Exposing multidimensional calculations through a relational database server
Accessing results of calculations on multidimensional data using relational database statements, such as SQL commands, involves a relational database server communicating with a multidimensional database server to cause the multidimensional database server to extract, and to perform calculations on, the multidimensional data. In response to a relational database statement in a language supported by the relational server, which includes an expression of an operation on the multidimensional data in a language supported by the multidimensional server, the multidimensional server extracts the required multidimensional data, performs the requested operation (e.g., an OLAP DML operation) on the data according to the specified expression, and provides results of the multidimensional operation to the relational database server. In one embodiment, the relational server passes information to the multidimensional server that uniquely identifies the location of the particular multidimensional data in the n-dimensional objects.
1. A method comprising the computer-implemented steps of:
a relational database server receiving a relational database statement that specifies a first expression and a second expression, wherein at least a part of said relational database statement is expressed in a first language supported by said relational database server;
wherein said first expression specifies to extract data from n-dimensional data objects stored in a database according to a multidimensional schema and present said extracted data as rows;
wherein said second expression includes a multidimensional expression that specifies a multidimensional operation, wherein said multidimensional expression is expressed in a second language supported by a multidimensional database server;
said relational database server causing said multidimensional database server to compute said first expression, said computation of said first expression returning to said relational database server:
(1) a set of rows, each row of said set of rows containing particular data derived from one or more n-dimensional objects, and
(2) a mapping that maps each row of said rows to a location, of the respective particular multidimensional data, in said one or more n-dimensional objects;
said relational database server causing said multidimensional server to compute second results for said second expression using said set of rows and said mapping resulting from the computation of said first expression as input to the second expression and returning said second results to the relational database server; and
wherein the method is performed by one or more computing devices.
2. The method of claim 1 , wherein said mapping includes data stored in a column of said set of rows.
3. The method of claim 1 , further comprising the computer-implemented step of:
generating, by said multidimensional database server, said particular data derived from one or more n-dimensional objects to include in said mapping.
4. The method of claim 1 , wherein said relational database statement conforms to Structured Query Language (SQL).
5. The method of claim 1 , wherein said first expression is a first function expression within said relational database statement that specifies a request for multidimensional data from n-dimensional data objects and said second expression is specified within a second function expression within said relational database statement that specifies an OLAP operation.
6. The method of claim 5 , wherein said first expression is OLAP_TABLE.
7. The method of claim 5 , wherein said second expression is OLAP_EXPRESSION.
8. A non-transitory computer-readable storage medium storing one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform steps of:
a relational database server receiving a relational database statement that specifies a first expression and a second expression, wherein at least a part of said relational database statement is expressed in a first language supported by said relational database server;
wherein said first expression specifies to extract data from n-dimensional data objects stored in a database according to a multidimensional schema and present said extracted data as rows;
wherein said second expression includes a multidimensional expression that specifies a multidimensional operation, wherein said multidimensional expression is expressed in a second language supported by a multidimensional database server;
said relational database server causing said multidimensional database server to compute said first expression, said computation of said first expression returning to said relational database server:
(1) a set of rows, each row of said set of rows containing particular data derived from one or more n-dimensional objects, and
(2) a mapping that maps each row of said rows to a location, of the respective particular multidimensional data, in said one or more n-dimensional objects;
said relational database server causing said multidimensional server to compute second results for said second expression using said set of rows and said mapping resulting from the computation of said first expression as input to the second expression and returning said second results to the relational database server.
9. The non-transitory computer-readable storage medium of claim 8 , wherein said mapping includes data stored in a column of said set of rows.
10. The non-transitory computer-readable storage medium of claim 8 , further comprising the computer-implemented step of:
generating, by said multidimensional database server, said particular data derived from one or more n-dimensional objects to include in said mapping.
11. The non-transitory computer-readable storage medium of claim 8 , wherein said relational data statement conforms to Structured Query Language (SQL).
12. The non-transitory computer-readable storage medium of claim 8 , wherein said first expression is a first function expression within said relational database statement that specifies a request for multidimensional data from n-dimensional data objects and said second expression is specified within a second function expression within said relational database statement that specifies an OLAP operation.
13. The non-transitory computer-readable storage medium of claim 12 , wherein said first expression is OLAP_TABLE.
14. The non-transitory computer-readable storage medium of claim 12 , wherein said second expression is OLAP_EXPRESSION.