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BC430
Unit Summary
Unit Summary
You should now be able to:
•
Explain how the Repository Information System and the Where-used list for
ABAP Dictionary objects function
•
Describe the mechanism for handling dependent objects in the ABAP
Dictionary
•
Differentiate between the active and inactive version of an ABAP Dictionary
object.
2006/Q2
© 2007 SAP AG. All rights reserved.
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Unit Summary
BC430
144
© 2007 SAP AG. All rights reserved.
2006/Q2
Unit 6
Changes to Tables
Unit Overview
In this chapter, you will learn how to make changes to the existing tables.
Unit Objectives
After completing this unit, you will be able to:
•
Make changes to tables
•
Estimate the effect of these changes on the database
•
Convert tables
•
Continue terminated conversions
•
Add customer fields to SAP standard tables by means of append structures
without modifications
Unit Contents
Lesson: Changes to Tables....................................................146
Exercise 9: Changes to Database Tables ...............................161
Exercise 10: Database Utility (SE14) Dealing with Problems
(Optional) ....................................................................167
2006/Q2
© 2007 SAP AG. All rights reserved.
145
Unit 6: Changes to Tables
BC430
Lesson: Changes to Tables
Lesson Overview
Lesson Objectives
After completing this lesson, you will be able to:
•
Make changes to tables
•
Estimate the effect of these changes on the database
•
Convert tables
•
Continue terminated conversions
•
Add customer fields to SAP standard tables by means of append structures
without modifications
Business Example
The data structures of an application must be adjusted to changed processes,
exactly like the programs. For this purpose, you should now change existing
database tables for your project.
Database Changes to Transparent Tables
Figure 58: Changes to Tables
146
© 2007 SAP AG. All rights reserved.
2006/Q2
BC430
Lesson: Changes to Tables
Correct access by ABAP programs to a database table is only possible if the
runtime object of the table is consistent with the structure of the table in the
database. Each time the table is changed in the ABAP Dictionary, you must check
if the database structure of the table must be adjusted to the changed ABAP
Dictionary definition of the table when it is activated (when the runtime object
is rewritten).
The database structure does not have to be changed for certain changes to the
ABAP Dictionary. For example, you do not have to change the database structure
when the order of the fields in the ABAP Dictionary is changed (other than for
key fields). In this case the changed structure is simply activated in the ABAP
Dictionary and the database structure remains unchanged.
Figure 59: How is the Structure Adjusted?
The database table can be adjusted to the changed definition in the ABAP
Dictionary in three different ways:
•
By deleting the database table and creating it again. The table on the database
is deleted, the inactive table is activated in the ABAP Dictionary, and the
table is created again on the database. Data existing in the table is lost.
•
By changing the database catalog (ALTER TABLE). The definition of the
table on the database is simply changed. Existing data is retained. However,
indexes on the table might have to be built again.
•
By converting the table. This is the most time-consuming way to adjust
a structure.
2006/Q2
© 2007 SAP AG. All rights reserved.
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