From PostgreSQL wiki
Email Release Text
The PostgreSQL Global Development Group announces the release of PostgreSQL 9.1. This latest version of the leading open source database offers innovative technology, unmatched extensibility, and new features such as synchronous replication, K-Nearest Neighbor indexing, and foreign data wrappers.
“PostgreSQL 9.1 provides some of the most advanced enterprise capabilities of any open source database, and is backed by a vibrant and innovative community with proven customer success. PostgreSQL is well positioned for building and running applications in the cloud,” said Charles Fan, Sr. VP R&D, VMware.
Responding to Users
- Synchronous Replication: enable high-availability with consistency across multiple servers
- Per-Column Collations: support linguistically-correct sorting per database, table or column.
- Unlogged Tables: greatly improves performance for ephemeral data
"Heroku runs the largest PostgreSQL database-as-a-service in the world," said James Lindenbaum, Heroku co-founder. "The release of synchronous data replication with 9.1 provides our customers with innovative new ways of protecting mission-critical data, and validates PostgreSQL as one of the fastest-moving datastores available."
Advancing the State of the Art
Our community of contributors is innovating with cutting-edge features, including ones new to the entire database industry. Some of the new features that are only available on PostgreSQL:
- K-Nearest-Neighbor Indexing: index on "distance" for faster location and text-search queries
- Serializable Snapshot Isolation: keeps concurrent transactions consistent without blocking, using "true serializability"
- Writeable Common Table Expressions: execute complex multi-stage data updates in a single query
- Security-Enhanced Postgres: deploy military-grade security and Mandatory Access Control
"OpenERP has always relied on the enterprise-class features of PostgreSQL to provide a fast, reliable and scalable foundation for the Business Applications supporting our customers' operations every day. Data integrity in highly concurrent and transactional contexts is a critical topic for us, and we're very enthusiastic about the new Serializable Snapshot Isolation of PostgreSQL 9.1!" said Olivier Dony, OpenERP Community Manager.
Extending the Database Engine
PostgreSQL's extensibility enables users to add new functionality to a running production database, and use them for tasks no other database system can perform. Version 9.1 adds critical new extensibility features, including:
- Foreign Table Wrappers: attach and query other databases from PostgreSQL
- Extensions: easily create, load, and manage new database features
All of the above features, and more, are detailed on the What's New In 9.1 wiki page, as well as our release notes.
In PostgreSQL's 25th year of database development, our community continues to introduce new innovations with every annual release. Download version 9.1 now and experience the most advanced open source database system in the world.
Details of New Features
Responding to Users
- Synchronous Replication for Clustering: Enable high-availability with consistency across multiple nodes, by deploying PostgreSQL clusters using synchronous replication. Synchronous replication supports "2-safe replication" which ensures transactions have been confirmed by a standby server in addition to the master. Synchronous replication improves reliability over other techniques, and data loss will be limited to events where both the primary and standby servers crash at the same time.
- Per-column Collations for Multi-lingual Databases: Users can now set the collation for strings on a single column. This permits true multilingual databases, where each text column is a different language, and indexes and sorts correctly for that language.
- Unlogged Tables to Improve Performance: When performance is more important than durability, unlogged tables provide a way to improve performance while keeping the data managed within PostgreSQL. Removing logging reduces I/O overhead, yielding performance improvements up to 10 times faster when compared to logged tables. Scenarios expected to leverage unlogged tables include web session data, real time logging, ETL and temporary/intermediate tables for functions.
Advancing the State of the Art
- Powerful Similarity Searches with K-Nearest-Neighbor (KNN) Indexing: Create new applications using PostgreSQL KNN-GiST indexes, which provide innovative indexing to avoid expensive table scans. KNN enhances PostgreSQL's query capabilities by using mathematical "distance" for indexing and searches. These indexes can be used to enhance common text searches, text-similarity searches, geospatial location comparisons and other queries. Example searches that took 2 seconds without the index returned in 20 ms with this feature. Text search indexes can be also now be configured to provide indexing support for LIKE '%string%' queries without changing any SQL. PostgreSQL is among the first database systems to have KNN.
