Performance Tuning Guide - EMC Community Network

Designing the Application
Note: Composite indexes cannot be created across different types (simple process variables) or across
single value and repeating value attributes in the same type.
Note: Have a database administrator determine which columns of a table to index. Creating too
many indexes can cause update and insert statements to perform poorly.
See EMC Documentum Content Server DQL Reference Manual and EMC Documentum Content Server
Fundamentals for information on using make_index to create a composite index.
Minimizing fetch operations
During operations like opening a task, xCP extracts process variable attribute values and displays
the data on a form. For each process variable whose attribute displays on a form, xCP performs a
fetch operation for the process variable and its parent object. Design forms that require the fewest
number of fetch operations (involve the fewest number of process variables) as each fetch operation
affects performance.
For example, when using simple process variables only, a form with 50 fields performs 100 discrete
fetches. When using a single SDT to provide the 50 fields of information, the form performs only 2
discrete fetches, which results in far better performance.
Note: Forms that perform fewer than 60 fetches open in 2-3 seconds. Reducing the number of fetches
to less than 60 does not result in significant performance improvement.
Note: Content Server 6.6 provides for caching of the parent object after initial fetching. As a result,
the number of fetches (after the initial fetch) reduces by half (1 per process variable rather than 2
per process variable).
Note: Making a process variable invisible does not prevent an object fetch but it does result in a slight
performance improvement (Hiding unused variables, page 39).
Analyzing process variable usage (measuring fetches), page 75 provides information on measuring
the number of object fetches in your application.
Hiding unused variables
Process Builder provides the option to mark process variables as visible for manual activities. Making
a process variable invisible improves performance by reducing processing overhead associated
with the form. If no form fields use a process variable, hide the process variable by deselecting the
checkbox in the process variable definition (Figure 13, page 40).
EMC Documentum xCP 1.0 Performance Tuning Guide 39