Managing database members

 

You can perform various operations on database file members, such as adding and removing members and changing member attributes.

Before you perform any input or output operations on a file, the file must have at least one member. As a general rule, a database file has only one member, the one created when the file is created. The name of this member is the same as the file name, unless you give it a different name. Because most operations on a database file assume that the member being used is the first member in the file, and because most files only have one member, usually you do not have to be concerned with, or specify, member names.

If a file contains more than one member, each member serves as a subset of the data in the file. This allows you to classify data easier. For example, you define an accounts receivable file. You decide that you want to keep data for a year in that file, but you frequently want to process data just one month at a time. For example, you create a physical file with 12 members, one named for each month. Then, you process each month's data separately (by individual member). You can also process several or all members together.

• Member operations common to all database files
  The system allows you to make changes to file definitions. You can use control language (CL) commands to perform most of these operations.

• Physical file member operations
  Some member operations are unique to physical file members.

 

Parent topic:

Managing database files