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Overview
AWM 11g is a tool for creating, developing, and managing
multidimensional data in an Oracle 11g data warehouse. With this easy-to-use
GUI tool, you create the container for OLAP data, an analytic workspace (AW),
and then add OLAP dimensions and cubes.
In Oracle OLAP, a Cube provides a convenient way of collecting
stored and calculated measures with similar characteristics, including dimensionality,
aggregation rules, and so on. A particular AW may contain more than one cube,
and each cube may describe a different dimensional shape. Multiple cubes in
the same AW may share one or more dimensions. Therefore, a cube is simply a
logical object that helps an administrator to build and maintain data in an
AW.
After creating cubes, measures, and dimensions, you map the
dimensions and stored measures to existing star, snowflake, and normalized relational
sources and then load the data. OLAP data can then be queried with simple SQL.
The source data for this tutorial the OLAPTRAIN schema. OLAPTRAIN
is a star schema that was sourced from a base transactional system which contains
data for a fictional electronics store. The star schema contains “dimension”
tables, which describe the relationships in the data, and “fact”
tables, which contain the metrics used to measure performance.
The following are the tables, intended for analysis, that
previously have gone through the ETL (Extraction, Transformation, and Loading
of heterogeneous data) process:
Table
Description
CHANNELS
Table containing distribution channels for customers purchases.
CUSTOMERS
Table that show who purchased products, and where products are sold for
the Geography dimension.
PRODUCTS
Table containing products that are sold by the company.
TIMES
Table containing time periods when products were sold.
SALES_FACT
Stores purchases in dollars, quantity, and price, by channel of distribution,
product item, day, and customer.
Designing a Logical Data Model
After examining the relational tables, the available levels,
hierarchies, and attributes for each dimension are identified. In addition,
the required stored and calculated measures are identified as part of the business
requirements definition process. The resulting logical model becomes the design
for the OLAP data model.
Identifying Dimensions
Using the source data tables as the primary input, the following
dimensions have been identified as requirements for the OLAP data model:
Channel
Geography
Product
Time
Identifying Levels
When designing your OLAP model, you also determine the level
of summarization that you want to load into your cube. You may not necessarily
want to replicate the data in your source as a cube. You can always query the
detail data (since all of the data is in the Oracle database), by joining the
cube to the fact table.
Your business requirements for summary management and analysis
purposes should define the lowest level of detail for each dimension in the
OLAP cube. You can load data into the cube at any level. After performing a
business requirements analysis, the following the levels of summarization within
each dimension have been identified as part of the OLAP data model:
Channel dimension
has two classes of distribution channels: Direct and Indirect. The children
of these two values are the lowest level of detail and will be grouped
in the Channel level. From the order of highest level of summarization
to the lowest level of detail, levels will be: All Channels, Class,
and Channel.
Geography
dimension reflects how company performs customer and geographic
analysis along regions. Although the CUSTOMERS dimension table contains
the following levels of detail: Region > Country > State-Province
> City > Customer, the levels of summarization required for geographic
analysis in the OLAP system will be (highest to lowest): All
Regions, Region, Country, and State-Province.
Product dimension will
have six levels. These levels reflect the same levels of detail in the
source data. From highest to lowest, the OLAP levels are: All
Products, Department, Category, Type, Subtype, and Item.
Time dimension will have
four levels (highest to lowest): All Years, Calendar Year, Calendar
Quarter, and Month. Data is available for the
years 2005–2007.
Within each dimension, notice that an "All" (Total)
level is added as the highest level of summarization. Adding this highest level
provides additional flexibility as application users analyze OLAP data.
Identifying Hierarchies
Hierarchies organize the levels within each dimension. To
identify hierarchies, you group the levels in the correct order of summarization
and in a way that supports the identified types of analysis. You can orgainize
levels into any number of hierarchies for each dimension.
In this OLAP data model, only one hierarchy is required for
each dimension. The hierachy levels are designed as shown in the table above.
Identifying Measures
Analysis requirements include both stored and calculated
measures. Two of the measures are acquired from the fact table, and the remaining
measures are created and managed as OLAP calculations:
An analytic workspace is a container for multidimensional
data objects and procedures written in OLAP DML. It is created using the AWM
tool. Perform the following steps:
1.
Launch AWM 11g either by double-clicking <your_path>\awm\bin\awm11.1.0.7.0A.jar,
or from your desktop shortcut.
