mxODBC Zope/Plone Database Adapter (2.0.0)

Introduction

The mxODBC Zope DA™ allows you to easily connect your Zope installation or Plone CMS to just about any database backend on the market today, giving you the reliability of the commercially supported eGenix.com product mxODBC and the flexibility of the ODBC standard as middle-tier architecture.

mxODBC Zope DA works on Windows, Linux, Mac OS X, Solaris and FreeBSD, providing you with the same interface, flexibility and robustness across all on all these platforms.

The mxODBC Zope DA implements thread-safe connection pooling and multiple physical connects per logical Zope connection. You can safely run Z SQL Methods in parallel, achieving a much better performance than other Zope database adapters under heavy load. This makes it ideal for deployment in ZEO Clusters and Zope hosting environments where stability and high performance are a top priority.

Using mxODBC Zope DA for Zope Database Applications

At EuroPython 2007, we have given a talk about Zope and relational database systems (RDBMS). The talk provides a high-level introduction on how Zope can be used for database web applications and where the mxODBC Zope DA can help. Please see our Presentations & Talks section for details.

Features

• Zope Level 3 Database Adapter: the mxODBC Zope DA is fully multi-threaded and can handle multiple connections to multiple databases.

• Fully compatible to standard Z SQL Methods.

• Connection Pooling: physical database connections are pooled and kept open, to reduce the connection overhead to a minimum. This is especially important for high latency database connections and ones like Oracle which take a considerable amount of time to setup

• Parallel Execution of Queries on a single logical connection: the mxODBC Zope DA can manage any number of physical connections on a single logical connection. This enables running truly parallel Z SQL Method queries -- a feature not available in other Zope DAs.

• Robust Mode of Operation: connections which have timed out or go away due to network problems are automatically reconnected.

• Cross-platform Connection Objects: The Zope DA will automatically choose the right platform specific ODBC manager for you.

• Per Connection Adjustable ODBC Interface: mxODBC comes with many different subpackages to choose from on Unix. The Zope DA allows you to select these subpackages on a per-connection basis.

• Per Connection Error Handling: you can tell each connection whether it should report ODBC warnings or not; furthermore all warnings and errors are made available as list .messages on the DatabaseConnection object.

• Transaction safe automatic reconnect: when the DA finds that a connection has timed out, it automatically tries a reconnect and replays the transaction on the connection (unlike other DAs which break the transaction scheme by doing a reconnect without replay).

• Built-in Schema Cache: this results in improved performance under heavy load.

• Database Schema Access: all ODBC catalog methods are made available for much better database schema inquiry. The catalog methods allow building generic database interrogation or manipulation tools and facilitates writing database independent Zope products.

• Lazy Connect: the mxODBC Zope DA only connects to the database backends when a connection is actually requested. This results in a better use of resources compared to other Zope DAs.

• Drop-in compatible to the ZODBC DA: the mxODBC Zope DA provides the same interfaces as the old and unmaintained ZODBC DA to allow a smooth upgrade path from this simplistic adapater to the high performance mxODBC Zope DA.

• Fully compatible to the popular Znolk SQL Wizard Product and other similar products relying on the common database schema access methods .tables() and .columns().

System Requirements

The mxODBC Zope DA distribution includes all software needed to connect Zope to an ODBC manager. However, it does not include an ODBC manager or any ODBC drivers. You have to have these installed in order to be able to use mxODBC Zope DA.

Windows:

On Windows, the situation is very simple: most databases come with ODBC drivers and register them with the Windows ODBC manager that's part of every Windows system.

Please consult the ODBC driver documentation for details on how to setup ODBC data sources. The mxODBC Zope DA Administration and User Manual also includes a section on this topic and some helpful hints in case you run into problems.

Linux, FreeBSD, Solaris, AIX:

On Unix, you will have to install one of the popular ODBC managers iODBC 3.52.x or unixODBC 2.2.x and then register the ODBC drivers for your database with these ODBC managers.

Linux systems usually come with at least one of these ODBC managers preinstalled. Please see the mxODBC Zope DA Administration and User Manual for setup instructions.

Mac OS X:

On Mac OS X, you can use the system system ODBC manager (which actually is a version of the popular iODBC manager).

Please see the mxODBC Zope DA Administration and User Manual for setup instructions.