cx_Oracle Release Notes¶
Version 6.1 (December 2017)¶
- Update to ODPI-C 2.1.
- Support was added for accessing sharded databases via sharding keys (new in Oracle 12.2). NOTE: the underlying OCI library has a bug when using standalone connections. There is a small memory leak proportional to the number of connections created/dropped. There is no memory leak when using session pools, which is recommended.
- Added options for authentication with SYSBACKUP, SYSDG, SYSKM and SYSRAC, as requested (issue 101).
- Attempts to release statements or free LOBs after the connection has been closed (by, for example, killing the session) are now prevented.
- An error message was added when specifying an edition and a connection class since this combination is not supported.
- Attempts to close the session for connections created with an external handle are now prevented.
- Attempting to ping a database earlier than 10g results in ORA-1010: invalid OCI operation, but that implies a response from the database and therefore a successful ping, so treat it that way! (see https://github.com/rana/ora/issues/224 for more information).
- Support was added for converting numeric values in an object type attribute to integer and text, as requested (ODPI-C issue 35).
- Setting attributes
MessageProperties.msgIdnow works as expected.
- The overflow check when using double values (Python floats) as input to float attributes of objects or elements of collections was removed as it didn’t work anyway and is a well-known issue that cannot be prevented without removing desired functionality. The developer should ensure that the source value falls within the limits of floats, understand the consequent precision loss or use a different data type.
- Variables of string/raw types are restricted to 2 bytes less than 1 GB (1,073,741,822 bytes), since OCI cannot handle more than that currently.
- Support was added for identifying the id of the transaction which spawned a subscription message, as requested (ODPI-C issue 32).
- Corrected use of subscription port number (issue 115).
- Problems reported with the usage of FormatMessage() on Windows were addressed (ODPI-C issue 47).
- On Windows, if oci.dll cannot be loaded because it is the wrong architecture (32-bit vs 64-bit), attempt to find the offending DLL and include the full path of the DLL in the message, as suggested. (ODPI-C issue 49).
- Force OCI prefetch to always use the value 2; the OCI default is 1 but setting the ODPI-C default to 2 ensures that single row fetches don’t require an extra round trip to determine if there are more rows to fetch; this change also reduces the potential memory consumption when fetchArraySize was set to a large value and also avoids performance issues discovered with larger values of prefetch.
- Fix build with PyPy 5.9.0-alpha0 in libpython mode (PR 54).
- Ensure that the edition is passed through to the database when a session pool is created.
- Corrected handling of Python object references when an invalid keyword
parameter is passed to
- Corrected handling of
Connection.handleand the handle parameter to
- Documentation improvements.
- Added test cases to the test suite.
Version 6.0.3 (November 2017)¶
- Update to ODPI-C 2.0.3.
- Prevent use of unitialized data in certain cases (issue 77).
- Attempting to ping a database earlier than 10g results in error “ORA-1010: invalid OCI operation”, but that implies a response from the database and therefore a successful ping, so treat it that way!
- Correct handling of conversion of some numbers to NATIVE_FLOAT.
- Prevent use of NaN with Oracle numbers since it produces corrupt data (issue 91).
- Verify that Oracle objects bound to cursors, fetched from cursors, set in object attributes or appended to collection objects are of the correct type.
- Correct handling of NVARCHAR2 when used as attributes of Oracle objects or as elements of collections.
- Ensure that a call to setinputsizes() with an invalid type prior to a call to executemany() does not result in a type error, but instead gracefully ignores the call to setinputsizes() as required by the DB API (https://github.com/oracle/python-cx_Oracle/issues/75).
- Check variable array size when setting variable values and raise IndexError, as is already done for getting variable values.
Version 6.0.2 (August 2017)¶
- Update to ODPI-C 2.0.2.
- Don’t prevent connection from being explicitly closed when a fatal error has taken place (issue 67).
- Correct handling of objects when dynamic binding is performed.
- Process deregistration events without an error.
- Eliminate memory leak when creating objects.
- Added missing type check to prevent coercion of decimal to float (issue 68).
- On Windows, sizeof(long) = 4, not 8, which meant that integers between 10 and 18 digits were not converted to Python correctly (issue 70).
- Eliminate memory leak when repeatedly executing the same query.
- Eliminate segfault when attempting to reuse a REF cursor that has been closed.
- Updated documentation.
Version 6.0.1 (August 2017)¶
- Update to ODPI-C 2.0.1.
- Ensure that queries registered via
Subscription.registerquery()do not prevent the associated connection from being closed (ODPI-C issue 27).
- Deprecated attribute
Subscription.idas it was never intended to be exposed (ODPI-C issue 28). It will be dropped in version 6.1.
- Add support for DML returning statements that require dynamically allocated variable data (such as CLOBs being returned as strings).
- Ensure that queries registered via
- Correct packaging of Python 2.7 UCS4 wheels on Linux (issue 64).
- Updated documentation.
Version 6.0 (August 2017)¶
- Update to ODPI-C 2.0.
- Prevent closing the connection when there are any open statements or LOBs and add new error “DPI-1054: connection cannot be closed when open statements or LOBs exist” when this situation is detected; this is needed to prevent crashes under certain conditions when statements or LOBs are being acted upon while at the same time (in another thread) a connection is being closed; it also prevents leaks of statements and LOBs when a connection is returned to a session pool.
- On platforms other than Windows, if the regular method for loading the Oracle Client libraries fails, try using $ORACLE_HOME/lib/libclntsh.so (ODPI-C issue 20).
- Use the environment variable DPI_DEBUG_LEVEL at runtime, not compile time.
- Added support for DPI_DEBUG_LEVEL_ERRORS (reports errors and has the value 8) and DPI_DEBUG_LEVEL_SQL (reports prepared SQL statement text and has the value 16) in order to further improve the ability to debug issues.
- Correct processing of
Cursor.scroll()in some circumstances.
- Delay initialization of the ODPI-C library until the first standalone connection or session pool is created so that manipulation of the environment variable NLS_LANG can be performed after the module has been imported; this also has the added benefit of reducing the number of errors that can take place when the module is imported.
- Prevent binding of null values from generating the exception “ORA-24816: Expanded non LONG bind data supplied after actual LONG or LOB column” in certain circumstances (issue 50).
- Added information on how to run the test suite (issue 33).
- Documentation improvements.
Version 6.0 rc 2 (July 2017)¶
- Update to ODPI-C rc 2.
- Provide improved error message when OCI environment cannot be created, such as when the oraaccess.xml file cannot be processed properly.
- On Windows, convert system message to Unicode first, then to UTF-8; otherwise, the error message returned could be in a mix of encodings (issue 40).
- Corrected support for binding decimal values in object attribute values and collection element values.
- Corrected support for binding PL/SQL boolean values to PL/SQL procedures with Oracle client 11.2.
- Define exception classes on the connection object in addition to at module scope in order to simplify error handling in multi-connection environments, as specified in the Python DB API.
- Ensure the correct encoding is used for setting variable values.
- Corrected handling of CLOB/NCLOB when using different encodings.
- Corrected handling of TIMESTAMP WITH TIME ZONE attributes on objects.
- Ensure that the array position passed to var.getvalue() does not exceed the number of elements allocated in the array.
- Reworked test suite and samples so that they are independent of each other and so that the SQL scripts used to create/drop schemas are easily adjusted to use different schema names, if desired.
- Updated DB API test suite stub to support Python 3.
- Added additional test cases and samples.
- Documentation improvements.
Version 6.0 rc 1 (June 2017)¶
- Update to ODPI-C rc 1.
- The method
Cursor.setoutputsize()no longer needs to do anything, since ODPI-C automatically manages buffer sizes of LONG and LONG RAW columns.
- Handle case when both precision and scale are zero, as occurs when retrieving numeric expressions (issue 34).
- OCI requires that both encoding and nencoding have values or that both
encoding and encoding do not have values. These parameters are used in
cx_Oracle.SessionPool(). The missing value is set to its default value if one of the values is set and the other is not (issue 36).
- Permit use of both string and unicode for Python 2.7 for creating session pools and for changing passwords (issue 23).
- Corrected handling of BFILE LOBs.
- Add script for dropping test schemas.
- Documentation improvements.
Version 6.0 beta 2 (May 2017)¶
- Added support for getting/setting attributes of objects or element values in collections that contain LOBs, BINARY_FLOAT values, BINARY_DOUBLE values and NCHAR and NVARCHAR2 values. The error message for any types that are not supported has been improved as well.
- Enable temporary LOB caching in order to avoid disk I/O as suggested.
- Added support for setting the debug level in ODPI-C, if desirable, by setting environment variable DPI_DEBUG_LEVEL prior to building cx_Oracle.
- Correct processing of strings in
Cursor.executemany()when a larger string is found after a shorter string in the list of data bound to the statement.
- Correct handling of long Python integers that cannot fit inside a 64-bit C integer (issue 18).
- Correct creation of pool using external authentication.
- Handle edge case when an odd number of zeroes trail the decimal point in a value that is effectively zero (issue 22).
- Prevent segfault under load when the attempt to create an error fails.
- Eliminate resource leak when a standalone connection or pool is freed.
- Correct typo.
- Correct handling of REF cursors when the array size is manipulated.
- Prevent attempts from binding the cursor being executed to itself.
- Correct reference count handling of parameters when creating a cursor.
- Correct determination of the names of the bind variables in prepared SQL statements (which behaves a little differently from PL/SQL statements).
Version 6.0 beta 1 (April 2017)¶
- Simplify building cx_Oracle considerably by use of ODPI-C. This means that cx_Oracle can now be built without Oracle Client header files or libraries and that at runtime cx_Oracle can adapt to Oracle Client 11.2, 12.1 or 12.2 libraries without needing to be rebuilt. This also means that wheels can now be produced and installed via pip.
- Added attribute
SessionPool.stmtcachesizeto support getting and setting the default statement cache size for connections in the pool.
- Added attribute
Connection.dbopto support setting the database operation that is to be monitored.
- Added attribute
Connection.handleto facilitate testing the creation of a connection using a OCI service context handle.
- Added parameters tag and matchanytag to the
SessionPool.acquire()methods and added parameters tag and retag to the
SessionPool.release()method in order to support session tagging.
- Added parameter edition to the
- Added support for universal rowids.
- Added support for DML returning of multiple rows.
- Added attributes
- Added parameters region, sharding_key and super_sharding_key to the
cx_Oracle.makedsn()method to support connecting to a sharded database (new in Oracle Database 12.2).
- Added support for smallint and float data types in Oracle objects, as requested.
- An exception is no longer raised when a collection is empty for methods
Object.last(). Instead, the value None is returned to be consistent with the methods
- If the environment variables NLS_LANG and NLS_NCHAR are being used, they
must be set before the module is imported. Using the encoding and nencoding
parameters to the
cx_Oracle.SessionPool()methods is a simpler alternative to setting these environment variables.
- Removed restriction on fetching LOBs across round trips to the database (eliminates error “LOB variable no longer valid after subsequent fetch”).
- Removed requirement for specifying a maximum size when fetching LONG or LONG raw columns. This also allows CLOB, NCLOB, BLOB and BFILE columns to be fetched as strings or bytes without needing to specify a maximum size.
- Dropped deprecated parameter twophase from the
cx_Oracle.connect()method. Applications should set the
Connection.external_nameattributes instead to a value appropriate to the application.
- Dropped deprecated parameters action, module and clientinfo from the
cx_Oracle.connect()method. The appcontext parameter should be used instead as shown in this sample.
- Dropped deprecated attribute numbersAsString from cursor objects. Use an output type handler instead as shown in this sample.
- Dropped deprecated attributes cqqos and rowids from subscription objects. Use the qos attribute instead as shown in this sample.
- Dropped deprecated parameters cqqos and rowids from the
Connection.subscribe()method. Use the qos parameter instead as shown in this sample.
Version 5.3 (March 2017)¶
- Added support for Python 3.6.
- Dropped support for Python versions earlier than 2.6.
- Dropped support for Oracle clients earlier than 11.2.
- Added support for
fetching implicit results(available in Oracle 12.1)
- Added support for
Transaction Guard(available in Oracle 12.1).
- Added support for setting the
maximum lifetimeof pool connections (available in Oracle 12.1).
- Added support for large row counts (larger than 2 ** 32, available in Oracle 12.1)
- Added support for
- Added support for
- Added support for
edition based redefinition.
- Added support for
creating, modifying and binding user defined types and collections.
