Information

  • Database connections are managed in a connection pool by default.
    • Upon requirement, a connection from the connection pool will be 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 will only be closed when the client is closed.
  • Thus, there is always one connection per client. Further connections will be 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 will be kept open.
    • Resources will be used.