Resolution
These rules appear similar, but they have very dissimilar methods in implementation. They are both designed to help identify key pieces of iinformation about an identity and to gather and link that iinformation upon an Identity Cube.
A BuildMap rule literally builds a map of data read from an account connector and builds a map of that data into the repository for use. BuildMap rules are normally used with delimited file connectors, and we do supply some sample rules standard within the Access Governance Suite deployment package itself. These samples are found under $SPHOME/WEB-INF/config/examplerules.xml. BuildMaps are sometimes used across applications when the data is supplied in a specific agreed upon and pre-defined format, but these rules may have to be unique to each application. BuildMap Rules do expect data to be delivered in a consistent and constant format. Changes to format will result in problems with a BuildMap Rule delivering the data in a consistent manner.
Quite literally stated, the BuildMap Rule does what its name implies - it builds a map of the data in the format it is expected to arrive in and stores the data into the repository within that format.
Correlation rules are used to find identities and then add interesting new iinformation to an Identity Cube XML object. An example of a Correlation Rule is a Manager Correlation Rule, there is a sample of this within the examplerules.xml file shipped within Access Governance Suite. This rule has a very explicit purpose: it is a rule called to help locate the mapped manager field and map that account iinformation to an identity. There are other examples of using correlation as well; the possibilities are limitless. The thing to remember with a correlation rule is that you are locating key iinformation that will help locate iinformation that is relevant to an identity and map that relationship iinformation.
Correlation Rules are re-usable and can be expressed across many applications. Correlation Rules are used during account aggregations to gather and store nformation on Identity objects.