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Characteristics of Ordered (OLAP) Analytical Computations.

Written by admin in Thursday, August 23rd 2007 under IT

1. One of the useful features in Ordered Analytical Computation is to produce/define data sets or data subsets dynamically. This is done by the usage of the OVER () phrase (detail later). This OVER () feature can be used with all the aggregate functions too.

2. Introducing the usage of QUALIFY Clause: If there is a need to eliminate or extract rows based on the certain condition after the partition, use this clause.

3. DISTINCT Clause in NOT allowed Analytical Computations.

4. Ordered (OLAP) analytical functions are permitted in the following database objects:• Views• Macros• Derived tables• INSERT INTO-SELECT FROM.

5. Ordered (OLAP) analytical functions are not permitted in sub queries. But note that if you are just using aggregate functions, then it is allowed.

6. Ordered (OLAP) analytical functions are even not permitted in WHERE clauses. Same is the case with aggregate functions.

7. Ordered (OLAP) analytical functions do not support CLOB or BLOB data types.

8. If you want to sort the result set, by a column present in the partition clause, then mind that you have to use the ORDER BY again after the FROM clause. Only using within the partition specification would not sort the result set.

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