- Serializable Snapshot Isolation: allows users to enforce arbitrarily complex user-defined business rules within the database without blocking, by automatically detecting live race conditions in your SQL transactions at runtime. This feature currently exists only in PostgreSQL.
- Writeable Common Table Expressions (wCTE): Supports the relational integrity of your data by allowing you to update multiple, cascading, related records in a single statement. By using the results of one query to execute another query, you can update recursively, hierarchically, across foreign keys, or even more creatively. PostgreSQL provides the most complete and flexible implementation of this SQL feature available.
- Security-Enhanced Postgres (SE-Postgres): Deploy military-grade security and mandatory access control with full-integration support for Security-Enhanced Linux (SE-Linux). SE-Linux is a NSA project that modifies the Linux kernel with security-related functions. It has been endorsed by and included with major Linux distributions including, but not limited to, Red Hat, CentOS, Debian and Ubuntu. PostgreSQL is the only database system which has tight integration with SE-Linux.
Extending the Database Engine
- Foreign Data Wrappers (FDW): as part of our standards-compliant SQL/MED support for querying data outside the PostgreSQL database, FDWs allow users to create "drivers" and attach external data sources, which can be used as read-only tables. FDWs make PostgreSQL a powerful tool for enterprise data integration, and they make migration easier. FDWs initially available from the community include comma-separated-value (CSV) files, Oracle, MySQL, CouchDB, and Twitter sources. And many more are expected in the near future.
- Extensions: while PostgreSQL has always been extensible, now users can easily create, load, upgrade, and manage any of dozens of database extensions using the EXTENSION database object. The new site PGXN.org offers a repository for contributing and downloading extensions.
The POSTGRES project was inaugurated at the University of California, Berkeley, in June 1986 with the publication of the original POSTGRES desing by Lawrence A. Rowe and Michael R. Stonebraker. In the 25 years since then, POSTGRES became an open source project, converted to using SQL, changed its name to PostgreSQL, and became one of the leading relational databases in the world.
There have been 23 releases of POSTGRES and PostgreSQL, including version 9.1. PostgreSQL is the only major SQL database system to have consistent, featureful releases every year.
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About VMWare: VMware (NYSE:VMW), the global leader in virtualization and cloud infrastructure, delivers customer-proven solutions that accelerate IT by reducing complexity and enabling more flexible, agile service delivery. VMware enables enterprises to adopt a cloud model that addresses their unique business challenges. VMware’s approach accelerates the transition to cloud computing while preserving existing investments and improving security and control. With more than 250,000 customers and 25,000 partners, VMware solutions help organizations of all sizes lower costs, increase business agility and ensure freedom of choice. Contact: email@example.com or phone +1 (650) 427-2485
About Heroku: Heroku provides a platform as a service (PAAS) for building, deploying, and running cloud apps using Ruby. The architecture of our platform includes tools for deployment and management, a runtime for scalability, fault tolerance, and an add-ons system for extending the capabilities of our platform. Contact: Jill Ratkevic (firstname.lastname@example.org)
"OpenERP has always relied on the enterprise-class features of PostgreSQL to provide a fast, reliable and scalable foundation for the Business Applications supporting our customers' operations every day. Data integrity in highly concurrent and transactional contexts is a critical topic for us, and we're very enthusiastic about the new Serializable Snapshot Isolation of PosgtreSQL 9.1! Synchronous replication and more performance optimizations are two other reasons we are looking forward to the next release of PostgreSQL, truly the epitome of Open Source software," said Olivier Dony, OpenERP Community Manager.
About OpenERP: OpenERP is an open source comprehensive suite of business applications including Sales, CRM, Project management, Warehouse management, Manufacturing, Accounting and Human Resources. OpenERP has separate client and server components. XML-RPC interfaces are available. OpenERP was founded by CEO Fabien Pinckaers in 2005. Fabien's vision was that Open Source provided a better way to meet customers' expectations. Contact: email@example.com