1. A method of providing for mapping between data formats, comprising: accessing a first data format, said first data format includes objects, said objects include attributes and wherein one or more of said attributes are multi-valued; accessing a relational database format that uses tables, said tables store data for said attributes; classifying said attributes based on column and table in said relational database format, wherein classifications are used to translate between the data formats and each classification is translated differently; creating a customized mapping catalog for said relational database format based on said classifications, said mapping catalog maps said attributes of said objects to said tables of said relational database format and identifies relationships between tables of said relational database; storing the mapping catalog for use in translating subsequent data access requests; receiving a request to access data for a first attribute, wherein the request includes the first attribute and a filter for accessing the data for the first attribute; determining a relational database from a plurality of data stores to service said request, wherein the plurality of data stores comprises the relational database and at least one LDAP directory and wherein determining the relational database from the plurality of data stores comprises comparing the filter for accessing the data for the first attribute to a partitioning expression for each of the data stores and defining data stored in that data store, wherein the partitioning expression is in an LDAP filter format and comparing the filter for accessing the data for the first attribute to the partitioning expression for each of the data stores comprises determining whether the filter for accessing the data for the first attribute and the partitioning expression overlap at least in part by performing a partition compare function using said filter and the partition expressions to determine whether said filter overlaps with one of the partition expressions if said filter and said one of the partition expressions are both simple expressions and performing said partition compare function by treating said filter as an input partition expression and treating the partition expressions as an input filter in order to determine whether said filter overlaps one of the partition expressions if said one of the partition expressions is a composite expression; accessing the stored mapping catalog based on determining the relational database; and translating at least a portion of the request based on the stored mapping catalog.