Progress
Database Administration
Guide and Reference
Relative- and Absolute-path Databases
Progress Version 9 databases can be either relative- or absolute-path. Relative-path databases are only used for special situations, such as installing the master database associated with a new application. Absolute-path databases are used in production environments. The following sections detail relative- and absolute-path databases.
Relative-path Databases
Relative-path databases are the simplest form of Version 9 databases. They contain most of the properties associated with pre-Version 9 (single volume) databases, in that they are made up of a minimum number of files and can be copied with OS commands. A relative-path database stores all extents associated with the database in the same directory as the control area. The control area contains relative paths to all the extents. You would use a relative-path database in the following situations:
Use the PRODB utility to create a relative-path database from an empty database. Figure 1–7 shows the result of using the PRODB utility. The dot at the start of each extent name indicates a relative path.
Figure 1–7: Relative-path Database Creation
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Schema must be loaded into an empty relative-path database to make it useful. Any standard technique for loading schema, such as a dump and load or by using PROCOPY, can be used. The database maintains its relative-path as long as its structure is not changed. As soon as areas or extents are added, the database becomes an absolute-path database.
Absolute-path Databases
An absolute-path database is used in most production situations. With an absolute-path database, extents associated with the database can be stored anywhere on the system. The control area contains absolute paths to each extent. Absolute-path databases should not be copied using OS tools; rather, PROBKUP and PROCOPY should be used so that all underlying files are properly backed up or copied.
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