An introduction to the ZODB

Laurence Rowe, Plone Conference 2007, Naples.laurence@lrowe.co.uk

In comparison to...

• Relational databases

• Hierarchical databases (LDAP, filesystems)

• Object-Relational Mappers (ORMs)

Transactions

• Concurrency Control

• Atomicity

• Conflict Errors

Scalability

• The Global Interpreter Lock

• ZEO

• Partitioning

ZEO

Storage 1

Storage 2

Zope

ZEO

Zope

Zope

Zope

ApachePound

(load balancer)

Storage types

• FileStorage

• DirectoryStorage

• PGStorage

Other features

• Savepoints

• Versions (deprecated)

• Undo

• BLOBs

• Packing

Best Practice

• Don’t read on write

• Keep your code on the filesystem

• BTrees

• Simple content types

Documentation

• http://wiki.zope.org/ZODB/Documentation