Create environment for query processing.
The following construct(s) refer to this construct:
The Prolog prepares the environment in which the query
processing takes place. The environment is defined for the module that contains
the prolog, since the main module as well as any library module may contain
their own prolog. A prolog is roughly organized into two parts. The first part
contains module imports and several declarations that affect either query
processing (DefaultCollationDeclaration) or the interpretation of
QNames within the query (NamespaceDeclaration and
DefaultNamespaceDeclaration). The second part consists of
declarations of variables and functions. They appear at the end of the prolog
because the imports and declarations in the first part may have impact on
them.
Declarations and imports may all be followed by one or more pragmas each of which is followed by a semicolon and optional pragmas. These are directives for the query processor and control the way Tamino processes the query and outputs the query result.
Declarations, module imports and pragmas can only occur in the query prolog. It is an error to place them in the query body.