2.
Right-click Databases and select Add Database to tree.
3.
Enter Oracle11g in the Description field and <hostname>:1521:<SID>
in the Connection Information field and click Create.
4.
Click the Plus sign (+) next to Oracle11g.
5.
Enter olaptrain as the Username and oracle
as the Password. Then click OK.
Dimensions are lists of unique members that identify and categorize
data. They form the edges of a cube, and thus the measures within the cube.
Dimensions may contain levels, hierarchies, and attributes. You may define levels
at the same time that create a dimension, or you may define the levels later.
You can define dimensions either as 'User' or as 'Time' dimension
type. Business analysis is performed on historical data, so fully defined time
periods are vital. For a Time type dimension, your source data must have columns
for period end dates and time span. These required attributes support OLAP time-series
analysis, such as comparisons with earlier time periods. If this information
is not available, then you can define Time as a normal dimension, but it does
not support time-based analysis.
1.
Right-click the Dimensions folder and select
Create Dimension.
2.
At the default General tab in the Create Dimension dialog
box, enter CHANNEL as the name and select User Dimension
as dimension type.
3.
In the Levels tab, enter the following three levels:
ALL_CHANNELS
CLASS
CHANNEL
Note: the Label and Description fields are auto-filled
4.
In the Implementation Details tab, select Use
Keys from Data Source.
Then, click Create.
5.
Your dimension, and its associated levels, have been
created.
For business analysis, data is typically summarized at various
levels. For example, your database may contain daily snapshots of a transactional
database. Days are thus the base level. However, you might summarize this data
at the monthy, quarterly, and yearly levels.
A hierarchy is a logical structure that uses ordered levels
as a means of organizing data. It can be used to define data aggregation; for
example, in a time dimension, a hierarchy might be used to aggregate data from
the month level to the quarter level to the year level. A hierarchy can be used
to define a navigational drill path, regardless of whether the levels in the
hierarchy represent aggregated totals.
Dimensions can have one or more hierarchies. If you define
multiple hierarchies, one of them must be defined as the default hierarchy.
1.
Right-click the Hierarchies folder, then select Create Hierarchy.
2.
In the Create Hierarchy window, enter SALES_CHANNEL
as the name. Click the Add All (>>) tool to select all the levels
and click Create.
3.
The new SALES_CHANNEL hierarchy appears as an item in the Hierarchies
folder.
Attributes provide information about the individual members
of a dimension. They are used for labeling data displays and selecting data.
All dimensions are created with long and short description attributes. Time
dimensions also have time-span and end-date attributes. In addition, you can
create your own user attributes
In this section, you create a CHANNEL_TYPE attribute, and
also review the description attributes for the CHANNEL dimension you just created.
Perform the following steps:
1.
Rick-click the Attributes folder, then
select Create Attribute.
2.
In the Create Attribute dialog, select or enter the following:
a. Name = CHANNEL_TYPE
b. Attribute Type = User
c. In the “Apply Attributes to” box:
Drill on the Channel dimension.
Deselect the Channel dimension check box.
Select only the CHANNEL level check box (the lowest
level).
Note: The Channel Type attribute only applies to the lowest level in
the Sales Channel hierarchy.
The Create Attribute dialog box should look like this:
Click Create.
3.
Expand the Attributes folder to view the Channel
dimension attributes.
4.
Select the LONG_DESCRIPTION attribute. In the
right-hand pane, notice that description attributes are defined for
all levels in the hierarchy, in contrast to the user attribute that
you just created..
After creating OLAP data objects, you map them to tables and views in Oracle
Database. You map the key column in the dimension table to the Member attribute
in the OLAP dimension. In addition, you map the appropriate attribute columns
in the dimension table to the associated OLAP dimension attributes.
Afterward, you can load data into your analytic workspace
using the Maintain Analytic Workspace wizard.
1.
Expand the CHANNEL dimension and click Mappings.
Result: Two panes appear to the right: of the navigator -- the Schemas
pane, and the Mapping pane. In the Table Mapping view (right-hand pane),
the Source Column fields are initially blank, as shown here:
2.
Ensure that Star Schema is selected
as the Type of Dimension Table, as shown in the previous step.
3.
