Supporting set-level slice and dice in data warehouses

1. A method for implementing on-line analytical processing (OLAP) set-level slice and dice operations, comprising:

creating queries using structured query language on a computer and storing the queries on a storage medium;

utilizing an algorithm to rewrite the queries and implement OLAP slice and dice operations, wherein the algorithm:

rewrites the queries as ANDED set-level predicates with a remaining expression;

for at least one of the ANDED set-level predicates in the queries:

utilizes at least one selected from the group consisting of INTERSECT and UNION functions for query expressions with multiple set-level predicates;

utilizes at least one selected from the group consisting of CONTAINS, NOT CONTAINS, CONTAINED BY, NOT CONTAINED BY, EQUALS, and NOT EQUALS functions for rewriting the queries;

utilizes a DISTINCT function in combination with the UNION function on a group key; and

inserts the group key into a first temporary table;

for the remaining expression

inserts the group key into a second temporary table;

joins query expressions using the group key; and

uses an IN function with the group key; and

joins the set-level predicates from the queries to dimension tables corresponding to fact tables;

applying the algorithm to the queries to generate a result of the queries; and

outputting the result of the queries on a computer user interface.

2. The method of claim 1 , wherein the method rewrites queries having a single set-level operator.

3. The method of claim 1 , wherein the method rewrites queries having more than one set-level operator.

4. The method of claim 1 , wherein the method includes using at least one selected from the group consisting of INTERSECT and EXCEPT operators to create queries for set-level operators.

5. A system for implementing on-line analytical processing (OLAP) set-level slice and dice operations in a data warehouse, comprising:

a data warehouse user interface, including an input device, and computer monitor, permitting a user to create queries using structured query language on the data warehouse user interface and store the queries on a storage medium;

a data warehouse query engine hardware device including a computer processor, that utilizes an algorithm to rewrite queries, and implement OLAP slice and dice operations, wherein the algorithm

rewrites the queries as ANDED set-level predicates with a remaining expression;

for at least one of the ANDED set-level predicates in the queries in a plurality of predicates:

utilizes at least one selected from the group consisting of CONTAINS, NOT CONTAINS, CONTAINED BY, NOT CONTAINED BY, EQUALS, and NOT EQUALS functions for rewriting the queries;

utilizes at least one selected from the group consisting of INTERSECT and UNION functions for query expressions with multiple set-level predicates;

utilizes a DISTINCT function in combination with the UNION function on a group key; and

inserts the group key into a first temporary table;

for the remaining expression, the algorithm:

utilizes at least one selected from the group consisting of CONTAINS, NOT CONTAINS, CONTAINED BY, NOT CONTAINED BY, EQUALS, and NOT EQUALS functions for rewriting the queries;

inserts the group key into a second temporary table;

joins query expressions using the group key; and

uses an IN function with the group key; and

joins the set-level predicates from the queries to dimension tables corresponding to fact tables;

applying the algorithm to the queries to generate a result of the queries; and

a computer user interface outputting the result of the queries to a computer monitor.

6. The system of claim 5 , wherein the data warehouse query engine uses at least one selected from the group consisting of INTERSECT and EXCEPT operators to create queries for set-level operators.