Hello, We have a database containing PostGIS MAP data, it is accessed mainly via JDBC. There are multiple simultaneous read-only connections taken from the JBoss connection pooling, and there usually are no active writers. We use connection.setReadOnly(true). Now my question is what is best performance-wise, if it does make any difference at all: Having autocommit on or off? (I presume "off") Using commit or rollback? Committing / rolling back occasionally (e. G. when returning the connection to the pool) or not at all (until the pool closes the connection)? Thanks, Markus -- Markus Schaber | Logical Tracking&Tracing International AG Dipl. Inf. | Software Development GIS Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org