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Data Modelling in ASAM ODS

Presentation by Helmut J. Helpenstein, June 2005

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ASAM ODS supports a particular way of storing data

xx

yy

Technical data

Meta information

Application A

Application B

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Goals of ODS way• Combination of data and meta data• Meta data according to a Base Model

The Base Model• defines common attributes and relationships for all test

and measurement data• defines rules and methods how to derive customized

(application specific) data models from the ASAM ODS Base Model

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Base Model and Application Model

basemodel

derivation applicationmodel

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Application Model

It has several tasks:• support the application• express any wanted details in a recognizable way• enable clients to understand semantics

For each purpose the application model should use those constructs that are provided in the base model for that purpose.

Base model influences application model.Application model influences data.

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Application Model and Data

applicationmodel

instantiation data

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Constructs in the Base Model

• Hierarchical structurestests - measurements, equipments - devices, …

• Valuesapplication attributes, instance attributes, parameters

• Measurement datasubmatrices, local columns, value sequence

• References pointers to other elements• Groups

units, quantities, users

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Hierarchical Structures

Parent entity has a set of references in a „children“ attribute (main browse direction)

Child entity has single reference in a „parent“ attribute (inverse direction)

Test Test

Test 'Test '

INV parentSET children

Test "Test "

INV parentSET children

MeasurementMeasurement

INV testSET measurements

. . . . .

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Add a value to one or more instances

Application attribute: - is attached to ALL instances - easily recognizable by application - ideal for generic clientInstance attribute: - is attached to 1 instance - recognizable by application - acceptable for generic clientParameter: - has reference to 1 instance of specific type - requires special application model - not for use in generic clients

Entity A Attribute a

Instance A1InstAtt a1

Entity A

Parameter P

Instance A1

Instance P1

value

value

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Measurement data

Application attribute: - recognizable by special application - single values

Instance attribute or Parameter: - extremely special

Local columns: - ODS way => easily recognizable by applications and generic clients - sequences of values - concept of submatrices to handle all measurement cases - dedicated entities

Entity A Attribute a

Instance A1InstAtt a1

Entity A

Parameter P

Instance A1

Instance P1

value

value

AoMeasurement

AoMeasurementQuantity AoSubmatrix

AoLocalColumn

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Submatrices and value matrixSubmatrix smaTime MeaQ_A 0.1 xxx1 0.2 xxx2 0.3 xxx3 0.4 xxx4

Submatrix smbTime MeaQ_B 0.2 yyy1 0.24 yyy2 0.28 yyy3 0.32 yyy4 0.36 yyy5 0.4 yyy6

Value matrix Time MeaQ_A MeaQ_B 0.1 xxx1 0.2 xxx2 yyy1 0.24 yyy2 0.28 yyy3 0.3 xxx3 0.32 yyy4 0.36 yyy5 0.4 xxx4 yyy6

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Base model for measurement values

BASEELEM AoMeasurement - name - id - measurement_quantities - submatrices

BASEELEM AoMeasurementQuantity - name - id - local_columns

BAESELEM AoSubmatrix - name - id - number_of_rows - local_columns

BASEELEM AoLocalColumn - name - id - sequence_representation - generation_parameters - values - external_component

seq_rep values gen_pars ext_compexplicit ximplicit_linear xraw_linear x xexternal_comp xraw_lin_ext x x

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References / Relations In a model, each entity is determined by ist attributes.

In ASAM ODS application models, entities are called Application Elements, their attributes can contain values (numerical or text) or relations (references to other objects).

Example: In a directory there are some files.

APPLELEM directory - name (string) - id (integer) - files (set of file)

APPLELEM file - name (string) - id (integer) - home (directory)

c:\meyer\abc (177)

house.doc (29)

car.txt (56)

list.xls (115)

INSTELEM directory - "c:\meyer\abc" - 177 - 29,56,115INSTELEM file - "house.doc" - 29 - 177INSTELEM file - "car.txt" - 56 - 177INSTELEM file - "list.xls" - 115 - 177

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Groups• An item belongs to

one or more groups

• A group has one or more items

• This is a many-to-many relationship (n:m)

BASEELEM AoUnit name (string) id (integer) groups (SET of AoUnitGroup) phys_dim (AoPhysicalDimension) factor (double) offset (double)

BASEELEM AoUnitGroup name (string) id (integer) units (SET of AoUnit)

AoUnit AoUnitGroup

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Example of application model

TestBed (AoTest) | | Test (AoSubTest) | | | | | -----------------------------------+ | +--------------------+ | | | Engine (AoUnitUnderTest)Measurement (AoMeasurement) User (AoUser) | | test engineer | | User (AoUser)MeaQuantity (AoMeasurementQuantity) design engineer

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Filtered data

TestBed Location="Aachen" | | Test Type="class C" | || | |-----------------+ | +-----+ | | | | Measurement | | Begin > 200502 | | | | | | | | Engine Fuel="Diesel" | | | NumberOfCylinders=5MeaQuantity | | | | test engineer | Description="Test Engineer" | Division="Block D" | (Test.Type="class C") | | | Description="Design Engineer" design engineer Division="Block D"

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Select Measurements in DIAdem• Precondition: Modelling according to ODS way• Size of example data: 45 MB

many TestBeds, each with many Tests• Measurements can be imported with their

MeasurementQuantities• We want to find data in a limited set, described by

filtering with conditions - enabled by modelling in ODS way

• MeasurementQuantities can be displayed• Screenshots display the filtering process

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Thank you for your attention.