Release 10.1A: OpenEdge Data Management:
Database Administration

Creating after-image areas

You create after-image areas using PROSTRCT and a structure description file. Use PROSTRCT CREATE to create after-image areas when you first define your database, and PROSTRCT ADD to add after-image areas to an existing database.

To create AI areas when defining your database:

Create the structure description file for the database. See Chapter 1, "Creating and Deleting Databases," for a complete description of how to create a structure description file.
Define the data extents.
Define any BI extents.
Define any fixed-length AI extents. You must define four tokens in the file description line. Table 7–1 describes each token and value you enter for fixed-length files.

Table 7–1: File tokens 

Token	Description
Storage area type	Specifies the file type. Type a to indicate that this extent is an AI extent.
Extent pathname	Specifies the extent file pathname. Enter a pathname that represents a standard operating system file. If you do not supply an extension, the database engine automatically appends a .an extension.
Extent type	Specifies whether the extent is a fixed-length or variable-length extent. Type f for a fixed-length extent. It must be lowercase.
Extent size	Specifies the length of the extent in 1,024-byte (1K) units. The minimum length for a fixed-length extent is 16K. The extent length must be a multiple of 16K for all operating systems. If you specify any other size, PROSTRCT displays a warning message and rounds the size up to the next multiple of 16K. The maximum length of an extent depends on the size of the file system and/or physical volume that contains the extent.

The following example shows a fixed-length after-image extent definition:

a db/mary/apdir/test.a1 f 2048

Define any variable-length after-image extents. Only specify the first two tokens: the extent type and pathname. Unlike data or BI extents, you can define more than one variable-length after-image extent for a database.
Create the empty database structure using the PROSTRCT utility. For more information about the structure description file and PROSTRCT, see Chapter 14, " Maintaining Database Structure."
Create the initial database contents using the PROCOPY or PROREST utility. For more information about the PROCOPY and PROREST utilities, see Chapter 23, " Other Database Administration Utilities."

To add AI areas to an existing database:

Create a structure definition file containing the descriptions of the files you are adding to your database. See Table 7–1 for the tokens used to describe the files.
Use PROSTRCT ADD to add the new files to your database. For more information about the structure description file and PROSTRCT, see Chapter 14, " Maintaining Database Structure."
Use PROSTRCT LIST to save your updated database definitions in a structure file.