- Added support for creating, modifying and binding PL/SQL records and collections (available in Oracle 12.1).
- Added support for binding
- Enabled statement caching.
- Removed deprecated variable attributes maxlength and allocelems.
- Corrected support for setting the encoding and nencoding parameters when
creating a connectionand added support for setting these when creating a session pool. These can now be used instead of setting the environment variables NLS_LANG and NLS_NCHAR.
- Use None instead of 0 for items in the
Cursor.descriptionattribute that do not have any validity.
- Changed driver name to match informal driver name standard used by Oracle for other drivers.
- Add check for maximum of 10,000 parameters when calling a stored procedure or function in order to prevent a possible improper memory access from taking place.
- Removed -mno-cygwin compile flag since it is no longer used in newer versions of the gcc compiler for Cygwin.
- Simplified test suite by combining Python 2 and 3 scripts into one script and separated out 12.1 features into a single script.
- Updated samples to use code that works on both Python 2 and 3
- Added support for pickling/unpickling error objects (Issue #23)
- Dropped support for callbacks on OCI functions.
- Removed deprecated types UNICODE, FIXED_UNICODE and LONG_UNICODE (use NCHAR, FIXED_NCHAR and LONG_NCHAR instead).
- Increased default array size to 100 (from 50) to match other drivers.
- Added support for setting the
external_nameon the connection directly. The use of the twophase parameter is now deprecated. Applications should set the internal_name and external_name attributes directly to a value appropriate to the application.
- Added support for using application context when
creating a connection. This should be used in preference to the module, action and clientinfo parameters which are now deprecated.
- Reworked database change notification and continuous query notification to
more closely align with the PL/SQL implementation and prepare for sending
notifications for AQ messages. The following changes were made:
- added constant
SUBSCR_QOS_BEST_EFFORTto replace deprecated constant SUBSCR_CQ_QOS_BEST_EFFORT
- added constant
SUBSCR_QOS_QUERYto replace deprecated constant SUBSCR_CQ_QOS_QUERY
- added constant
SUBSCR_QOS_DEREG_NFYto replace deprecated constant SUBSCR_QOS_PURGE_ON_NTFN
- added constant
SUBSCR_QOS_ROWIDSto replace parameter rowids for method
- deprecated parameter cqqos for method
Connection.subscribe(). The qos parameter should be used instead.
- dropped constants SUBSCR_CQ_QOS_CLQRYCACHE, SUBSCR_QOS_HAREG, SUBSCR_QOS_MULTICBK, SUBSCR_QOS_PAYLOAD, SUBSCR_QOS_REPLICATE, and SUBSCR_QOS_SECURE since they were never actually used
- added constant
- Deprecated use of the numbersAsStrings attribute on cursors. An output type handler should be used instead.
Version 5.2.1 (January 2016)¶
- Added support for Python 3.5.
- Removed password attribute from connection and session pool objects in order to promote best security practices (if stored in RAM in cleartext it can be read in process dumps, for example). For those who would like to retain this feature, a subclass of Connection could be used to store the password.
- Added optional parameter externalauth to SessionPool() which enables wallet based or other external authentication mechanisms to be used.
- Use the national character set encoding when required (when char set form is SQLCS_NCHAR); otherwise, the wrong encoding would be used if the environment variable NLS_NCHAR is set.
- Added support for binding boolean values to PL/SQL blocks and stored procedures (available in Oracle 12.1).
Version 5.2 (June 2015)¶
- Added support for strings up to 32k characters (new in Oracle 12c).
- Added support for getting array DML row counts (new in Oracle 12c).
- Added support for fetching batch errors.
- Added support for LOB values larger than 4 GB.
- Added support for connections as SYSASM.
- Added support for building without any configuration changes to the machine when using instant client RPMs on Linux.
- Added types NCHAR, FIXED_NCHAR and LONG_NCHAR to replace the types UNICODE, FIXED_UNICODE and LONG_UNICODE (which are now deprecated). These types are available in Python 3 as well so they can be used to specify the use of NCHAR type fields when binding or using setinputsizes().
- Fixed binding of booleans in Python 3.x.
- Test suite now sets NLS_LANG if not already set.
- Enhanced documentation for connection.action attribute and added note on cursor.parse() method to make clear that DDL statements are executed when parsed.
- Removed remaining remnants of support Oracle 9i.
- Added __version__ attribute to conform with PEP 396.
- Ensure that sessions are released to the pool when calling connection.close() (Issue #2)
- Fixed handling of datetime intervals (Issue #7)
Version 5.1.3 (May 2014)¶
- Added support for Oracle 12c.
- Added support for Python 3.4.
- Added support for query result set change notification. Thanks to Glen Walker for the patch.
- Ensure that in Python 3.x that NCHAR and NVARCHAR2 and NCLOB columns are retrieved properly without conversion issues. Thanks to Joakim Andersson for pointing out the issue and the possible solution.
- Fix bug when an exception is caught and then another exception is raised while handling that exception in Python 3.x. Thanks to Boris Dzuba for pointing out the issue and providing a test case.
- Enhance performance returning integers between 10 and 18 digits on 64-bit platforms that support it. Thanks for Shai Berger for the initial patch.
- Fixed two memory leaks.
- Fix to stop current_schema from throwing a MemoryError on 64-bit platforms on occasion. Thanks to Andrew Horton for the fix.
- Class name of cursors changed to real name cx_Oracle.Cursor.
Version 5.1.2 (July 2012)¶
- Added support for LONG_UNICODE which is a type used to handle long unicode strings. These are not explicitly supported in Oracle but can be used to bind to NCLOB, for example, without getting the error “unimplemented or unreasonable conversion requested”.
- Set the row number in a cursor when executing PL/SQL blocks as requested by Robert Ritchie.
- Added support for setting the module, action and client_info attributes during connection so that logon triggers will see the supplied values, as requested by Rodney Barnett.
Version 5.1.1 (October 2011)¶
- Simplify management of threads for callbacks performed by database change notification and eliminate a crash that occurred under high load in certain situations. Thanks to Calvin S. for noting the issue and suggesting a solution and testing the patch.
- Force server detach on close so that the connection is completely closed and not just the session as before.
- Force use of OCI_UTF16ID for NCLOBs as using the default character set would result in ORA-03127 with Oracle 18.104.22.168 and UTF8 character set.