In the source schema pane, expand OLAPTRAIN
> Tables > CHANNELS. Then, drag
the source columns from the Schema pane to the Mapping pane for the
CHANNEL and CLASS levels as shown in the picture below.
The ALL_CHANNELS level in the hierarchy does not contain a source
data column. For "All/Total" hierarchy levels, you can enter
constants or single row SQL functions. Enter the following constants
for the ALL_CHANNELS level (single quotes are required for text literals):
Member = ‘ALL_CHANNELS’
Description attributes = ‘All Channels’
The resulting mapping should look like this:
Note: The "All/Total" value ensures that there is a single
node at the top of the hierarchy that will be the summary of the data
for that dimension.
4.
In the lower right corner of the mapping pane, click Apply.
Result: The Channel dimension is ready to have data loaded. Although
you could load the dimension data now, you will perform this step later
in the tutorial.
The template feature in Analytic Workspace Manager saves the
definition of the OLAP data objects as an XML file. Using a saved template,
you can create a new analytic workspace, dimension, cube, and measure exactly
like an existing object, with or without mappings. Templates do not include
the data, only the definition of the object.
Templates allow you to:
Share analytic workspace designs with other users.
Transfer object definitions to other schema
or instances.
Persist object definitions outside database.
Place object definitions in source control.
In this section, you create three dimensions, GEOGRAPHY, PRODUCT
and TIME from previously saved templates. Perform the following steps:
1.
Right-click the Dimensions folder, then select
Create Dimension From Template.
2.
At the Create Dimensions From Template dialog box, locate
the ...\templates directory, where you installed the olaptrain template
files.
For example: c:<your_path>\templates
Then, select GEOGRAPHY.XML in the templates directory and click
Create.
3.
The new GEOGRAPHY dimension appears under the Dimensions
folder. Drill on Levels, Hierarchies,
and Attributes to view its elements.
4.
To create the PRODUCT dimension, right-click the Dimensions
folder, then select Create Dimension From Template, as you did
previously in step 1.
5.
At the Create Dimensions From Template dialog box, locate
the PRODUCT.XML file and click Create.
6.
The new PRODUCT dimension appears under the Dimensions
folder.
7.
Now, create the TIME dimension by right-clicking the
Dimensions folder and selecting Create Dimension From Template.
8.
At the Create Dimensions From Template dialog box, locate
the TIME.XML file and click Create.
Result: The new TIME dimension appears under the Dimensions folder.
9.
In the navigator, drill on TIME >
Attributes.
Notice that there are two special attributes -- END_DATE and TIME_SPAN
-- have been created for the TIME dimension. Since this dimension was
defined as a "Time" type, these attributes are automatically
created. They must be mapped to apppropriate source data columns for
certain OLAP time series analysis features to be enabled. You will leverage
these attributes when you create time series calculations later in this
tutorial.
10.
The Geography, Product and Time templates all included
mappings. To view the mappings for the Time dimension, click Mappings
under TIME in the navigator.
As with the other the "All/Total" level in the hierarchy
is mapped to either constants or single-row SQL functions.
You can examine the mappings for any of these dimensions by clicking
on the Mappings tab under the dimension node in the navigator.
In Oracle OLAP, a Cube provides a convenient way of collecting
measures of the same dimensionality. Therefore, a cube is simply an object that
helps an administrator to build and maintain an AW.
Cubes aid in the definition of measures with common characteristics,
including the following:
The edges of a Cube are defined by its
dimensions. If multiple measures have the same dimensionality, it is
likely that they will be defined in the same cube..
Measures that share sparsity patterns and
aggregation rules are commonly defined in the same Cube.
Measures in the same Cube have the same
relationships to other logical objects and can easily be analyzed and
displayed together.
A particular AW may contain more than one
Cube, and each cube may describe a different dimensional shape.
Multiple Cubes in the same AW may share
one or more dimensions.
For example, sales data can be organized into a cube, whose
edges contain values from the channel, geography, product, and time dimensions
and whose body contains measures that might include dollar sales, unit sales,
and a range calculated measures based on sales and quantity sold.
Perform the following steps to create a cube that will be
used to organize a variety of sales measures:
1.
Right click the Cubes folder, then click Create
Cube.
2.
