TaminoQPIExecution

Determine parameters of query execution.

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Related Syntax Constructs

The following construct(s) refer to this construct:


Syntax

TaminoQPIExecution

graphics/TaminoQPIExecution.png

NCName StringLiteral

Description

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.

Example

  • 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"?}