- Avoid attempting to clear temporary LOBs a second time when destroying the variable as in certain situations this results in spurious errors.
- Added additional parameter service_name to makedsn() which can be used to use the service_name rather than the SID in the DSN string that is generated.
- Fix cursor description in test suite to take into account the number of bytes per character.
- Added tests for NCLOBS to the test suite.
- Removed redundant code in setup.py for calculating the library path.
Version 5.1 (March 2011)¶
- Remove support for UNICODE mode and permit Unicode to be passed through in everywhere a string may be passed in. This means that strings will be passed through to Oracle using the value of the NLS_LANG environment variable in Python 3.x as well. Doing this eliminated a bunch of problems that were discovered by using UNICODE mode and also removed an unnecessary restriction in Python 2.x that Unicode could not be used in connect strings or SQL statements, for example.
- Added support for creating an empty object variable via a named type, the first step to adding full object support.
- Added support for Python 3.2.
- Account for lib64 used on x86_64 systems. Thanks to Alex Wood for supplying the patch.
- Clear up potential problems when calling cursor.close() ahead of the cursor being freed by going out of scope.
- Avoid compilation difficulties on AIX5 as OCIPing does not appear to be available on that platform under Oracle 10g Release 2. Thanks to Pierre-Yves Fontaniere for the patch.
- Free temporary LOBs prior to each fetch in order to avoid leaking them. Thanks to Uwe Hoffmann for the initial patch.
Version 5.0.4 (July 2010)¶
- Added support for Python 2.7.
- Added support for new parameter (port) for subscription() call which allows the client to specify the listening port for callback notifications from the database server. Thanks to Geoffrey Weber for the initial patch.
- Fixed compilation under Oracle 9i.
- Fixed a few error messages.
Version 5.0.3 (February 2010)¶
- Added support for 64-bit Windows.
- Added support for Python 3.1 and dropped support for Python 3.0.
- Added support for keyword parameters in cursor.callproc() and cursor.callfunc().
- Added documentation for the UNICODE and FIXED_UNICODE variable types.
- Added extra link arguments required for Mac OS X as suggested by Jason Woodward.
- Added additional error codes to the list of error codes that raise OperationalError rather than DatabaseError.
- Fixed calculation of display size for strings with national database character sets that are not the default AL16UTF16.
- Moved the resetting of the setinputsizes flag before the binding takes place so that if an error takes place and a new statement is prepared subsequently, spurious errors will not occur.
- Fixed compilation with Oracle 10g Release 1.
- Tweaked documentation based on feedback from a number of people.
- Added support for running the test suite using “python setup.py test”
- Added support for setting the CLIENT_IDENTIFIER value in the v$session table for connections.
- Added exception when attempting to call executemany() with arrays which is not supported by the OCI.
- Fixed bug when converting from decimal would result in OCI-22062 because the locale decimal point was not a period. Thanks to Amaury Forgeot d’Arc for the solution to this problem.
Version 5.0.2 (May 2009)¶
- Fix creation of temporary NCLOB values and the writing of NCLOB values in non Unicode mode.
- Re-enabled parsing of non select statements as requested by Roy Terrill.
- Implemented a parse error offset as requested by Catherine Devlin.
- Removed lib subdirectory when forcing RPATH now that the library directory is being calculated exactly in setup.py.
- Added an additional cast in order to support compiling by Microsoft Visual C++ 2008 as requested by Marco de Paoli.
- Added additional include directory to setup.py in order to support compiling by Microsoft Visual Studio was requested by Jason Coombs.
- Fixed a few documentation issues.
Version 5.0.1 (February 2009)¶
- Added support for database change notification available in Oracle 10g Release 2 and higher.
- Fix bug where NCLOB data would be corrupted upon retrieval (non Unicode mode) or would generate exception ORA-24806 (LOB form mismatch). Oracle insists upon differentiating between CLOB and NCLOB no matter which character set is being used for retrieval.
- Add new attributes size, bufferSize and numElements to variable objects, deprecating allocelems (replaced by numElements) and maxlength (replaced by bufferSize)
- Avoid increasing memory allocation for strings when using variable width character sets and increasing the number of elements in a variable during executemany().
- Tweaked code in order to ensure that cx_Oracle can compile with Python 3.0.1.
Version 5.0 (December 2008)¶
- Added support for Python 3.0 with much help from Amaury Forgeot d’Arc.
- Removed support for Python 2.3 and Oracle 8i.
- Added support for full unicode mode in Python 2.x where all strings are passed in and returned as unicode (module must be built in this mode) rather than encoded strings
- nchar and nvarchar columns now return unicode instead of encoded strings
- Added support for an output type handler and/or an input type handler to be specified at the connection and cursor levels.
- Added support for specifying both input and output converters for variables
- Added support for specifying the array size of variables that are created using the cursor.var() method
- Added support for events mode and database resident connection pooling (DRCP) in Oracle 11g.
- Added support for changing the password during construction of a new connection object as well as after the connection object has been created
- Added support for the interval day to second data type in Oracle, represented as datetime.timedelta objects in Python.
- Added support for getting and setting the current_schema attribute for a session
- Added support for proxy authentication in session pools as requested by Michael Wegrzynek (and thanks for the initial patch as well).
- Modified connection.prepare() to return a boolean indicating if a transaction was actually prepared in order to avoid the error ORA-24756 (transaction does not exist).
- Raise a cx_Oracle.Error instance rather than a string for column truncation errors as requested by Helge Tesdal.
- Fixed handling of environment handles in session pools in order to allow session pools to fetch objects without exceptions taking place.
Version 4.4.1 (October 2008)¶
- Make the bind variables and fetch variables accessible although they need to be treated carefully since they are used internally; support added for forward compatibility with version 5.x.
- Include the “cannot insert null value” in the list of errors that are treated as integrity errors as requested by Matt Boersma.
- Use a cx_Oracle.Error instance rather than a string to hold the error when truncation (ORA-1406) takes place as requested by Helge Tesdal.
- Added support for fixed char, old style varchar and timestamp attribute values in objects.
- Tweaked setup.py to check for the Oracle version up front rather than during the build in order to produce more meaningful errors and simplify the code.
- In setup.py added proper detection for the instant client on Mac OS X as recommended by Martijn Pieters.
