Search Service Factors

If your portal site will offer a Search channel, you need to include sizing factors for the Search Engine in your sizing calculations. Search Engine sizing requirements depend on the following factors:

• The size of index partitions on the active list of the index directory

  Partition size is directly proportional to the size and number of indexed and searchable terms.

• Average disk space requirement of a resource description (RD)

  To calculate this, use this formula:

  average disk space requirement =
  database size / number of RDs in database

  The average size adjusts for variations in sizes of RDs. A collection of long, complex RDs with many indexed terms and a list of short RDs with a few indexed terms require different search times, even if the complex RDs have the same number of RDs.

  RDs are stored in a hierarchical database format, where the intrinsic size of the database must be accounted for, even when no RD is stored.

• The number of concurrent users who perform search-related activities

  To calculate this, use this formula:

  number of concurrent users / average time between search hits

  Use the number of concurrent users value calculated in Concurrent Users.

• The type of search operators used

  Types of search functions include basic, combining, proximity, passage and field operator, and wildcard scans. Each function uses different search algorithms and data structures. Because differences in search algorithms and data structures increase as the number of search and indexed terms increase, the type of search function affects times for search result return trips.