8. An apparatus for optimizing an SQL query, comprising: (a) a computer having a memory and an electronic storage device coupled thereto, wherein the electronic storage device stores a relational database; (b) means, performed by the computer, for accepting an SQL query into the memory of the computer, the SQL query including a join operation for an outer table and an inner table stored in the relational database; (c) means, performed by the computer, for examining the query in the memory of the computer to determine whether the query includes a requirement for distinctiveness in one or more result columns of the join operation; (d) means, performed by the computer, for examining the query in the memory of the computer to determine whether one or more columns of the inner table are referenced in the query after the join operation is performed and whether each referenced column of the inner table is bound and is not involved in any length-sensitive expressions yet to be evaluated; and (e) means, performed by the computer, for performing an early-out join operation in place of the join operation when the query includes the requirement for distinctiveness and the referenced columns of the inner table are bound and are not involved in any length-sensitive expressions yet to be evaluated, the means for executing further comprising means for retrieving the inner and outer tables from the relational database stored in the electronic storage device, means for storing the inner and outer tables in the memory of the computer, means for scanning the inner table in the memory of the computer for a match for each row of the outer table, and means for terminating the means for scanning when the match is found.
8. An apparatus for optimizing an SQL query, comprising: (a) a computer having a memory and an electronic storage device coupled thereto, wherein the electronic storage device stores a relational database; (b) means, performed by the computer, for accepting an SQL query into the memory of the computer, the SQL query including a join operation for an outer table and an inner table stored in the relational database; (c) means, performed by the computer, for examining the query in the memory of the computer to determine whether the query includes a requirement for distinctiveness in one or more result columns of the join operation; (d) means, performed by the computer, for examining the query in the memory of the computer to determine whether one or more columns of the inner table are referenced in the query after the join operation is performed and whether each referenced column of the inner table is bound and is not involved in any length-sensitive expressions yet to be evaluated; and (e) means, performed by the computer, for performing an early-out join operation in place of the join operation when the query includes the requirement for distinctiveness and the referenced columns of the inner table are bound and are not involved in any length-sensitive expressions yet to be evaluated, the means for executing further comprising means for retrieving the inner and outer tables from the relational database stored in the electronic storage device, means for storing the inner and outer tables in the memory of the computer, means for scanning the inner table in the memory of the computer for a match for each row of the outer table, and means for terminating the means for scanning when the match is found. 12. The apparatus of claim 8, wherein the referenced column of the inner table is bound through a transitive equality predicate.