psycopg is a PostgreSQL database adapter for the Python programming language (just like pygresql and popy.) It was written from scratch with the aim of being very small and fast, and stable as a rock. The main advantages of psycopg are that it supports the full Python DBAPI-2.0 and being thread safe at level 2. ZPsycopgDA is a Zope Database Adapter based on psycopg and included in the psycopg package.

psycopg is different from the other database adapter because it was designed for heavily multi-threaded applications that create and destroy lots of cursors and make a conspicuous number of concurrent INSERTs or UPDATEs. Every open Python connection keeps a pool of real (UNIX or TCP/IP) connections to the database. Every time a new cursor is created, a new connection does not need to be opened; instead one of the unused connections from the pool is used. That makes psycopg very fast in tipical client-server applications that create a servicing thread every time a client request arrives.

Please note that this is not the official homepage for psycopg and that new versions are uploaded to Zope's site as a convenience for ZpsycopgDA (psycopg database adapter for Zope) users. The official home page for psycopg is on init.d web site.