Oracle9i OLAP User's Guide Release 2 (9.2) Part Number A95295-01 |
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OLAP_TABLE Function, 4 of 6
Creating type definitions that are used by the OLAP_TABLE
function involves:
Each object type represents a row in a table. When mapping analytic workspace structures to object types, typically, you do not define one object type for each analytic workspace structure. Instead, you map many analytic workspace structures to just a few objects:
For a more complete discussion of the data warehouse designs that you can mimic in your design, see "Data Structures in Relational and Multidimensional Data Stores".
For each object, you need to identify the attributes that correspond to the columns of the table. To do this, you first need to determine if you want to support the use of WHERE
clauses when selecting the data. Only those attributes (table columns) that appear in the limit-map
parameter of the OLAP_TABLE
function can be referenced in a WHERE
clause.
Typically, you will want to support the use of WHERE
clauses. In this case, you need to determine the format of the limit-map
parameter in order to determine the columns of each table. The columns of each table must correspond exactly to the columns specified in the limit-ma
p parameter. For the syntax of the limit-ma
p parameter, see "Syntax: OLAP_TABLE Function".
To create the type definitions that define the analytic workspace data as a table of objects take the following steps:
CREATE TYPE object-name AS OBJECT ( column-first data-type, column-next data-type, column-last data-type);
CREATE TYPE table-name AS TABLE OF object-name;
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