Architectures support:

• Hardware: PC, Alpha, SPARC/UltraSPARC, PowerPC, MIPS, VAX, S/390...
• Software: All major UNIX-variants: AIX, BeOS, *BSD, Digital UNIX/Tru64, IRIX, HP UX, Linux, SCO, SunOS/Solaris, NT+Cygwin

Query Language

• Support for much of SQL/92 AND SQL/99, including:
  • SQL99 joins
  • Transactions
  • Foreign Keys
  • SQL92 & SQL99 data types.
  • Sub-selects
  • Unions and intersections
  • Aggregates
  • Views
  • Cursors

• PostgreSQL specific SQL Extensions:
  • Triggers
  • Rules
  • User permission sub-system
  • Sequences
  • Query explanation
  • Procedural language support
  • User-defined functions: SQL, C, Tcl, Ruby, Perl, PL/PgSQL, Python
  • Much more...

Transactions & Multi-version Concurrency Control

• Transactions:
  • Allow work on a database to be encapsulated (BEGIN/COMMIT)
  • Work can be undone to the beginning to the transaction (ROLLBACK/ABORT)
  • Upon error, all work in the transaction is invalidated
  • Increased reliability

• Multi-version Concurrency Control (MVCC)
  • Each database connection sees a snapshot of the database
  • Backends synchronised upon updates/transaction committal
  • Write-ahead logging (WAL): increased reliability
  • Performance of MVCC

Indexing

• B-tree, R-tree, hash and GiST index algorithm support
• Single and multi-column (B-tree only) indexes
• Functional indexes

Extensibility

• User defined functions/procedures, aggregates, types
• Extend PostgreSQL in your language of choice: SQL, C, Perl, PL/PgSQL, Python, Ruby, Tcl

Administration

• Postgres database super-user
• Basic set of administration command line tools: pg_ctl, pg_dump...
• Interactive SQL Console: psql

Licensing

• BSD style license