1. A system comprising: one or more processors; a memory; a set of searchable items, stored in a plurality of repositories, wherein a searchable item is described by logical attributes; a set of physical attributes, associated with logical attributes, maintained by a search engine; a first mapping between a first set of logical attributes and the set of physical attributes, wherein the first set of logical attributes are associated with a first set of searchable items that belong to a first repository; a second mapping between a second set of logical attributes and the set of physical attributes, wherein the second set of logical attributes are associated with a second set of searchable items that belong to a second repository; wherein a first logical attribute of the set of logical attributes is mapped to a first physical attribute of the set of physical attributes; wherein a second logical attribute of the second set of logical attributes is mapped to said first physical attribute of the set of physical attributes; wherein said first logical attribute is semantically different from said second logical attribute; a set of indexes built on the set of physical attributes; wherein said set of indexes includes a first index built on said first physical attribute; wherein said first index includes index entries for searchable items of said first logical attribute and entries for searchable items of said second logical attribute; determining whether the first physical attribute is searched for by a query; in response to determining that said first physical attribute is searched for by the query, using said set of indexes to find searchable items from said set of indexes, and returning, at least in part, the searchable items associated with said first physical attribute.
1. A system comprising: one or more processors; a memory; a set of searchable items, stored in a plurality of repositories, wherein a searchable item is described by logical attributes; a set of physical attributes, associated with logical attributes, maintained by a search engine; a first mapping between a first set of logical attributes and the set of physical attributes, wherein the first set of logical attributes are associated with a first set of searchable items that belong to a first repository; a second mapping between a second set of logical attributes and the set of physical attributes, wherein the second set of logical attributes are associated with a second set of searchable items that belong to a second repository; wherein a first logical attribute of the set of logical attributes is mapped to a first physical attribute of the set of physical attributes; wherein a second logical attribute of the second set of logical attributes is mapped to said first physical attribute of the set of physical attributes; wherein said first logical attribute is semantically different from said second logical attribute; a set of indexes built on the set of physical attributes; wherein said set of indexes includes a first index built on said first physical attribute; wherein said first index includes index entries for searchable items of said first logical attribute and entries for searchable items of said second logical attribute; determining whether the first physical attribute is searched for by a query; in response to determining that said first physical attribute is searched for by the query, using said set of indexes to find searchable items from said set of indexes, and returning, at least in part, the searchable items associated with said first physical attribute. 4. The system of claim 1 wherein: a third logical attribute of the set of logical attributes is mapped to a second physical attribute; a fourth logical attribute of the set of logical attributes is mapped to said second physical attribute; wherein said first logical attribute is semantically different from said second logical attribute and the first logical attribute and the second logical attributes are assigned to to different nodes in the hierarchy.