1. What represents the commercially oriented
model of the real world?
SAP’s Enterprise Data Model (EDM)
represents the commercially oriented model of the real world, while the ABAP
Dictionary contains the data processing-oriented model. The EDM is the top-level overview of the
entire system. At this level the exact
characteristics of the relationships between entities are not important, merely
knowing that the relationships exist is what matters.
2. What is an entity? How are entities represented in the ABAP
Dictionary?
An entity is an object that is of
interest and is uniquely identifiable.
It is an object about which information must be stored. Within the ABAP Dictionary, entities are
stored as records in a table.
3. What is an entity type? How are entity-types represented in the ABAP
Dictionary?
Entity types describe a set of
entities with common attributes. Each
entity type has a unique name and unique description. For example, the set of all customers would
be an entity type, while each individual customer would be an entity in that
type. Within the ABAP Dictionary, entity
types are stored as tables.
4. What is an attribute? How are attributes represented in the ABAP Dictionary?
Attributes describe an entity’s (or
entity type’s) features or characteristics.
Within the ABAP Dictionary, attributes are represented as fields in a
table.
5. How are business-rules represented in a data
model?
Business rules are represented in a
data model by relationships between entity types. The cardinality and category of those
relationships help define those rules.
Within the ABAP Dictionary, these relationships are implemented as
foreign key relationships.
6.
Name and describe the 5
entity relationship categories.
A.
Hierarchical: an entity type is dependent on the existence
of exactly one other entity type. In this case the primary key of the
referenced entity type is inherited by the
Dependent entity type.
B. Aggregating/Associative: an entity type is dependent on the existence
of multiple other entity types. This
type is used to resolve many-to-many relationships. The full primary keys of the referenced
entity types are inherited by the dependent entity type.
C.
Referential: an entity type refers to another entity type
but is not identified by the relationship.
It is possible to change or eliminate the relationship, but as long as
the relationship exists, it is non-optional.
The primary key of the referenced entity type is passed onto the
dependent entity type as a non-key field.
D.
Conditional-Referential: the same as a referential relationship,
but the relationship is optional.
E. Specialization: an entity type that
represents a subset of the referenced entity type but also has additional
attributes. In this case the referenced
entity type is called the generalization, and the dependent entity type is
called the specialization.
Generalizations and specializations have the same primary key fields but
are used to store different information in non-key fields.
7. How is the SAP Enterprise
Via the SAP Data Modeler.
8. What within R/3 manages data definitions?
The ABAP Dictionary manages data
definitions so that all data is described centrally and without redundancy,
thereby maintaining data integrity (all changes take immediate effect in all
relevant modules and need only be entered in one location).
9. What is the DB Utility? What is its transaction code?
The database utility is the interface
between the data dictionary and the relational database that underlies the SAP
system. It is used to create underlying
tables in the database that will be used in SAP. The DB utility supports tables, table
indexes, views, search helps, pools/clusters.
Certain overview functions are provided: background logs, background
jobs, restart logs. The processing
options offered are online, background and generate program (where the program
that is to execute the selected function is generated without actually executing
the function). The basic functions of
the DB utility are created, delete and convert, and delete, create again. There is a lock mechanism associated with the
DB utility in order to ensure that an existing operation may be completed
before another is triggered.
The transaction code for the DB
utility is SE14.
10. Explain the concept of tables, domains and
data elements.
A domain is used to group together
fields of similar technical characteristics.
Attributes such as format (data type), length, and output
characteristics are specified by the domain.
A data element must be associated with a domain, and it gives a
meaningful description to a field in a particular context. Tables consist of records (rows) and fields
(columns). Each field in a table must be
assigned to a data element (which is in turn assigned to a domain).
11. At the domain level, what within R/3 prevents
the user from entering invalid data?
1. Value table
2. Explicit values
12. Within the ABAP Dictionary, what ensures data
integrity between tables?
Foreign key relationships.
13. Which attributes of the answer to #12 help
further define relationships between tables? Name
and describe the two components of those attributes.
The semantic attributes of
foreign key relationships help further define business rules and enforce data
integrity. Those two attributes are cardinality
(how many of one item relate to how many of another) and foreign key field
type (similar to relationship categories in the Data Modeler).
14. What is the purpose of the ABAP Repository
Information System?
The ABAP Repository Information System allows
the retrieval of information about development
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