In the General tab of the Create Cube window, specify
the following:
a. Name: SALES_CUBE
b. Use the Add tool (>) to selected dimensions in the following
order:
CHANNEL
TIME
GEOGRAPHY
PRODUCT
Result: the Create Cube window should look like this:
Notes: The order in which the dimensions are listed in a cube may affect
performance because it determines the way the data is stored on disk.
In general, when you dimension a cube, the first dimension in a cube
has the fewest number of dimension members, and the last dimension has
the largest number of dimension members. This is the case in the OLAPTRAIN
schema.
3.
Select the Storage tab. Accept the
default option to Use compression, and then enable
the Sparse option for all dimensions, as shown here
Notes:
What is Sparsity? When there are a large number of empty cells in
a cube, the cube is said to be “sparse.” This is very
common in dimensional data models. Most commonly, all dimensions are
marked as sparse. When one or more dimensions as marked as sparse,
OLAP creates a special index for the cube that automatically manages
sparsity.
The Compression feature can be used to significantly reduce the
size of cubes and improve performance of both data loads and queries.
Since most dimensional data is sparse, the Compression option is selected
as a default.
4.
Select the Aggregation tab. Then, in
the Precompute sub-tab, specify a value of 30 for Cost-based
aggregation, as shown here:
Notes:
Cost-based aggregation is new feature for Oracle 11g OLAP. You
can use this feature if you select compression for your cube. Specify
a percentage value and the database will precompute and store the
most costly aggregate values based on your input.
Using a setting of 30 causes a larger percentage of cube data to
be aggregated and stored than the default setting of 20.
5.
In the Partitioning tab, select the Partition
cube option. (The Dimension, Hierarchy, and Level options are
enabled.)
Then, select the following settings to specify partitioning on the
Time dimension at the Year level:
a) Dimension = TIME
b) Hierarchy = CALENDAR
c) Level = CALENDAR_YEAR
6.
At the bottom of the Create Cube dialog
box, click Create.
Result: the SALES_CUBE node appears in the navigator under Cubes.
You can create two types of measures in a cube: Stored (or
Base) measures, and Calculated measures. Every measure that belongs to a particular
cube shares the characteristics that were defined for the cube.
Stored Measures
Base measures store the facts collected about your business.
When you create base measures in your OLAP data model, you will map them to
source data just as you have done with dimensions.
Calculated Measures
One of the powerful features of the Oracle OLAP technology
is the ability to efficiently and easily generate business calculations of
data held in the database. In any OLAP implementation, the number of calculated
measures greatly exceeds the number of stored measures.
OLAP calcuated measures are derived from base measures or
other calculated measures.These calculations are computed dynamically as users
query the data. Calculations are automatically exposed as columns in a cube
view – making it very easy for users to leverage the rich analytic functionality
through very simple SQL.
AWM makes it very easy to define calculated measures using
a graphical Calculation Builder. The Calculation Builder contains pre-defined
examples for many common business calculation types. You select the calculation
type you want, and then modify the example to create exactly the calculation
that you need.
In this section, you will create two stored measures and
ten calculated measures. Three of the calculated measures are created using
the Calculation Builder, and seven are created using XML template files.
1.
In the navigator, drill on SALES_CUBE.
Then, right-click on the Measures folder and select
Create Measure.
2.
At the Create Measure dialog box, enter SALES
as the name and click Create.
3.
Using the same techniques described in steps 1 and
2, create a second measure named QUANTITY.
In the navigator, drill on Measures. You should see
the following:
4.
In the navigator, right-click on the Calculated
Measures folder and select Create Calculated Measure.
5.
In the Create Calculated Measure window, enter or select
the following:
a) Name = SALES_YTD (the Name field is automatically
all caps, and the Label and Description fields are auto-filled)
b) Calculation Type = Period to Date
c) In the Calculation inputs section, select the following:
First hyperlink = Ancestor At Level
Result: A new hyperlink appears next to Ancestor At Level hyperlink
Second hyperlink = TIME.CALENDAR_YEAR
Result: The Create Calculated Measure window should now look like this:
d) Click Create.
6.
Drill on the Calculated Measures node.
Result: The SALES_YTD calculation appears.
7.
Create a YTD calculation for the
prior year. This facilitates year over year comparisons.
Right-click the Calculated Measures folder again, then select
Create Calculated Measure. In the Create Calculated Measure window,
enter or select the following:
a) Name = SALES_YTD_PY
b) All Label and Description boxes = Sales Ytd Pr Year
c) Calculation Type = Parallel Period
d) In the Calculation inputs section::
Click the SALES hyperlink (this is the second hyperlink):
Result: The Select Measure window appears.
