Directory catalogs on servers compared to directory assistance for individual Domino® Directories

A server can do lookups directly in a secondary Domino® Directory using directory assistance, or can do lookups in a directory catalog that aggregates information from the secondary Domino® Directory.

There are several advantages to servers doing lookups in a directory catalog, rather than in individual Domino® directories:

• A server can look up information more quickly by searching one directory database rather than multiple databases -- the more secondary directories you aggregate in a directory catalog, the greater this advantage.
• If there are multiple Person documents with the same name in one directory or across directories, you can remove the duplicates from the directory catalog. The Dircat task then aggregates the first Person document with the name that is encountered, which avoids name ambiguity problems, for example, the Router failing to deliver mail because it finds more than one occurrence of a name.
• A directory catalog excludes most or all Domino® administration information that is part of a Domino® Directory that is not of interest to users. You can also filter out other information in a Domino® Directory from a directory catalog. For example, an administrator can exclude specific fields, or use a selection formula to exclude documents that do not match specified criteria.
• Notes® client users without condensed directory catalogs can browse one directory, rather than multiple, individual secondary Domino® directories.

The advantage to doing lookups in individual secondary Domino® directories is there is no need to build, maintain, and replicate a directory catalog. Instead you create and replicate only a small directory assistance database.

Setting up servers to use directory catalogs is useful for organizations that use multiple Domino® Directories, for example, organizations with multiple Domino® domains.