- In setup.py, avoided resetting the extraLinkArgs on Mac OS X as doing so prevents simple modification where desired as expressed by Christian Zagrodnick.
- Added documentation on exception handling as requested by Andreas Mock, who also graciously provided an initial patch.
- Modified documentation indicating that the password attribute on connection objects can be written.
- Added documentation warning that parameters not passed in during subsequent executions of a statement will retain their original values as requested by Harald Armin Massa.
- Added comments indicating that an Oracle client is required since so many people find this surprising.
- Removed all references to Oracle 8i from the documentation and version 5.x will eliminate all vestiges of support for this version of the Oracle client.
- Added additional link arguments for Cygwin as requested by Rob Gillen.
Version 4.4 (June 2008)¶
- Fix setup.py to handle the Oracle instant client and Oracle XE on both Linux and Windows as pointed out by many. Thanks also to the many people who also provided patches.
- Set the default array size to 50 instead of 1 as the DB API suggests because the performance difference is so drastic and many people have recommended that the default be changed.
- Added Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS around each blocking call for LOBs as requested by Jason Conroy who also provided an initial patch and performed a number of tests that demonstrate the new code is much more responsive.
- Add support for acquiring cursor.description after a parse.
- Defer type assignment when performing executemany() until the last possible moment if the value being bound in is null as suggested by Dragos Dociu.
- When dropping a connection from the pool, ignore any errors that occur during the rollback; unfortunately, Oracle decides to commit data even when dropping a connection from the pool instead of rolling it back so the attempt still has to be made.
- Added support for setting CLIENT_DRIVER in V$SESSION_CONNECT_INFO in Oracle 11g and higher.
- Use cx_Oracle.InterfaceError rather than the builtin RuntimeError when unable to create the Oracle environment object as requested by Luke Mewburn since the error is specific to Oracle and someone attempting to catch any exception cannot simply use cx_Oracle.Error.
- Translated some error codes to OperationalError as requested by Matthew Harriger; translated if/elseif/else logic to switch statement to make it more readable and to allow for additional translation if desired.
- Transformed documentation to new format using restructured text. Thanks to Waldemar Osuch for contributing the initial draft of the new documentation.
- Allow the password to be overwritten by a new value as requested by Alex VanderWoude; this value is retained as a convenience to the user and not used by anything in the module; if changed externally it may be convenient to keep this copy up to date.
- Cygwin is on Windows so should be treated in the same way as noted by Matthew Cahn.
- Add support for using setuptools if so desired as requested by Shreya Bhatt.
- Specify that the version of Oracle 10 that is now primarily used is 10.2, not 10.1.
Version 4.3.3 (October 2007)¶
- Added method ping() on connections which can be used to test whether or not a connection is still active (available in Oracle 10g R2).
- Added method cx_Oracle.clientversion() which returns a 5-tuple giving the version of the client that is in use (available in Oracle 10g R2).
- Added methods startup() and shutdown() on connections which can be used to startup and shutdown databases (available in Oracle 10g R2).
- Added support for Oracle 11g.
- Added samples directory which contains a handful of scripts containing sample code for more advanced techniques. More will follow in future releases.
- Prevent error “ORA-24333: zero iteration count” when calling executemany() with zero rows as requested by Andreas Mock.
- Added methods __enter__() and __exit__() on connections to support using connections as context managers in Python 2.5 and higher. The context managed is the transaction state. Upon exit the transaction is either rolled back or committed depending on whether an exception took place or not.
- Make the search for the lib32 and lib64 directories automatic for all platforms.
- Tweak the setup configuration script to include all of the metadata and allow for building the module within another setup configuration script
- Include the Oracle version in addition to the Python version in the build directories that are created and in the names of the binary packages that are created.
- Remove unnecessary dependency on win32api to build module on Windows.
Version 4.3.2 (August 2007)¶
- Added methods open(), close(), isopen() and getchunksize() in order to improve performance of reading/writing LOB values in chunks.
- Fixed support for native doubles and floats in Oracle 10g; added new type NATIVE_FLOAT to allow specification of a variable of that specific type where desired. Thanks to D.R. Boxhoorn for pointing out the fact that this was not working properly when the arraysize was anything other than 1.
- When calling connection.begin(), only create a new tranasction handle if one is not already associated with the connection. Thanks to Andreas Mock for discovering this and for Amaury Forgeot d’Arc for diagnosing the problem and pointing the way to a solution.
- Added attribute cursor.rowfactory which allows a method to be called for each row that is returned; this is about 20% faster than calling the method in Python using the idiom [method(*r) for r in cursor].
- Attempt to locate an Oracle installation by looking at the PATH if the environment variable ORACLE_HOME is not set; this is of primary use on Windows where this variable should not normally be set.
- Added support for autocommit mode as requested by Ian Kelly.
- Added support for connection.stmtcachesize which allows for both reading and writing the size of the statement cache size. This parameter can make a huge difference with the length of time taken to prepare statements. Added support for setting the statement tag when preparing a statement. Both of these were requested by Bjorn Sandberg who also provided an initial patch.
- When copying the value of a variable, copy the return code as well.
Version 4.3.1 (April 2007)¶
- Ensure that if the client buffer size exceeds 4000 bytes that the server buffer size does not as strings may only contain 4000 bytes; this allows handling of multibyte character sets on the server as well as the client.
- Added support for using buffer objects to populate binary data and made the Binary() constructor the buffer type as requested by Ken Mason.
- Fix potential crash when using full optimization with some compilers. Thanks to Aris Motas for noticing this and providing the initial patch and to Amaury Forgeot d’Arc for providing an even simpler solution.
- Pass the correct charset form in to the write call in order to support writing to national character set LOB values properly. Thanks to Ian Kelly for noticing this discrepancy.
Version 4.3 (March 2007)¶
- Added preliminary support for fetching Oracle objects (SQL types) as requested by Kristof Beyls (who kindly provided an initial patch). Additional work needs to be done to support binding and updating objects but the basic structure is now in place.
- Added connection.maxBytesPerCharacter which indicates the maximum number of bytes each character can use; use this value to also determine the size of local buffers in order to handle discrepancies between the client character set and the server character set. Thanks to Andreas Mock for providing the initial patch and working with me to resolve this issue.
- Added support for querying native floats in Oracle 10g as requested by Danny Boxhoorn.