Select SALES_YTD (as shown below) and then click
OK.
Result: The Calculation updates with the selected measure.
Click the TIME.CALENDAR.ALL_YEARS hyperlink and select TIME.CALENDAR.
CALENDAR_YEAR from the list, as shown here:
e) Click Create.
Result: The SALES_YTD_PY calculation appears below the Calculated Measures
node in the Navigator.
8.
Create a third calculation that measures the percent
change in Year-To-Date sales when compared to the previous year. Right-click
on the Calculated Measures folder and select Create
Calculated Measure.
9.
In the Create Calculated Measure window, enter or select
the following:
a) Name = SALES_YTD_PY_PCT_CHG
b) All Label and Description boxes = Sales Ytd Pr Yr Pct Chg
c) Calculation Type = Percent Difference From Parallel Period
d) In the Calculation inputs section, click the SALES
hyperlink.
e) In the Select Measure window, select SALES_YTD
and click OK.
f) Click the TIME.CALENDAR.ALL_YEARS hyperlink and
select TIME.CALENDAR. CALENDAR_YEAR from the list.
The calculation should now look like this:
g) In the Expression field, multiply the equation by 100 by adding
the following syntax to the beginning of the expression: 100
*
The expression should now look like this:
Note: This additional syntax will cause the calculation to display
percentage figures in whole numbers.
h) Click Create.
Result: The Sales Cube now contains the following measures:
10.
Next, create a calculated measure using an XML template.
Right-click on the Calculated Measures folder and select
Create Calculated Measure from Template.
11.
In the Create Calculated Measure from Template window:
a. Navigate to the ...\templates\calcs directory, where you installed
the olaptrain template files.
For example: c:<your_path>\templates\calcs
b. Then, select SALES_PY.XML
c. Click Create.
Result: The calculation appears in the navigator.
12.
Select the new calculation in the navigator.
Result: The Sales Prior Year calculation definition appears in the
right-hand pane, as shown below:
13.
Repeat steps 10 and 11 to create eight more calculations
using the following XML files:
SALES_PY_PCT_CHG.XML
SALES_PP.XML
SALES_PP_PCT_CHG.XML
SALES_ RANK_PROD_LVL.XML
SALES_ RANK_PROD_PRNT.XML
SALES_SHARE_PRNT_PROD.XML
SALES_SHARE_TOT_PROD.XML
HOW_IS_SALES_YTD.XML
14.
Select the Calculated Measures node
in the navigator to display the list of calculated measures in the cube.
All of your measures have been created.
15.
Click the How Is Sales Ytd calculated
measure in the navigator to view the definition of the calculation,
as shown here:
Notes:
The Calculation Type is Expression. This special
calculation type allows the OLAP data model developer to create a
custom calculation by entering the appropriate OLAP calculation syntax
in the Expression box.
In this example, the syntax includes a “CASE” statement
that evaluates the series of conditions and returns the first expression
that matches the condition. The CASE statement is designed to return
a text value describing the performance of the current Sales YTD compared
to last year.
You will used this, and other calculated measures later in this
tutorial.
You can learn more about creating OLAP calculations by attending
the Oracle University Oracle Database 11g: OLAP Essentials
inClass course. For a description of this course, see More
Information at the end of this tutorial.
After creating an OLAP cube, you map it to relational data
sources in Oracle Database. When mapping the cube, drag the appropriate source
data column to the associated field for the OLAP cube element.
You map the following fields:
The stored measures that are defined
within the cube.
The lowest level of detail for each dimension
hierarchy.
The Join Condition field. This field associates
the foreign key (fk) column from the fact table to the primary key (pk)
column from the dimension table.
Afterward, you can load data into your analytic workspace
using the Maintain Analytic Workspace wizard.
1.
Click the Mappings node under SALES_CUBE
Ensure that the Table Mapping View is enabled.
2.
In the source schemas pane, drill on OLAPTRAIN
> Tables.
3.
Locate and use the following tables:
SALES_FACT
CHANNELS
CUSTOMERS
PRODUCTS
TIMES
Drag the appropriate columns from each source table to the associated
SALES_CUBE Source Column fields, as shown in the image below.
