Retrieve query execution plan.
A TaminoQPIExplain is a query pragma that has the form of a
QPI (query processing instruction), i.e., it is enclosed by
"{?" and "?}". If you use
this pragma, the query will not be executed. Instead, an XML representation of
the execution plan for the query expression is returned in the result document.
You can use this information to determine which access paths will be used for
Tamino data during query execution.
The following operator elements are of interest:
XqcUnnestCollectionScan |
retrieve all documents of the current collection |
XqcUnnestDoctypeScan |
retrieve all documents of a doctype |
XqcUnnestStdIdxScan |
index-based retrieval of documents |
The doctype scan operator contains information on which doctype it refers to. The index scan operator additionally contains information on the actual index, the index comparison operator and the comparison value.
{?explain?} input()/entry[@name="Hoch Franz"]
The result document contains this
XqcUnnestStdIdxScan operator:
The following construct(s) refer to this construct: