What does DDS stand for IBM?
data description specifications
However, data description specifications (DDS) describe data attributes in file descriptions that are external to the application program that processes the data. DDS is a convenient alternative to describe data attributes on the IBM i operating system.
What is logical file in as400?
A logical file is a database file that describes how data records contained in one or more physical files are presented to a program. The logical file does not contain data records.
What is multi format logical file in as400?
A multiple-format logical file allows you to use records from two or more physical files by referring to only one logical file. Each record format of such a multiple-format logical file is always associated with one or more physical files. You can use the same physical file in more than one record format.
How do you convert DDL to DDS?
When converting from DDS to DDL, you should first check the programs with a keyed access on the physical file. Then, create a new logical file or (even better) a SQL index with the appropriate key fields and change your RPG programs to access the new index or logical file instead of the physical file.
What is the difference between logical and physical record?
A physical record often is unstructured and has a fixed size related to the kind of physical media that stores it, and possibly to the location of the record on the media. A logical record often is structured (has various program-specific fields) and might be stored in some number of full or partial physical records.
Can a physical file have multiple record formats?
Only one record format name is allowed for a physical file.
What is DDS in as400?
Data description specifications (DDS) describe data attributes in file descriptions that are external to the application program that processes the data.
What is DDS in SQL?
A DDS described physical file can include a key definition. SQL tables are always unkeyed. But unique keys can be converted into a primary key, and there is no way to include non-unique keys in a SQL table. When converting from DDS to DDL, you should first check the programs with a keyed access on the physical file.
What is DDS in iSeries?
This topic provides an overview of data description specifications (DDS) on iSeries™ servers. Data description specifications (DDS) describe data attributes in file descriptions that are external to the application program that processes the data.