07_01_tabw90 2.0b unit 7 data load performance

7/31/2019 07_01_TABW90 2.0B Unit 7 Data Load Performance

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Data load performance considerations.

Data Load Performance

Contents:


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Describe the BW performance issues relatingto data loads.

List the data load recommendations forachieving better performance.

At the conclusion of this unit, you will be able to:

Data Load Performance: Unit Objectives


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Step 1 Get the number range of all involved objects.

Buffer Number Range Objects

If a large quantity of transaction data should be uploaded into

the BW, the number range buffer should be increased for the

dimensions with a high expected number of rows.


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Change the Buffering of the Number Range Objects


Step 2


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Delete Secondary Indexes Before Loading Data

Existence of secondary indexes on fact tables slows dataload performance drastically.

It requires that inserts are made into indexes as well as fact

table - much more work involved.

Dropping secondary indexes prior to data load means thatinserts are made to fact table only.

Indexes can be quickly rebuilt after data load is finished.

Issue


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Using InfoCube Data Load Performance Tools

Create Indexbutton:set automatic index

drop / rebuild

Statistics Structurebutton:possibility to recalculate DB

statistics after a data load


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Possible Settings for Indices and DB Statistics


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The master data load creates the SIDs to the key-values and the navigational attribute values.

This avoids your transaction data from containingmany characteristic attributes for which a new SIDmust be determined.

The insert on the characteristic table for loading thetransaction data is no longer necessary.

Issue

Load Master Data before Transaction Data


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Load Parallel

When loading large quantities of data it is recommendedthat you split the data into several files and take advantageof multiple processors to improve performance.

These files can then be loaded in parallel into the BW withseveral requests.

Prerequisites

Multiple processors

Quick Raid

Issue


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The size of an IDOC determines the granularity for

the database COMMITS and as a result can havean effect on performance.

Issue

Set Package Size


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Additional Data Load Tips

Use a predefined record length (ASCII file) when loadingfrom a file.

If possible load the data from a file from the applicationserver and not from the client workstation.


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Additional Data Load Tips

Create InfoCube in proper tablespaces(see note 156784).

Run loads at off hours.

Avoid large loads across a network.

Avoid reading load files from tape.

(copy to disk first)

Avoid placing input load files on the same disk drives orcontrollers as the tables being loaded.


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Describe the BW performance issues relatingto data loads.

List the data load recommendations forachieving better performance.

Now you are able to:

Data Load Performance: Unit Summary

07_01_tabw90 2.0b unit 7 data load performance

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