Psycopg2

-------------------------

psycopg 2.3 aims to expose some new features introduced in PostgreSQL 9.0.

Main new features:

- `dict` to `hstore` adapter and `hstore` to `dict` typecaster, using both
9.0 and pre-9.0 syntax.
- Two-phase commit protocol support as per DBAPI specification.
- Support for payload in notifications received from the backend.
- `namedtuple`-returning cursor.
- Query execution cancel.

Other features and changes:

- Dropped support for protocol 2: Psycopg 2.3 can only connect to PostgreSQL
servers with version at least 7.4.
- Don't issue a query at every connection to detect the client encoding
and to set the datestyle to ISO if it is already compatible with what
expected.
- `mogrify()` now supports unicode queries.
- Subclasses of a type that can be adapted are adapted as the superclass.
- `errorcodes` knows a couple of new codes introduced in PostgreSQL 9.0.
- Dropped deprecated Psycopg "own quoting".
- Never issue a ROLLBACK on close/GC. This behaviour was introduced as a bug
in release 2.2, but trying to send a command while being destroyed has been
considered not safe.

Bug fixes:

- Fixed use of `PQfreemem` instead of `free` in binary typecaster.
- Fixed access to freed memory in `conn_get_isolation_level()`.
- Fixed crash during Decimal adaptation with a few 2.5.x Python versions
(:ticket:`7`).
- Fixed notices order (:ticket:`9`).

^^^^^^^^^^^^^^^^^^^^^^^^^^^

Bux fixes:

- the call to logging.basicConfig() in pool.py has been dropped: it was
messing with some projects using logging (and a library should not
initialize the logging system anyway.)
- psycopg now correctly handles time zones with seconds in the UTC offset.
The old register_tstz_w_secs() function is deprecated and will raise a
warning if called.
- Exceptions raised by the column iterator are propagated.
- Exceptions raised by executemany() iterators are propagated.

^^^^^^^^^^^^^^^^^^^^^^^^^^^

Bux fixes:

- psycopg now builds again on MS Windows.

-------------------------

This is the first release of the new 2.2 series, supporting not just one but
two different ways of executing asynchronous queries, thanks to Jan and Daniele
(with a little help from me and others, but they did 99% of the work so they
deserve their names here in the news.)

psycopg now supports both classic select() loops and "green" coroutine
libraries. It is all in the documentation, so just point your browser to
doc/html/advanced.html.

Other new features:

- truncate() method for lobjects.
- COPY functions are now a little bit faster.
- All builtin PostgreSQL to Python typecasters are now available from the
psycopg2.extensions module.
- Notifications from the backend are now available right after the execute()
call (before client code needed to call isbusy() to ensure NOTIFY
reception.)
- Better timezone support.
- Lots of documentation updates.

Bug fixes:

- Fixed some gc/refcounting problems.
- Fixed reference leak in NOTIFY reception.
- Fixed problem with PostgreSQL not casting string literals to the correct
types in some situations: psycopg now add an explicit cast to dates, times
and bytea representations.
- Fixed TimestampFromTicks() and TimeFromTicks() for seconds >= 59.5.
- Fixed spurious exception raised when calling C typecasters from Python
ones.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^

New features:

- Support for adapting tuples to PostgreSQL arrays is now enabled by
default and does not require importing psycopg2.extensions anymore.
- "can't adapt" error message now includes full type information.
- Thank to Daniele Varrazzo (piro) psycopg2's source package now includes
full documentation in HTML and plain text format.

Bug fixes:

- No loss of precision when using floats anymore.
- decimal.Decimal "nan" and "infinity" correctly converted to PostgreSQL
numeric NaN values (note that PostgreSQL numeric type does not support
infinity but just NaNs.)
- psycopg2.extensions now includes Binary.

It seems we're good citizens of the free software ecosystem and that big
big big companies and people ranting on the pgsql-hackers mailing list
we'll now not dislike us. *g* (See LICENSE file for the details.)

^^^^^^^^^^^^^^^^^^^^^^^^^^^^

New features:

- Support for UUID arrays.
- It is now possible to build psycopg linking to a static libpq
library.

Bug fixes:

- Fixed a deadlock related to using the same connection with
multiple cursors from different threads.
- Builds again with MSVC.