Oracle Essbase 9 Implementation Guide- P79 pdf

Chapter 10 [ 375 ] Take a close look at the functions, most of them are intuitive as to their function and you will also notice a complete array of functions that are suspiciously similar to the column functions in relational SQL. Again, this is because an ASO database does not store the complete set of data like a BSO database does. ASO only physically stores the data at the lowest levels and is a lot like a relational database where you depend heavily on functions such as SUM, MAX, and ABS to massage the data as it is delivered to you. MDX function examples Here, we will show you the same data query function twice. One will be in the format used by the Essbase Calculation Script language and the other example will be in the MDX data query language. The reason for this is to illustrate how vastly different each language is. The @ANCEST function is a very commonly used function. In an Essbase database, where the data is stored at all levels, you can easily ask for the ancestor member. In an ASO database however, the data in most cases is dynamically calculated, so you have to ask for it in a different way so Essbase can interpret your request properly. • Essbase Calculation Script Syntax: @ANCEST (dimName, genLevNum, [ mbrName]) Example: @ANCEST(Product,2,Sales) • MDX Query Language Ancestor Example: ( Sales, Ancestor( Product.CurrentMember, Product.Generations(2) ) ) The command above assumes you are keying off of the member currently selected. What will be returned is the value of Sales from the ancestor of the member in the product dimension and the Generation level 2. This material is copyright and is licensed for the sole use by Paul Corcorran on 5th July 2009 8601 ave. p #1, , lubbock, , 79423 Download at Boykma.Com Essbase Analytics Option [ 376 ] MDX query syntax To make querying an ASO database more relational and SQL like, you can actually write your queries like you would in a relational database using SQL. Looking at the following examples, you can see that the SELECT statement is almost identical to that of a query written in SQL. Because the data is stored similarly, the query language is similar. That way, you won't forget when you're querying an Essbase BSO database or an Essbase ASO database. Typical MDX query structure: SELECT [<member_name>,[ <member_name>]] FROM [<Essbase_database_name>]] WHERE [<dimension_name.member_name> [, <dimension_name.member_name>]] Syntax: SELECT Sales,Stocks FROM EssCar WHERE Calendar Periods.June, Model Year.2010 Typical SQL Query Structure SELECT column_name>[, <column_name> ] FROM table_name WHERE value = value [and value = value] Syntax: SELECT Sales, Stocks FROM MARKET_INFO_TBL WHERE Month = June and ModelYear = 2010 Well, this should put you in a good place for querying an ASO database. The Essbase Technical Reference included and installed with the EAS on your client PC contains all of the information you need on the actual query functions and member set functions. As with everything else in this book, the only way you will get procient is to play around in the database. Executing an MDX query Now, here is a question that is begging to be asked. How do we execute an MDX query? This material is copyright and is licensed for the sole use by Paul Corcorran on 5th July 2009 8601 ave. p #1, , lubbock, , 79423 Download at Boykma.Com Chapter 10 [ 377 ] The answer is easy enough. You execute an MDX query in exactly the same fashion as you execute any MaxL statement. Remember, both DDL and MDX are really MaxL scripts. The only difference between MaxL DDL and MaxL MDX is the editor used through the EAS tool. In the previous screenshot, we showed you the MDX editor that you can access from the EAS tool by clicking on the Editors menu selection and then selecting MDX. When you are using the MDX editor, you have the same nice features as the other editors that are included in the EAS tool. It is through the editor that you can also execute your MDX statements. The other way to execute your MDX statements is through the command line prompt. This is exactly like you were shown earlier in this book for the MaxL DDL statements. Honestly, if it wasn't for the major outline differences between an ASO database and a BSO database, you could travel through your entire Essbase career and not really need the MDX piece of MaxL. Because the ASO database structure can actually be at least conceptually compared with a relational database more than a multidimensional database, it's a good idea to get friendly with MDX. This material is copyright and is licensed for the sole use by Paul Corcorran on 5th July 2009 8601 ave. p #1, , lubbock, , 79423 Download at Boykma.Com Essbase Analytics Option [ 378 ] Tuples and Sets A Tuple is a collection of members from different dimensions that represent a slice of data from the database. A tuple can contain one member from each dimension. A tuple should be wrapped in parentheses when written. In theory, each cell in the Essbase cube is dened by a tuple with one member from each dimension. A single member is also considered a tuple. A tuple is an easy way to describe a slice of data from an Essbase database. A correctly written tuple can contain very few actual words, but can describe a large amount of data. Here is an example of a tuple: (Total Market. United States) The tuple above will return all data at the Total Market level for the United States. Null Dimensions or Null member references are not valid tuples. Sets are an ordered collection of tuples. A set can be empty, have one tuple, or it can have more than one tuple. Duplicates of tuples are allowed. Sets are enclosed in curly brackets. Here is an example of a set: {C ALENDER PERIOD.2008}—denes one Tuple {CALENDER PERIOD.2008, CALENDER PERIOD.2007}—denes sets of two Tuples Pros and cons of ASO and BSO As you have seen earlier in the chapter, there are some differences between the ASO and the BSO. Even though there are differences, we would like the reporting output to be the same and the analyst who is running the report should not even know to which type of database he is connected. Let us take some time to look at a few of the pros and cons between these two types of databases. This material is copyright and is licensed for the sole use by Paul Corcorran on 5th July 2009 8601 ave. p #1, , lubbock, , 79423 Download at Boykma.Com Chapter 10 [ 379 ] Pros and cons of BSO The Essbase BSO is the original format of the Essbase database technology. The BSO is also the mainstay for Essbase as it offers robust, full-featured functionality. Here we will describe what we feel are some of the positive features of the BSO as well as some of the not so positive features for you. Pros Listed below are just a few high-level features that we feel makes the Essbase BSO a good choice: • Several databases stored in one application. • No reserved names for application and database names. • Account dimension supports all types of calculations and attribute members. • Calculation scripts are supported. • Uncomplicated write back ability. • Formulas are allowed in all dimensions with no restrictions. • Outline changes do not automatically clear data values, even if a data source is used to both modify members and load values. Therefore, incremental data loads are supported for all outlines. • Currency conversion is supported. Cons Listed below are a few high-level features that we feel you may need to be wary of when using the Essbase BSO: • For better performance, the outline dimensions must be dened as Dense or Sparse, based on data density, which can sometimes be difcult to get exactly right. • Database calculation—calculation script or outline consolidation. • Calculation order will need to be dened in the calc scripts and is predetermined in a default outline calculation. • Unrestricted write back ability which can be dangerous if care is not exercised. • No automatic update to values after data load. Necessary calculation scripts need to be specially executed, including any default calculations. • Sometimes requires large amounts of resources. This material is copyright and is licensed for the sole use by Paul Corcorran on 5th July 2009 8601 ave. p #1, , lubbock, , 79423 Download at Boykma.Com . Corcorran on 5th July 20 09 8601 ave. p #1, , lubbock, , 794 23 Download at Boykma.Com Chapter 10 [ 3 79 ] Pros and cons of BSO The Essbase BSO is the original format of the Essbase database technology you're querying an Essbase BSO database or an Essbase ASO database. Typical MDX query structure: SELECT [<member_name>,[ <member_name>]] FROM [< ;Essbase_ database_name>]] . and is licensed for the sole use by Paul Corcorran on 5th July 20 09 8601 ave. p #1, , lubbock, , 794 23 Download at Boykma.Com Essbase Analytics Option [ 378 ] Tuples and Sets A Tuple is a collection