Performance Tuning Guide - EMC Community Network

Designing Reports
• Use database materialized views for reports with complex queries that require joins between
tables or calculations of the data. The database calculates views more effectively and quicker
than the report engine.
• Use Crystal Reports to create data analysis reports, such as pivoting, that require repetitive
filtering of data. For these types of reports, export report data to a .csv file and use tools such
as Microsoft Excel to generate pivot reports.
• Design performance sensitive reports in a separate dashboard so they do not affect response
time for the entire dashboard.
Modifying the number of records returned in a results
set
The number of records returned for a report can be increased or decreased by modifying the maxRows
parameter in the jdbc-config.xml configuration file. Controlling the number of records retrieved
is especially important for reporting, since large results sets can negatively affect system performance
and lead to an out-of-memory error. The BAM server returns 1,000 rows by default.
Note: When set to zero, the JDBC driver controls the maximum number of returned records.
Working across large data sets
To filter or sort across columns in different tables with large data sets, create a table that contains
columns from all the sorted or filtered tables. Create an index on that table. Performance improves at
the expense of storage and update overhead.
Using aggregation
Report summaries can be calculated from execution tables each time a report loads into the dashboard
or calculated in advance and saved in the aggregation table. Report summaries generated from
the aggregation table use less memory and provide shorter response time than report summaries
generated from execution tables, especially for execution tables containing thousands of rows of data.
Aggregation tables can be created for standard aggregation entities, custom entities, and business
data (SDTs and package objects).
Aggregating high volume data tables
Creating summaries of execution data in aggregation tables requires system resources and can
affect performance in high volume systems processing thousands of instances per day. In such
cases, aggregate report data every 5 minutes to strike a balance between providing real-time report
data, minimizing the system impact of generating reports directly from the execution tables, and
minimizing the system impact of running aggregation reports against large sets of report data.
EMC Documentum xCP 1.0 Performance Tuning Guide 61