- Add support for temporary LOB variables created via PL/SQL instead of only directly by cx_Oracle; thanks to Henning von Bargen for discovering this problem.
- Added support for specifying variable types using the builtin types int, float, str and datetime.date which allows for finer control of what type of Python object is returned from cursor.callfunc() for example.
- Added support for passing booleans to callproc() and callfunc() as requested by Anana Aiyer.
- Fixed support for 64-bit environments in Python 2.5.
- Thanks to Filip Ballegeer and a number of his co-workers, an intermittent crash was tracked down; specifically, if a connection is closed, then the call to OCIStmtRelease() will free memory twice. Preventing the call when the connection is closed solves the problem.
Version 4.2.1 (September 2006)¶
- Added additional type (NCLOB) to handle CLOBs that use the national character set as requested by Chris Dunscombe.
- Added support for returning cursors from functions as requested by Daniel Steinmann.
- Added support for getting/setting the “get” mode on session pools as requested by Anand Aiyer.
- Added support for binding subclassed cursors.
- Fixed binding of decimal objects with absolute values less than 0.1.
Version 4.2 (July 2006)¶
- Added support for parsing an Oracle statement as requested by Patrick Blackwill.
- Added support for BFILEs at the request of Matthew Cahn.
- Added support for binding decimal.Decimal objects to cursors.
- Added support for reading from NCLOBs as requested by Chris Dunscombe.
- Added connection attributes encoding and nencoding which return the IANA character set name for the character set and national character set in use by the client.
- Rework module initialization to use the techniques recommended by the Python documentation as one user was experiencing random segfaults due to the use of the module dictionary after the initialization was complete.
- Removed support for the OPT_Threading attribute. Use the threaded keyword when creating connections and session pools instead.
- Removed support for the OPT_NumbersAsStrings attribute. Use the numbersAsStrings attribute on cursors instead.
- Use type long rather than type int in order to support long integers on 64-bit machines as reported by Uwe Hoffmann.
- Add cursor attribute “bindarraysize” which is defaulted to 1 and is used to determine the size of the arrays created for bind variables.
- Added repr() methods to provide something a little more useful than the standard type name and memory address.
- Added keyword parameter support to the functions that imply such in the documentation as requested by Harald Armin Massa.
- Treat an empty dictionary passed through to cursor.execute() as keyword parameters the same as if no keyword parameters were specified at all, as requested by Fabien Grumelard.
- Fixed memory leak when a LOB read would fail.
- Set the LDFLAGS value in the environment rather than directly in the setup.py file in order to satisfy those who wish to enable the use of debugging symbols.
- Use __DATE__ and __TIME__ to determine the date and time of the build rather than passing it through directly.
- Use Oracle types and add casts to reduce warnings as requested by Amaury Forgeot d’Arc.
- Fixed typo in error message.
Version 4.1.2 (December 2005)¶
- Restore support of Oracle 9i features when using the Oracle 10g client.
Version 4.1.1 (December 2005)¶
- Add support for dropping a connection from a session pool.
- Add support for write only attributes “module”, “action” and “clientinfo” which work only in Oracle 10g as requested by Egor Starostin.
- Add support for pickling database errors.
- Use the previously created bind variable as a template if available when creating a new variable of a larger size. Thanks to Ted Skolnick for the initial patch.
- Fixed tests to work properly in the Python 2.4 environment where dates and timestamps are different Python types. Thanks to Henning von Bargen for pointing this out.
- Added additional directories to search for include files and libraries in order to better support the Oracle 10g instant client.
- Set the internal fetch number to 0 in order to satisfy very picky source analysis tools as requested by Amaury Fogeot d’Arc.
- Improve the documentation for building and installing the module from source as some people are unaware of the standard methods for building Python modules using distutils.
- Added note in the documentation indicating that the arraysize attribute can drastically affect performance of queries since this seems to be a common misunderstanding of first time users of cx_Oracle.
- Add a comment indicating that on HP-UX Itanium with Oracle 10g the library ttsh10 must alos be linked against. Thanks to Bernard Delmee for the information.
Version 4.1 (January 2005)¶
- Fixed bug where subclasses of Cursor do not pass the connection in the constructor causing a segfault.
- DDL statements must be reparsed before execution as noted by Mihai Ibanescu.
- Add support for setting input sizes by position.
- Fixed problem with catching an exception during execute and then still attempting to perform a fetch afterwards as noted by Leith Parkin.
- Rename the types so that they can be pickled and unpickled. Thanks to Harri Pasanen for pointing out the problem.
- Handle invalid NLS_LANG setting properly (Oracle seems to like to provide a handle back even though it is invalid) and determine the number of bytes per character in order to allow for proper support in the future of multibyte and variable width character sets.
- Remove date checking from the native case since Python already checks that dates are valid; enhance error message when invalid dates are encountered so that additional processing can be done.
- Fix bug executing SQL using numeric parameter names with predefined variables (such as what takes place when calling stored procedures with out parameters).
- Add support for reading CLOB values using multibyte or variable length character sets.
Version 4.1 beta 1 (September 2004)¶
- Added support for Python 2.4. In Python 2.4, the datetime module is used for both binding and fetching of date and timestamp data. In Python 2.3, objects from the datetime module can be bound but the internal datetime objects will be returned from queries.
- Added pickling support for LOB and datetime data.
- Fully qualified the table name that was missing in an alter table statement in the setup test script as noted by Marc Gehling.
- Added a section allowing for the setting of the RPATH linker directive in setup.py as requested by Iustin Pop.
- Added code to raise a programming error exception when an attempt is made to access a LOB locator variable in a subsequent fetch.
- The username, password and dsn (tnsentry) are stored on the connection object when specified, regardless of whether or not a standard connection takes place.
- Added additional module level constant called “LOB” as requested by Joseph Canedo.
- Changed exception type to IntegrityError for constraint violations as requested by Joseph Canedo.
- If scale and precision are not specified, an attempt is made to return a long integer as requested by Joseph Canedo.
- Added workaround for Oracle bug which returns an invalid handle when the prepare call fails. Thanks to firstname.lastname@example.org for providing the code that demonstrated the problem.
- The cursor method arrayvar() will now accept the actual list so that it is not necessary to call cursor.arrayvar() followed immediately by var.setvalue().
- Fixed bug where attempts to execute the statement “None” with bind variables would cause a segmentation fault.
