You may change the Java settings to enhance the performance of the Web Portal's all around functionality including the Web Portal search. Here are the steps:
Launch the shortcut "Configure Server as a Service" in the Start menu on the Application Server. Alternatively, go into the Windows services and then double-click the service for the web portal.
A window 'CA ERwin Web Portal Service Properties' will open.
Click the tab 'Java'.
The default initial memory pool is 512 and the default maximum memory pool is 1024.
Please change the Initial Memory Pool to 4000 and the Maximum memory pool to 5500.
Then restart the web portal service.
NOTE: r9.64.1 Web Portal introduced the 64-bit OS version and that optimizes the memory usage on a 64-bit OS Windows machine. Hence, if you are using the Web Portal r9.64.1 or later version, then you do not need to adjust the java memory as above. Instead, please consider adding more RAM memory to the machine that hosts your Web Portal.