Template Caching (SQLXML 4.0)
Applies to: 
SQL Server
Azure SQL Database
Template caching significantly improves performance. If template caching is set, the template remains in memory upon its first execution. This improves the performance for the subsequent execution of the template.
You can set the template cache size by adding the following key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSSQLServer\Client\SQLXML4\TemplateCacheSize
Caution
Incorrectly editing the registry can severely damage your system. Before making changes to the registry, we recommend that you back up any valued data on the computer.
The template size should be set on the basis of the available memory and the number of templates you are using. The default of TemplateCacheSize size is 31. You can increase the cache size if template access seems slow, or decrease the cache size if memory is low.
For better performance, it is recommended that you set TemplateCacheSize higher than the number of templates you usually use. If TemlateCacheSize is less than the number of templates you have, performance degrades as the number of templates increase. The TemplateCacheSize can be set to a maximum of 128.
Every time a cached template is used, the modification time of the template file is checked to see whether it needs to be refreshed. This is because the disk copy is newer than the cache copy.
Note
Template parameters and command properties are not cached.