PostgreSQL 9.2.4 / 9.1 rc 1

This release has been largely focused on performance improvements, though new SQL features are not lacking. Work also continues in the area of replication support. Major enhancements include:•Allow queries to retrieve data only from indexes, avoiding heap access •Allow the planner to generate custom plans for specific parameter values even when using prepared statements•Improve the planner's ability to use nested loops with inner index scans•Allow streaming replication slaves to forward data to other slaves •Allow pg_basebackup to make base backups from standby servers•Add a pg_receivexlog tool to archive WAL file changes as they are written•Add the SP-GiST (Space-Partitioned GiST) index access method•Add support for range data types•Add a JSON data type•Add a security_barrier option for views•Allow libpq connection strings to have the format of a URI•Add a single-row processing mode to libpq for better handling of large result setsThe above items are explained in more detail in the sections below.