The XSL Speed Optimizer command is enabled when an XSLT or XML document is active. It starts the XSL Speed Optimizer, which analyzes the possibility of carrying out faster transformations using the XSLT stylesheet being analyzed. The Optimizer works by running the XSLT stylesheet to be optimized over an XML dataset (one or more XML documents), and analyzing the stylesheet's performance. An optimization strategy is derived from this analysis and can be saved with the XSLT stylesheet (as a processing instruction at the end of the stylesheet). The optimized stylesheet can be used subsequently to produce faster transformations.
On clicking the command, you will be prompted to select, depending on whether an XSLT or XML document is active, respectively, an XML document or XSLT stylesheet. On clicking OK, the analysis starts. If the XSLT or XML document already has, respectively, an XML assignment or XSLT assignment in the document, this step is skipped, and the analysis starts straightaway. For details of how to use the Optimizer, see the section XSL Speed Optimizer. The settings of the Optimizer can be made in the XSL Speed Optimizer tab of the Options dialog (Tools | Options).