp:random()")
=> (<prof:report>...</prof:report>,9478952250821284456)