- added caveats to unittest README encountered with Py2.7 + current nose 0.11.3
- call counts for py2.7. all tests pass for sqlite + mysql-python + psycopg2
with convert_unicode=True no longer embeds the actual
value passed. This so that the Python warning
registry does not continue to grow in size, the warning
is emitted once as per the warning filter settings,
and large string values don't pollute the output.
[ticket:1822]
after a dispose() occurs.
- Engine gains an "execution_options" argument and
update_execution_options() method, which will apply to
all connections generated by this engine.
- Added more aggressive caching to the mapper's usage of
UPDATE, INSERT, and DELETE expressions. Assuming the
statement has no per-object SQL expressions attached,
the expression objects are cached by the mapper after
the first create, and their compiled form is stored
persistently in a cache dictionary for the duration of
the related Engine.
- change #3 required change #1 so that we could test
a set of mappers operating over the course of many engines without
memory usage increase.
relationship(), to eliminate confusion over the relational
algebra term. relation() however will remain available
in equal capacity for the foreseeable future. [ticket:1740]
on_connect(). This method returns a callable which receives
the raw DBAPI connection after each one is created. The callable
is assembled into a first_connect/connect pool listener by the
connection strategy if non-None. Provides a simpler interface
for dialects.
logging that remains will respond to live changes in the
log level. No significant overhead is added. [ticket:1719]
- engine: Opened up logging a bit such that isEnabledFor() is called
more often, so that changes to the log level for engine/pool
will be reflected on next connect. This adds a small
amount of method call overhead. It's negligible and will make
life a lot easier for all those situations when logging
just happens to be configured after create_engine() is called.
[ticket:1719]
Behaves like the 'errors' keyword argument to
the standard library's string.decode() functions. This flag
requires that `convert_unicode` is set to `"force"` - otherwise,
SQLAlchemy is not guaranteed to handle the task of unicode
conversion. Note that this flag adds significant performance
overhead to row-fetching operations for backends that already
return unicode objects natively (which most DBAPIs do). This
flag should only be used as an absolute last resort for reading
strings from a column with varied or corrupted encodings,
which only applies to databases that accept invalid encodings
in the first place (i.e. MySQL. *not* PG, Sqlite, etc.)
defined bind parameter name that directly conflicts with
a column-named bind generated directly from the SET or
VALUES clause of an update/insert generates a compile error.
This reduces call counts and eliminates some cases where
undesirable name conflicts could still occur.
reimplementing the highest impact functions.
The actual speedups will depend heavily on your DBAPI and
the mix of datatypes used in your tables, and can vary from
a 50% improvement to more than 200%. It also provides a modest
(~20%) indirect improvement to ORM speed for large queries.
Note that it is *not* built/installed by default.
See README for installation instructions.
- The most common result processors conversion function were
moved to the new "processors" module. Dialect authors are
encouraged to use those functions whenever they correspond
to their needs instead of implementing custom ones.
passed to the resulting statement. Currently only
Select-statements have these options, and the only option
used is "stream_results", and the only dialect which knows
"stream_results" is psycopg2.
- Query.yield_per() will set the "stream_results" statement
option automatically.
- Added "statement_options()" to Selects, which set statement
specific options. These enable e.g. dialect specific options
such as whether to enable using server side cursors, etc.
- The psycopg2 now respects the statement option
"stream_results". This option overrides the connection setting
"server_side_cursors". If true, server side cursors will be
used for the statement. If false, they will not be used, even
if "server_side_cursors" is true on the
connection. [ticket:1619]
- added a "frozendict" from http://code.activestate.com/recipes/414283/,
adding more default collections as immutable class vars on
Query, Insert, Select
given instance is the same instance which is already present.
- merge() now also merges the "options" associated with a given
state, i.e. those passed through query.options() which follow
along with an instance, such as options to eagerly- or
lazyily- load various attributes. This is essential for
the construction of highly integrated caching schemes. This
is a subtle behavioral change vs. 0.5.
- A bug was fixed regarding the serialization of the "loader
path" present on an instance's state, which is also necessary
when combining the usage of merge() with serialized state
and associated options that should be preserved.
- The "query_cache" examples have been removed, and are replaced
with a fully comprehensive approach that combines the usage of
Beaker with SQLAlchemy. New query options are used to indicate
the caching characteristics of a particular Query, which
can also be invoked deep within an object graph when lazily
loading related objects. See /examples/beaker_caching/README.
on all new connections, which allows all String/Text/etc.
types to skip the need to post-process bytestrings into
unicode (an expensive step due to its volume). Other
dialects which return unicode natively (pg8000, zxjdbc)
also skip unicode post-processing.
- String/Text/Unicode types now skip the unicode() check
on each result column value if the dialect has
detected the DBAPI as returning Python unicode objects
natively. This check is issued on first connect
using "SELECT CAST 'some text' AS VARCHAR(10)" or
equivalent, then checking if the returned object
is a Python unicode. This allows vast performance
increases for native-unicode DBAPIs, including
pysqlite/sqlite3, psycopg2, and pg8000.
method call counts when fetching columns that have no
type-level processing applied. Provides a 100% speed
improvement when fetching large result sets with no unicode
conversion. Many thanks to Elixir's Gaëtan de Menten
for this dramatic improvement ! [ticket:1586]
Mike Bayer