This is a fork of cx_oracle that adds a setting to enable LOB prefetching. If you're fetching a lot of LOB data this is a huge boon to performance.
Unfortunately I'm unable to sign Oracle's CLA, so this fork is the best I can do. If that changes in the future, these changes can be merged into the original codebase and this fork abandoned.
The branch with these changes is the default branch on this repo, yahoo-master. I'll try to ocassionally merge in changes from upstream as needed. Feel free to open an issue with any questions or issues.
See also github.com/jacobtolar/odpi for the required odpi changes.
cx_Oracle is a Python extension module that enables access to Oracle Database. It conforms to the Python database API 2.0 specification with a considerable number of additions and a couple of exclusions.
cx_Oracle is licensed under a [BSD license] which you can find here.
cx_Oracle 6 has been tested with Python version 2.7, and with versions 3.4 and higher. You can use cx_Oracle with Oracle 11.2, 12.1 and 12.2 client libraries, allowing connection to multiple Oracle Database versions. Oracle's standard client-server version interoperability allows connection to both older and newer databases, for example Oracle 12.2 client libraries can connect to Oracle Database 11.2 or later.
Issues and questions can be raised with the cx_Oracle community on GitHub or on the mailing list.
See the cx_Oracle Documentation and Release Notes.
See cx_Oracle Installation for detailed instructions.
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The simplest way to install cx_Oracle 6 RC2 is with pip:
python -m pip install cx_Oracle --preIf a binary wheel package is not available on PyPI for your platform, the source package will be used.
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After cx_Oracle is installed, Oracle client libraries must also be installed and configured. These can be from Oracle Instant Client, from a local Oracle Database, or from a full Oracle Client installation.
If you need the libraries, download and unzip the Oracle Instant Client 'Basic' package for your platform and set PATH, LD_LIBRARY_PATH, or similar platform-specific library path loading environment. See the installation notes for ODPI-C for help.
Versions 11.2, 12.1 and 12.2 of the Oracle Client libraries on Linux, Windows and macOS are supported. Users have also reported success with other platforms.
Note that if you download a source zip file directly from GitHub that you will also need to download an ODPI-C source zip file and extract it inside the directory called "odpi".
from __future__ import print_function # needed for Python 2.x
import cx_Oracle
# connect via SQL*Net string or by each segment in a separate argument
#connection = cx_Oracle.connect("user/password@TNS")
connection = cx_Oracle.connect("user", "password", "TNS")
cursor = connection.cursor()
cursor.execute("""
select Col1, Col2, Col3
from SomeTable
where Col4 = :arg_1
and Col5 between :arg_2 and :arg_3""",
arg_1 = "VALUE",
arg_2 = 5,
arg_3 = 15)
for column_1, column_2, column_3 in cursor:
print("Values:", column_1, column_2, column_3)For more examples, please see the test suite and the samples. You can also look at the scripts in the cx_OracleTools and the modules in the cx_PyOracleLib projects.
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Easily installed from PyPI.
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Support for Python 2 and 3.
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Support for Oracle Client 11.2, 12.1 and 12.2. Oracle's standard cross-version interoperability, allows easy upgrades and connectivity to different Oracle Database versions.
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Connect to Oracle Database 9.2, 10, 11 or 12 (depending on the Oracle Client version used).
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SQL and PL/SQL Execution, with full support for OCI features like statement caching and statement caching auto-tuning. Oracle OCI (which is the database access layer used by cx_Oracle) has significant optimizations, including compressed fetch, pre-fetching, client and server result set caching, and statement caching. cx_Oracle applications can additionally make full use of PL/SQL to keep business logic near the data in the database, where it can be processed without having to ship large volumes of data to the application.
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Full use of Oracle Network Service infrastructure, including encrypted network traffic and security features.
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Extensive Oracle data type support, including large object support (CLOB and BLOB).
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Direct binding to SQL objects. One great use case is binding Python objects to Oracle Spatial SDO objects.
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Array operations for efficient INSERT and UPDATEs.
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Array row counts and batch error handling for array operations.
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Fetching of large result sets.
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REF CURSOR support.
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Support for scrollable cursors. Go back and forth through your query results.
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Fetch PL/SQL Implicit Results. Easily return query results from PL/SQL.
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Row Prefetching. Efficient use of the network.
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Client Result Caching. Improve performance of frequently executed look-up statements.
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Support for Advanced Queuing. Use database notifications to build micro-service applications.
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Continuous Query Notification. Get notified when data changes.
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Support for Edition Based Redefinition. Easily switch applications to use updated PL/SQL logic.
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Support for setting application context during the creation of a connection, making application metadata more accessible to the database, including in LOGON triggers.
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End-to-end monitoring and tracing.
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Transaction Management.
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Session Pooling.
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Database Resident Connection Pooling (DRCP).
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Privileged Connections.
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External Authentication.
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Database startup and shutdown.
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Oracle Database High Availability Features, such as FAN notifications and Transaction Guard support.
DB API specification exclusions: The time data type is not
supported by Oracle and is therefore not implemented. The method
cursor.nextset() is not implemented either as the DB API specification assumes
an implementation of cursors that does not fit well with Oracle's implementation
of cursors and implicit results. See the method cursor.getimplicitresults()
for more information.