Notes: When mapping the Join Condition for each dimension:
First, drag the foreign key column from the fact table to the Source
Column field.
Then, drag the primary key column from the dimension table to the
Source Column field.
The equal sign (“=”) is automatically inserted after
you drag the second column into the Source Column field.
When the mapping is complete, your source column results should look
like this:
In an extension of the Materialized View capabilities
for Oracle Database 11g, OLAP cubes can be represented as a cube-organized materialized
views (Cube MVs). The query optimizer automatically recognizes when an existing
Cube MV can and should be used to satisfy a SQL summary request. A Cube MV represents
a significant summary space, and benefits include both ease of manageability
and improved query performance.
If your OLAP system requirements do not include a need for
summary management of exiting SQL-based BI applications, then you can skip this
optional task.
Notes:
If you chose to enable query rewrite,
supporting cube MV objects are automatically created and managed by
the Oracle Database.
Before you can enable materialized views
for the cube, you must first map the cube.
To enable query rewrite and MV refresh for your OLAP cube,
peform the following steps.
1.
In the navigator, click SALES_CUBE.
2.
In the right pane, click the Materialized Views tab
and select the following options:
Enable Materialized View Refresh of the Cube
Enable Query Rewrite
Notes:
MV Refresh
If you select Enable MV Refresh, you also specify the refresh method
and mode for the cube. Cube MV refresh methods include, Complete,
Force, and Fast.
The default Refresh Mode is On Demand.
Query Rewrite
If you select Enable Query Rewrite, supporting cube MV objects
are automatically created by the database when you click Apply.
When a Cube is enabled for query rewrite, the associated Dimensions
are automatically enabled for MV refresh as well.
3.
Accept the default settings for all other options, and
then click Apply.
Result: the following information box appears:
When the information box closes, cube MVs are enabled and ready for
use by the Materialized View subsystem.
Note: For more information on enabling and troubleshooting Query Rewrite
to Cube MVs, see this white
paper.
The Maintenance Wizard loads and aggregates the data in
a single step. You can load all mapped objects in the analytic workspace,
or individual dimensions and measures. You can also choose to run the job immediately,
enter it in the Oracle Job Queue, or save it as a SQL script.
By default, when you load data to a cube, the dimensions of
that cube are also processed. If you have already loaded dimension data, you
can specify only to load measure data.
In the following steps, you load all data for the cube and
run the job immediately. Then you view the data in AWM.
1.
In the navigator, right-click on SALES_CUBE
and then select Maintain Cube SALES_CUBE.
2.
In the Maintenance Wizard, click Finish
to begin the load process.
Note: The default settings for an immediate build of all cube objects
is applied.
Result: The following information box appears:
3.
When the build completes, the Build Log window appears.
If you scroll to the right, and then down in the Build Log, you can
see how each of the cube partitions were processed. Click Close
after you finish examining the Build Log.
Note: There are several logs that you can view from the navigator by
clicking on the Reports node.
5.
You can view OLAP data from within AWM.
In the Navigator, right-click on the SALES measure
and select View Data Sales from the menu.
Result: Sales data is displayed for a default set of dimension members
in a crosstab and a graph.
6.
In the Data Viewer, drill on All Years.
The following data appears in the crosstab:
Note: CY2008 is blank because data for the 2008 calendar year is not
stored in the relational schema. CY2008 time periods are built into
the OLAP data model so that new data can be automatically updated with
subequent data loads.
7.
Click the Query Builder tool , under the File menu.
8.
In the Items tab, perform the following:
a) Select Sales Pr Year and Sales Pr Year
Pct Chg.
b) Click the Add Selected Items tool (>) to move
those two measures to the Selected list, like this:
9.
Click the Layout tab. In the Layout
tab, drag the appropriate dimension tiles to the correct axis so that
the layout looks like this:
10.
Click the Dimensions tab. In the Dimensions
tab, perform the following:
a) Select the Time dimension from the Choose drop-down
list.
b) Click the Remove All Items tool (<<) to clear
the Selected list.
c) In the Members tab of the Available list, drill on All
Years > CY2007.
d) Select all four quarters in CY2007, like this:
e) Click the Add Items tool (>) to move the 2007
quarters to the Selected list, like this:
f) Select Product from the Choose drop-down list.
g) Click the Remove All Items tool and then drill
on All Products in the Available list. Finally, select
the three Product department members, like this:
h) Click the Add Items tool to move the department
members to the Selected list.
i) Click OK to view the data.
11.
Select any of the members from the Product dimension
header. The calculations are instantaneously updated.
Drill on any of the 2007 Quarter values to view the data at the month
level.
When you are done experimenting with the report, collapse all drills
on the Time dimension, so that only the four quarters of 2007 are displayed.
12.
Next, you modify the Data Viewer for a Year-to-Date analysis
report.
First, hide the Graph by clicking on the down arrow
of the Hide/Show tool.
13.
Then, click the Query Builder tool,
and in the Items tab, perform the following:
a) In the Selected list, select Sales Pr Year and
Sales Pr Year Pct Chg.
b) Click the Remove Selected Items tool (<).
c) In the Available list, select Sales Ytd, Sales
Ytd Pr Year Pct Chg , and How Is Sales Ytd.
d),Click the Add Selected Items tool (>).
Result: The Year to Date measures are added to the Selected list.
14.
In the Layout tab, swap the Product and Time dimensions,
so that Product is in the Row axis, and Time is in the Page Items axis,
like this:
15.
Click OK to view the data.
The calculated measures show:
The Sales Year-To-Date data (in this case, the same as Sales, since
Q1-CY2007 is selected).
The percent change when comparing Sales YTD for the current period
(Q1-2007) to Sales YTD for the prior year (Q1-2006).
Text values that describe Sales YTD percent change performance as
"Needs Improvement", "On Track", or "Outstanding".
Recall that a conditional CASE statement is used in this calculated
measure to produce the result.
16.
From the Time dimension header, select Q2-CY2007,
as shown here:
Result: The stored and calculated data updates with the correct values.
17.
From the Time dimension header, select Q4-CY2007.
The How Is Sales Ytd measure correctly reflects the newly queried
data.
18.
Drill on Computers.
Again, the YTD performance measures automatically update to reflect
the current selections.
19.
Finally, you modify the Data Viewer for a product ranking
and share report.
- First, collapse the Product dimension drills to display only the
three product departments.
- Second, select Q1-CY2007 from the Time dimension
header.
Then, click the Query Builder tool.
20.
In the Items tab, perform the following:
a) In the Selected list, selectSales Ytd,
Sales Ytd Pr Year Pct Chg , and How Is Sales
Ytd.
b) Click the Remove Selected Items tool (<).
c) In the Available list, select Sales Rank In Prod Prnt
and Sales Share Prnt Prod.
d),Click the Add Selected Items tool (>).
Result: The rank and share measures are added to the Selected list.
21.
Click OK to view the data.
The calculated measures show:
The rank of each Product dimension member within its hierarchy
parent.
The share of each product member as a percentage of sales returned
by that product member to its parent in the hierarchy.
22.
Drill on Computers.
The rank and share measures show the relative ranking and share contribution
for each of the Product division members in the Computer department.
23.
Select any Time member from the Page Items axis, and
the calculations update instantaneously.
Feel free to modify the report by drilling or selected other dimension
members.
When you are done, close the Measure Data Viewer.
24.
You can also perform ad-hoc, multidimensional analysis
against OLAP data with any SQL-based tool. Oracle OLAP data is made
directly accessible to SQL by a set of relational views that are automatically
created and maintained by Oracle OLAP. You query OLAP data by executing
simple SQL statements against these associated Cube Views.
Click SALES_CUBE_VIEW -- the view created for SALES_CUBE
-- to display information and data for the view.
Oracle OLAP creates and maintains views for each cube and dimension.
These views represent an OLAP Cube as a star schema with the following
characteristics:
A cube view plays the role of a fact table.
Dimension views and hierarchy views play the role of dimension
tables (a dimension and a hierarchy view are created and maintained
for each dimension in the OLAP data model).
Although SQL access to OLAP cubes is covered in another tutorial, an
example of a SQL query against the cube that you just created is provided
next.
25.
In the example shown here, SQL Developer is used to write
a SQL query.
The SQL statement, explained by in-line notes, queries the same data
that is selected by AWM in step 21.
Note: SQL Developer is shipped free with Oracle Database.
26.
The query above is executed, and the resulting output
shows the same data that was returned in step 21.
For information how to query OLAP data using SQL, see the Querying
OLAP 11g Cubes OBE lesson.