Progress
Database Administration
Guide and Reference
Connection Modes
Progress databases run in one of two connection modes: single-user or multi-user. Connection modes control how many users can access a database simultaneously.
Single-user Mode
A database running in single-user mode allows one user to access a specified database at a time. If another user is already accessing a database, you cannot connect to that database from a different Progress session. The database engine uses a lock file (.lk) to lock out other users.
Running a database in single-user mode is helpful when you perform system administration tasks that require exclusive access to the database.
Multi-user Mode
A database running in multi-user mode enables more than one user to access it simultaneously. A broker coordinates all the database requests from all the users using a single database. For example, the broker process locks the database to prevent any other broker or single-user process from opening it. Also, all users must request access from the broker to connect to the database.
Both single-user and multi-user processes can run in either interactive or batch mode. Table 1–2 compares these modes.
Copyright © 2004 Progress Software Corporation www.progress.com Voice: (781) 280-4000 Fax: (781) 280-4095 |