Performing an efficient implicit join of multiple mixed-type records

[0004]The present invention introduces techniques for efficiently joining multiple mixed-type records retrieved from a hierarchical database. Records are retrieved from a hierarchical database. The retrieved records may be relevant to a query submitted by a client. Each of the retrieved records is categorized into a record type and has a unique identifier field. A record map is populated by iterating over the retrieved records. The record map associates each identifying value included in one or more unique identifier fields with data from each record having the identifying value. Moreover, for each record, a flag in the record map corresponding to the record type of the record and is associated with the identifying value included in the unique identifier field of the record is set. Inner joins and outer joins can then be performed using the contents of the record map. The query submitted by the client can then be answered based on the result of any inner joins and outer joins thus performed. Notably, the query submitted by the client may be processed using a single pass through the database. Thus, resource requirements for processing the query and any joins included therein are beneficially reduced.

A database may store quantities of data which are potentially very large.