- Added support for binding by position (paramstyle = “numeric”).
- Removed memory leak created by calls to OCIParamGet() which were not mirrored by calls to OCIDescriptorFree(). Thanks to Mihai Ibanescu for pointing this out and providing a patch.
- Added support for calling cursor.executemany() with statement None implying that the previously prepared statement ought to be executed. Thanks to Mihai Ibanescu for providing a patch.
- Added support for rebinding variables when a subsequent call to cursor.executemany() uses a different number of rows. Thanks to Mihai Ibanescu for supplying a patch.
- The microseconds are now displayed in datetime variables when nonzero similar to method used in the datetime module.
- Added support for binary_float and binary_double columns in Oracle 10g.
Version 4.0.1 (February 2004)¶
- Fixed bugs on 64-bit platforms that caused segmentation faults and bus errors in session pooling and determining the bind variables associated with a statement.
- Modified test suite so that 64-bit platforms are tested properly.
- Added missing commit statements in the test setup scripts. Thanks to Keith Lyon for pointing this out.
- Fix setup.py for Cygwin environments. Thanks to Doug Henderson for providing the necessary fix.
- Added support for compiling cx_Oracle without thread support. Thanks to Andre Reitz for pointing this out.
- Added support for a new keyword parameter called threaded on connections and session pools. This parameter defaults to False and indicates whether threaded mode ought to be used. It replaces the module level attribute OPT_Threading although examining the attribute will be retained until the next release at least.
- Added support for a new keyword parameter called twophase on connections. This parameter defaults to False and indicates whether support for two phase (distributed or global) transactions ought to be present. Note that support for distributed transactions is buggy when crossing major version boundaries (Oracle 8i to Oracle 9i for example).
- Ensure that the rowcount attribute is set properly when an exception is raised during execution. Thanks to Gary Aviv for pointing out this problem and its solution.
Version 4.0 (December 2003)¶
- Added support for subclassing connections, cursors and session pools. The changes involved made it necessary to drop support for Python 2.1 and earlier although a branch exists in CVS to allow for support of Python 2.1 and earlier if needed.
- Connections and session pools can now be created with keyword parameters, not just sequential parameters.
- Queries now return integers whenever possible and long integers if the number will overflow a simple integer. Floats are only returned when it is known that the number is a floating point number or the integer conversion fails.
- Added initial support for user callbacks on OCI functions. See the documentation for more details.
- Add support for retrieving the bind variable names associated with a cursor with a new method bindnames().
- Add support for temporary LOB variables. This means that setinputsizes() can be used with the values CLOB and BLOB to create these temporary LOB variables and allow for the equivalent of empty_clob() and empty_blob() since otherwise Oracle will treat empty strings as NULL values.
- Automatically switch to long strings when the data size exceeds the maximum string size that Oracle allows (4000 characters) and raise an error if an attempt is made to set a string variable to a size that it does not support. This avoids truncation errors as reported by Jon Franz.
- Add support for global (distributed) transactions and two phase commit.
- Force the NLS settings for the session so that test tables are populated correctly in all circumstances; problems were noted by Ralf Braun and Allan Poulsen.
- Display error messages using the environment handle when the error handle has not yet been created; this provides better error messages during this rather rare situation.
- Removed memory leak in callproc() that was reported by Todd Whiteman.
- Make consistent the calls to manipulate memory; otherwise segfaults can occur when the pymalloc option is used, as reported by Matt Hoskins.
- Force a rollback when a session is released back to the session pool. Apparently the connections are not as stateless as Oracle’s documentation suggests and this makes the logic consistent with normal connections.
- Removed module method attach(). This can be replaced with a call to Connection(handle=) if needed.
Version 3.1 (August 2003)¶
- Added support for connecting with SYSDBA and SYSOPER access which is needed for connecting as sys in Oracle 9i.
- Only check the dictionary size if the variable is not NULL; otherwise, an error takes place which is not caught or cleared; this eliminates a spurious “Objects/dictobject.c:1258: bad argument to internal function” in Python 2.3.
- Add support for session pooling. This is only support for Oracle 9i but is amazingly fast – about 100 times faster than connecting.
- Add support for statement caching when pooling sessions, this reduces the parse time considerably. Unfortunately, the Oracle OCI does not allow this to be easily turned on for normal sessions.
- Add method trim() on CLOB and BLOB variables for trimming the size.
- Add support for externally identified users; to use this feature leave the username and password fields empty when connecting.
- Add method cancel() on connection objects to cancel long running queries. Note that this only works on non-Windows platforms.
- Add method callfunc() on cursor objects to allow calling a function without using an anonymous PL/SQL block.
- Added documentation on objects that were not documented. At this point all objects, methods and constants in cx_Oracle have been documented.
- Added support for timestamp columns in Oracle 9i.
- Added module level method makedsn() which creates a data source name given the host, port and SID.
- Added constant “buildtime” which is the time when the module was built as an additional means of identifying the build that is in use.
- Binding a value that is incompatible to the previous value that was bound (data types do not match or array size is larger) will now result in a new bind taking place. This is more consistent with the DB API although it does imply a performance penalty when used.
Version 3.0a (June 2003)¶
- Fixed bug where zero length PL/SQL arrays were being mishandled
- Fixed support for the data type “float” in Oracle; added one to the display size to allow for the sign of the number, if necessary; changed the display size of unconstrained numbers to 127, which is the largest number that Oracle can handle
- Added support for retrieving the description of a bound cursor before fetching it
- Fixed a couple of build issues on Mac OS X, AIX and Solaris (64-bit)
- Modified documentation slightly based on comments from several people
- Included files in MANIFEST that are needed to generate the binaries
- Modified test suite to work within the test environment at Computronix as well as within the packages that are distributed
Version 3.0 (March 2003)¶
- Removed support for connection to Oracle7 databases; it is entirely possible that it will still work but I no longer have any way of testing and Oracle has dropped any meaningful support for Oracle7 anyway
- Fetching of strings is now done with predefined memory areas rather than dynamic memory areas; dynamic fetching of strings was causing problems with Oracle 9i in some instances and databases using a different character set other than US ASCII
- Fixed bug where segfault would occur if the ‘/’ character preceded the ‘@’ character in a connect string
- Added two new cursor methods var() and arrayvar() in order to eliminate the need for setinputsizes() when defining PL/SQL arrays and as a generic method of acquiring bind variables directly when needed
- Fixed support for binding cursors and added support for fetching cursors (these are known as ref cursors in PL/SQL).
- Eliminated discrepancy between the array size used internally and the array size specified by the interface user; this was done earlier to avoid bus errors on 64-bit platforms but another way has been found to get around that issue and a number of people were getting confused because of the discrepancy
- Added support for the attribute “connection” on cursors, an optional DB API extension
- Added support for passing a dictionary as the second parameter for the cursor.execute() method in order to comply with the DB API more closely; the method of passing parameters with keyword parameters is still supported and is in fact preferred
- Added support for the attribute “statement” on cursors which is a reference to the last SQL statement prepared or executed
- Added support for passing any sequence to callproc() rather than just lists as before
- Fixed bug where segfault would occur if the array size was changed after the cursor was executed but before it was fetched
- Ignore array size when performing executemany() and use the length of the list of parameters instead
- Rollback when connection is closed or destroyed to follow DB API rather than use the Oracle default (which is commit)
- Added check for array size too large causing an integer overflow
- Added support for iterators for Python 2.2 and above
- Added test suite based on PyUnitTest
- Added documentation in HTML format similar to the documentation for the core Python library
Version 2.5a (August 2002)¶
- Fix problem with Oracle 9i and retrieving strings; it seems that Oracle 9i uses the correct method for dynamic callback but Oracle 8i will not work with that method so an #ifdef was added to check for the existence of an Oracle 9i feature; thanks to Paul Denize for discovering this problem
Version 2.5 (July 2002)¶
- Added flag OPT_NoOracle7 which, if set, assumes that connections are being made to Oracle8 or higher databases; this allows for eliminating the overhead in performing this check at connect time
- Added flag OPT_NumbersAsStrings which, if set, returns all numbers as strings rather than integers or floats; this flag is used when defined variables are created (during select statements only)
- Added flag OPT_Threading which, if set, uses OCI threading mode; there is a significant performance degradation in this mode (about 15-20%) but it does allow threads to share connections (threadsafety level 2 according to the Python Database API 2.0); note that in order to support this, Oracle 8i or higher is now required
- Added Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS pairs where applicable to support threading during blocking OCI calls
- Added global method attach() to cx_Oracle to support attaching to an existing database handle (as provided by PowerBuilder, for example)
- Eliminated the cursor method fetchbinds() which was used for returning the list of bind variables after execution to get the values of out variables; the cursor method setinputsizes() was modified to return the list of bind variables and the cursor method execute() was modified to return the list of defined variables in the case of a select statement being executed; these variables have three methods available to them: getvalue([<pos>]) to get the value of a variable, setvalue(<pos>, <value>) to set its value and copy(<var>, <src_pos>, <targ_pos>) to copy the value from a variable in a more efficient manner than setvalue(getvalue())
- Implemented cursor method executemany() which expects a list of dictionaries for the parameters
- Implemented cursor method callproc()
- Added cursor method prepare() which parses (prepares) the statement for execution; subsequent execute() or executemany() calls can pass None as the statement which will imply use of the previously prepared statement; used for high performance only
- Added cursor method fetchraw() which will perform a raw fetch of the cursor returning the number of rows thus fetched; this is used to avoid the overhead of generating result sets; used for high performance only
- Added cursor method executemanyprepared() which is identical to the method executemany() except that it takes a single parameter which is the number of times to execute a previously prepared statement and it assumes that the bind variables already have their values set; used for high performance only
- Added support for rowid being returned in a select statement
- Added support for comparing dates returned by cx_Oracle
- Integrated patch from Andre Reitz to set the null ok flag in the description attribute of the cursor
- Integrated patch from Andre Reitz to setup.py to support compilation with Python 1.5
- Integrated patch from Benjamin Kearns to setup.py to support compilation on Cygwin
Version 2.4 (January 2002)¶
- String variables can now be made any length (previously restricted to the 64K limit imposed by Oracle for default binding); use the type cx_Oracle.LONG_STRING as the parameter to setinputsizes() for binding in string values larger than 4000 bytes.
- Raw and long raw columns are now supported; use the types cx_Oracle.BINARY and cx_Oracle.LONG_BINARY as the parameter to setinputsizes() for binding in values of these types.
- Functions DateFromTicks(), TimeFromTicks() and TimestampFromTicks() are now implemented.
- Function cursor.setoutputsize() implemented
- Added the ability to bind arrays as out parameters to procedures; use the format [cx_Oracle.<DataType>, <NumElems>] as the input to the function setinputsizes() for binding arrays
- Discovered from the Oracle 8.1.6 version of the documentation of the OCI libraries, that the size of the memory location required for the precision variable is larger than the printed documentation says; this was causing a problem with the code on the Sun platform.
- Now support building RPMs for Linux.
Version 2.3 (October 2001)¶
- Incremental performance enhancements (dealing with reusing cursors and bind handles)
- Ensured that arrays of integers with a single float in them are all treated as floats, as suggested by Martin Koch.
- Fixed code dealing with scale and precision for both defining a numeric variable and for providing the cursor description; this eliminates the problem of an underflow error (OCI-22054) when retrieving data with non-zero scale.
Version 2.2 (July 2001)¶
- Upgraded thread safety to level 1 (according to the Python DB API 2.0) as an internal project required the ability to share the module between threads.
- Added ability to bind ref cursors to PL/SQL blocks as requested by Brad Powell.
- Added function write(Value, [Offset]) to LOB variables as requested by Matthias Kirst.
- Procedure execute() on Cursor objects now permits a value None for the statement which means that the previously prepared statement will be executed and any input sizes set earlier will be retained. This was done to improve the performance of scripts that execute one statement many times.
- Modified module global constants BINARY and DATETIME to point to the external representations of those types so that the expression type(var) == cx_Oracle.DATETIME will work as expected.
- Added global constant version to provide means of determining the current version of the module.
- Modified error checking routine to distinguish between an Oracle error and invalid handles.
- Added error checking to avoid setting the value of a bind variable to a value that it cannot support and raised an exception to indicate this fact.
- Added extra compile arguments for the AIX platform as suggested by Jehwan Ryu.
- Added section to the README to indicate the method for a binary installation as suggested by Steve Holden.
- Added simple usage example as requested by many people.
- Added HISTORY file to the distribution.