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59 Cards in this Set
- Front
- Back
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9 Performance Tuning
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9 Performance Tuning
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9.1 Intro to QPO
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9.1 Intro to QPO
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what must be considered prior to installation of BI system?
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1) resource sizing 2) performance goals
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who is the frst contact for poor performance?
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power user - query authors and functional representatives
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what is Query monitor? How do you access it?
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tool to determine root cause of performance problems 2) RSRT
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9.2 BI Aggregates
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9.2 BI Aggregates
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what is an Aggregate?
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summarized view of data in InfoCube
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how is data stored in aggregate?
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redundantly and persistently in its own Info cube like structure on database
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what is the similarity and difference between Infocube aggregate and database index?
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"a) similarity – both improve system performance b) difference– technically different"
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how does users know aggregate is built?
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queries will run faster
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for what types of objects, can aggregates be created?
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"a) Infocubes b) not virtualcubes; DSO"
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How are aggregates formed on Infocubes?
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"by selecting specific objects connected to Infocubes a) characteristics in dimension tables b) hierarchies associated with Info cubes c) Navigational attributes associated with Info cubes"
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how does using aggregates reduce the volume of data accessed for each query?
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"because data is stored in separate Infocube this contains limited set of chars from the connected Infocube"
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what is the role of OLAP processor in navigation of query?
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"a) OLAP processor picks the most efficient aggregate if the navigation of the query is supported by the aggregate b) user does not target the aggregate"
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where are aggregates particularly useful?
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"a) improves the speed of group of queries b) speed up execution and navigation of a highly used specific query c) improves run time of queries with navigational attributes d) to speed up reporting on characteristic hierarchies by aggregatingspecific hierarchy levels:"
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where from in Infocube can attributes be built from?
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"InfoCubes a) characteristics b) navigational attributes c) hierarchies"
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what type of navigational attributes and hierarchies can be used in aggregates?
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"a) time dependent b) time independent"
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what type of objects complicates the ability to utilize the aggregate by query?
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time dependent objects
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how are aggregates defined?
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"a) '*' inclusive b) ' ' exclusive c) 'F' inclusive with a fixed value d) 'H' hierarchy level;"
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a) '*' inclusive;
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the characteristic is used in the summarization
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b) ' ' exclusive;
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a characteristic is not used in the summarization
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c) 'F' inclusive with a fixed value;
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the characteristic is summarized with a specific fixed value
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'H' hierarchy level;
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the characteristic is summarized for a specific hierarchy level
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how do you define the granularity of the data and what reporting requirementsthe aggregate will fulfill?
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by adding characteristics, hierarchies, and navigational attributes to youraggregate,
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what does exception aggregation mean?
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Exception aggregation means that the key figure behaves differentlywhen analyzed against different characteristics.
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1) what are the different types of properties that aggregates have?
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a) technical b) status c) content |
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2) where are they stored?
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2) stored in table RSDDAGGRDIR
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3) where are they displayed
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3) displayed on GUI
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what are the options when you are prevented from using an aggregate?
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a) Switch off aggregate b) Deactivate the aggregate c) delete the aggregate"
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what does each aggregate consist of?
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"a) two fact tables E and F b) at least two dimension tables – package and customer defined c) unit dimension is not mandatory"
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what are time dependent aggregates?
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aggregates using time dependent master data
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what is filling of aggregate?
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initial loading of data into aggregate
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what is a rollup?
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loading of new data from Infocube into Infocube's aggregates
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how does rollup take place?
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a) when Infocube request is loaded into aggregates b) rollup consists of one or more requests c) request id controls the request d) request ID is stored in the package dimension of Infocube
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how can you optimize aggregates?
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a) system automatically proposed new aggregates b) by analyzing slow queries c) using BI statistics data of query run times
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when do you need to change the structure of attributes?
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when changes are made to attributes or hierarchies from characteristics used in aggregates
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why do you need to be careful when creating navigation attribute?
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a) costly to maintain b) change in attribute value causes adjustment or rebuilt of all aggregates
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what does time needed for change run depends on?
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"a) number of navigational attributes and hierarchies b) how frequently master data is changed for for each char infoobjects"
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what versions of attributes and hierarchies are used during change run?
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old versions of attributes and hieracrhies
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what is the monitoring function used to check which objects are affected by change runs?
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RSA1–>Administration–>Change run
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when is a change run usually executed?
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after master data is loaded via a process chain
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what happens when aggregated are automatically compressed during rollup?
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"a) requests written to E fact table of aggregate IC b) removes request Id – compression can be applied across all requests. c) data records with same char value are aggregated"
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what are two main uses of process chains for aggregates?
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"a) to execute attribute change run b) rollup c) not used to initial filling of attributes"
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9.3 BI Accelerator
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9.3 BI Accelerator
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what is BIA
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a “snap-in” hardware and software “appliance” that will solve many performance issues.
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how does BIA proces the information in InfoCubes
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indexes the info in InfoCubes to create compressed structure that can be loaded into memory as needed.
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advantages of BIA
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a) fast query response b) user satisfaction c) stable query response d) scalability e) reduced TCO f) low maintenance.
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why is BIA highly reusable
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very few can be used to accelerate many different queries.
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reason for not adopting BIA?
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cost.
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what is the unique advantage of BIA?
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provides highest reusability with fast performance
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9.4 Statistics Overview
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9.4 Statistics Overview
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one metric you will use to measure the success of your BI project?
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Performance
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what is BI Statistics?
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tool for analysis and optimization of BI system.
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what does BI Statistics enable? How?
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a) to get overview of BI Load and analysis processes-queries etc b) throught standard objects and tools
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what does BI Admin cockpit do?
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primary job is to organize and display BI statistics data b) can be configured to obtain data from SAP CCMS
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what are used to source data in support of BI Admin cockpit?
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Infocubes- Virtual providers-Multiproviders
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how do you monitor performance?
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a) by designing custom queries, web templates and portal views b) utilize delivered portal and BI content
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what is BI statistics-BI content?
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a) SAP NW BI Admin role b) IC c) VP d) MP e) Process chains f) ETL g) sources h) info objects i) web pages j) portal package
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Why are change runs needed?
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Change runs repair aggregates that are built on changing master data.
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