Persistent Database Connections New from S 39.5.16

Information

• Database connections are administered in a connection pool by default.
  • Upon requirement, a connection from the connection pool is assigned to a client. After the connection has been used (e.g. processing of an SQL query), it is retained and returned to the pool.
• If a persistent database connection is to be used instead (duration of the database connection = duration of the user session), connection pooling will be deactivated.
• Persistent database connections are connections which are not closed after an event has been processed.
• The connection is only closed if the client is closed.
• Thus, there is always a connection per client. Further connections are opened upon requirement.

Details

• Whether a single persistent database connection is used per client session is controlled via the persistent_db_session parameter.
• The parameter affects the entire PLANTA project instance and therefore applies system-wide.
• The parameter is deactivated by default.
• In order to activate it, the persistent_db_session parameter under config/globals.conf must be set to true.

Advantages

• During a user session, user-specific data can, e.g., be stored in temporary tables.

Disadvantages

• Database connection limits must be adjusted to the maximum number of sessions.
  • Number of users
  • Connections for the extraction of auto-IDs (connection is established shortly and closed again)
  • One connection for the server session
• Connection is kept open.
  • Resources are used.