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ABAP Keyword Documentation → ABAP Programming Guidelines → Architecture → Data Storage →Persistent Data Storage
Background
ABAP programs can have both read and write access to data in the following persistent storage media:
According to the SoC principle, such accesses are wrapped in service classes of the persistency layer of an application.
Rule
Plan persistent data storage carefully
Select with care the persistent storage media that are used by the application as well as the possible data transport routes between these media. Here is a general rule of thumb:
Details
When you plan persistent data storage, you should follow these steps:
Under no circumstances should you use existing database tables (or files) to store data that are not provided for this purpose. Follow the convention of restricting reads and writes to database tables to specific packages. A database table must always be considered a semantic entity that is only allowed to contain the corresponding data. This even applies if a table with the required structure already exists. If in doubt, you should create a specific database table.
You must also be careful when using seemingly cross-system resources, such as the predefined INDX database table, to store data clusters. Such a resource must only be used to store temporary data for the short term, if at all. You should create specific database tables, for example, INDX-type tables, for application-specific and longer-lasting data.