Determine parameters of query execution.
A TaminoQPIExecution is a query pragma that has the form of
a QPI (query processing instruction), i.e., it is enclosed by
"{?" and "?}". You can
use it to take influence on the query execution itself. This is useful to avoid
running out of memory during the execution of user-defined functions,
especially if they use recursion. The following parameters are supported:
call-stack-depth |
restrict the depth of the stack for user-defined functions (default value is 256) |
document-cache-size |
maximum cache size during query execution in MB; this way you can use it flexibly for single queries instead of the global server parameter XQuery_document_cache_size |
memory |
amount of memory available to a single query
processing thread during query execution in MB; it cannot be less than the
maximum cache size determined by the value of either the execution parameter
document-cache-size or of the server parameter
XQuery_document_cache_size.
|
The following execution pragma sets the available memory per query thread to 100MB and the maximum call stack depth to 1000. The document cache size is not set here and therefore determined by the value of the server parameter XQuery_document_cache_size:
{?execution memory="100" call-stack-depth="1000"?}
The following construct(s) refer to this construct: