Using OLAP functions without a DMR model

This is on Cognos 10.1.1 with the GO Data Warehouse (query) package.

I was asked a somewhat difficult question. On a relational model the report shows a crosstab years with another attribute nested in rows and measures in columns. How can the growth % of the years from the previous year to the current year be displayed?

Normally I would create data items for each measure for each year that needs to be included in the expression. Something along the lines of
case when [Year] = extract(‘year’,current_date) then [Measure] else 0 end
The issue with this is that this is a crosstab – how can you make it accommodate different measures on different edges?

A better solution would be one that mimics dimensional functionality. I want to divide 2011 by 2010, with all of the measures acting accordingly.

In a dimensional query I would simply do [Current Year]/[Previous Year]. If I didn’t have any calculated members in the cube, I might try something like this:

item(filter([Year Level],[Year Caption] = #sq(timestampMask(‘yyyy’,$current_timestamp))#),0)

The filter returns a set of all of the years that match the current year, and the item takes that set and returns the first member in it.

Because this is a relational model, OLAP functions shouldn’t work.

(item(filter([Year],[Year]=2007),0)/item(filter([Year],[Year]=2006),0))-1

But they do.

My guess is that Cognos is implicitly converting the [Year] field into a level, like it would be in a DMR model. The odd thing is, that while it works, I don’t see it reflected in the SQL of the xtab.

Cognos SQL:

select
       SLS_ORDER_METHOD_DIM.ORDER_METHOD_EN  as  Order_method_typekey,
       GO_TIME_DIM.CURRENT_YEAR  as  Yearkey,
       XSUM(SLS_SALES_FACT.QUANTITY  for SLS_ORDER_METHOD_DIM.ORDER_METHOD_EN,GO_TIME_DIM.CURRENT_YEAR )  as  Quantity,
       XSUM(SLS_SALES_FACT.SALE_TOTAL  for SLS_ORDER_METHOD_DIM.ORDER_METHOD_EN,GO_TIME_DIM.CURRENT_YEAR )  as  Revenue,
       XSUM(SLS_SALES_FACT.GROSS_PROFIT  for SLS_ORDER_METHOD_DIM.ORDER_METHOD_EN,GO_TIME_DIM.CURRENT_YEAR )  as  Gross_profit
 from
       great_outdoors_warehouse..GOSALESDW.SLS_ORDER_METHOD_DIM SLS_ORDER_METHOD_DIM,
       great_outdoors_warehouse..GOSALESDW.GO_TIME_DIM GO_TIME_DIM,
       great_outdoors_warehouse..GOSALESDW.SLS_SALES_FACT SLS_SALES_FACT
 where
       (GO_TIME_DIM.CURRENT_YEAR in (2006,2007)) and
       (SLS_SALES_FACT.ORDER_METHOD_KEY = SLS_ORDER_METHOD_DIM.ORDER_METHOD_KEY) and
       (SLS_SALES_FACT.ORDER_DAY_KEY = GO_TIME_DIM.DAY_KEY)
 group by
       SLS_ORDER_METHOD_DIM.ORDER_METHOD_EN,
       GO_TIME_DIM.CURRENT_YEAR

Running a trace in SQL Server shows that it’s not doing anything different:

declare @p1 int
set @p1=1
exec sp_prepare @p1 output,NULL,N'select "SLS_ORDER_METHOD_DIM"."ORDER_METHOD_EN" AS "Order_method_typekey", "GO_TIME_DIM"."CURRENT_YEAR" AS "Yearkey", sum("SLS_SALES_FACT"."QUANTITY") AS "Quantity", sum("SLS_SALES_FACT"."SALE_TOTAL") AS "Revenue", sum("SLS_SALES_FACT"."GROSS_PROFIT") AS "Gross_profit" from "GOSALESDW"."SLS_ORDER_METHOD_DIM" "SLS_ORDER_METHOD_DIM", "GOSALESDW"."GO_TIME_DIM" "GO_TIME_DIM", "GOSALESDW"."SLS_SALES_FACT" "SLS_SALES_FACT" where "GO_TIME_DIM"."CURRENT_YEAR" in (2006, 2007) and "SLS_SALES_FACT"."ORDER_METHOD_KEY" = "SLS_ORDER_METHOD_DIM"."ORDER_METHOD_KEY" and "SLS_SALES_FACT"."ORDER_DAY_KEY" = "GO_TIME_DIM"."DAY_KEY" group by "SLS_ORDER_METHOD_DIM"."ORDER_METHOD_EN", "GO_TIME_DIM"."CURRENT_YEAR"',1
select @p1

So it must be doing the calculation locally. Local processing is frowned upon, so you should try to find another way to handle this. Ideally building a real cube and using real OLAP functionality.

Report XML:

<report xmlns="http://developer.cognos.com/schemas/report/8.0/" useStyleVersion="10" expressionLocale="en-us">
				<modelPath>/content/folder[@name='Samples']/folder[@name='Models']/package[@name='GO Data Warehouse (query)']/model[@name='model']</modelPath>
				<drillBehavior modelBasedDrillThru="true"/>
				<layouts>
					<layout>
						<reportPages>
							<page name="Page1">
								<style>
									<defaultStyles>
										<defaultStyle refStyle="pg"/>
									</defaultStyles>
								</style>
								<pageBody>
									<style>
										<defaultStyles>
											<defaultStyle refStyle="pb"/>
										</defaultStyles>
									</style>
									<contents><crosstab horizontalPagination="true" name="Crosstab1" refQuery="Query1" rowsPerPage="999999">
			<crosstabCorner>
				<contents/>
				<style>
					<defaultStyles>
						<defaultStyle refStyle="xm"/>
					</defaultStyles>
				</style>
			</crosstabCorner>

			<noDataHandler>
				<contents>
					<block>
						<contents>
							<textItem>
								<dataSource>
									<staticValue>No Data Available</staticValue>
								</dataSource>
								<style>
									<CSS value="padding:10px 18px;"/>
								</style>
							</textItem>
						</contents>
					</block>
				</contents>
			</noDataHandler>
			<style>
				<CSS value="border-collapse:collapse"/>
				<defaultStyles>
					<defaultStyle refStyle="xt"/>
				</defaultStyles>
			</style>
		<crosstabRows><crosstabNode><crosstabNestedNodes><crosstabNode><crosstabNodeMembers><crosstabNodeMember refDataItem="Order method type" edgeLocation="e7"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode></crosstabNestedNodes><crosstabNodeMembers><crosstabNodeMember refDataItem="2007 %" edgeLocation="e6"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><dataItemValue refDataItem="2007 %"/></dataSource></textItem></contents><factCell><style><defaultStyles><defaultStyle refStyle="mv"/></defaultStyles><dataFormat><percentFormat/></dataFormat></style></factCell></crosstabNodeMember></crosstabNodeMembers></crosstabNode><crosstabNode><crosstabNestedNodes><crosstabNode><crosstabNodeMembers><crosstabNodeMember refDataItem="Order method type" edgeLocation="e2"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode></crosstabNestedNodes><crosstabNodeMembers><crosstabNodeMember refDataItem="Year" edgeLocation="e1"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode></crosstabRows><crosstabFactCell><contents><textItem><dataSource><cellValue/></dataSource></textItem></contents><style><defaultStyles><defaultStyle refStyle="mv"/></defaultStyles></style></crosstabFactCell><crosstabColumns><crosstabNode><crosstabNodeMembers><crosstabNodeMember refDataItem="Quantity" edgeLocation="e3"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode><crosstabNode><crosstabNodeMembers><crosstabNodeMember refDataItem="Revenue" edgeLocation="e4"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode><crosstabNode><crosstabNodeMembers><crosstabNodeMember refDataItem="Gross profit" edgeLocation="e5"><style><defaultStyles><defaultStyle refStyle="ml"/></defaultStyles></style><contents><textItem><dataSource><memberCaption/></dataSource></textItem></contents></crosstabNodeMember></crosstabNodeMembers></crosstabNode></crosstabColumns></crosstab></contents>
								</pageBody>
							</page>
						</reportPages>
					</layout>
				</layouts>
			<XMLAttributes><XMLAttribute name="RS_CreateExtendedDataItems" value="false" output="no"/><XMLAttribute name="listSeparator" value="," output="no"/><XMLAttribute name="RS_modelModificationTime" value="2011-06-09T13:50:33.233Z" output="no"/></XMLAttributes><queries><query name="Query1"><source><model/></source><selection><dataItem name="Year" aggregate="none" rollupAggregate="none"><expression>[Sales (query)].[Time].[Year]</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="1" output="no"/><XMLAttribute name="RS_dataUsage" value="attribute" output="no"/></XMLAttributes></dataItem><dataItem name="Order method type" aggregate="none" rollupAggregate="none"><expression>[Sales (query)].[Order method].[Order method type]</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="3" output="no"/><XMLAttribute name="RS_dataUsage" value="attribute" output="no"/></XMLAttributes></dataItem><dataItem name="Quantity" aggregate="total"><expression>[Sales (query)].[Sales fact].[Quantity]</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="1" output="no"/><XMLAttribute name="RS_dataUsage" value="fact" output="no"/></XMLAttributes></dataItem><dataItem name="Revenue" aggregate="total"><expression>[Sales (query)].[Sales fact].[Revenue]</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="2" output="no"/><XMLAttribute name="RS_dataUsage" value="fact" output="no"/></XMLAttributes></dataItem><dataItem name="Gross profit" aggregate="total"><expression>[Sales (query)].[Sales fact].[Gross profit]</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="2" output="no"/><XMLAttribute name="RS_dataUsage" value="fact" output="no"/></XMLAttributes></dataItem><dataItem name="2007 %"><expression>(item(filter([Year],[Year]=2007),0)/item(filter([Year],[Year]=2006),0))-1</expression><XMLAttributes><XMLAttribute name="RS_dataType" value="1" output="no"/><XMLAttribute name="RS_relationalExpression" value="true" output="no"/></XMLAttributes></dataItem></selection><detailFilters><detailFilter><filterExpression>[Year] in (2006,2007,2008)</filterExpression></detailFilter></detailFilters></query></queries><reportName>test</reportName></report>