LISTEN>/
- linkend="SQL-NOTIFY">NOTIFY> feature.
- Pending events are now stored in a memory-based queue rather than
- a table. Also, a payload> string can be sent with each
- event, rather than transmitting just an event name as before.
+ Add /contrib/pg_upgrade>
+ to support in-place upgrades from 8.3 or 8.4 to 9.0.
- New implementation of
- VACUUM FULL>.
- This command now rewrites the entire table and indexes, rather than
- moving individual rows to compact space. It is substantially faster
- in most cases, and no longer results in index bloat.
+ Multiple performance enhancements for specific types of queries,
+ including join elimination, which optimizes automatically generated
+ queries, such as those produced by object-relational mappers (ORMs).
- New contrib module
- pg_upgrade>
- to support in-place upgrades from 8.3 or 8.4 to 9.0.
+ Exclusion constraints
+ let database designers define uniqueness based on complex
+ criteria, including for non-scalar data such as time periods,
+ ranges and arrays.
- Multiple performance enhancements for specific types of queries,
- including elimination of unnecessary joins. This helps optimize some
- automatically-generated queries, such as those produced by
- object-relational mappers (ORMs).
+ As part of our decade-long effort to eliminate the pain of VACUUM,
+ VACUUM FULL>
+ is now substantially faster by rewriting the entire table and
+ indexes, rather than moving around single rows to compact space.
- SQL-EXPLAIN ">EXPLAIN> enhancements.
- The output is now available in JSON, XML, or YAML format, and includes
+ using-explain">EXPLAIN
+ plans are now available in JSON, XML and YAML format, and include
buffer utilization and other data not previously available.
- hstore> improvements,
- including new functions and greater data capacity.
+ The HStore optional module has been improved with new functions and greater
+ data capacity to make it a high-performance key-value store.
- Allow aggregate functions to use ORDER BY> (Andrew
+ Allow aggregate functions to use
+ linkend="syntax-aggregates">ORDER BY>> (Andrew
Gierth)