Trac Database Schema

The database schema is defined in trac.db_default​, along with the initial contents of the database. The schema includes the tables listed below.

Overview

Table Name	Purpose
attachment	Descriptions of attachments (the files themselves are stored on disk).
auth_cookie	User login cookies.
component	Values that can be used in a ticket's "component" field. The owner column is used as the default assignee for new tickets, if not overridden at the time of ticket submission.
enum	Maps integer IDs for issues' priorities, severities, etc. to human-readable names.
milestone	Project milestones.
node_change	1st half of the repository cache: for every changeset (as identified by the revision number), this table contains the nodes (i.e. files or directories) that have been added/modified/deleted.
permission	Username/action pairs describing who's allowed to do what. This table's contents also hold permission groups.
report	Stores the SQL to generate canned database reports.
revision	2nd half of the repository cache: changesets, containing the revision number, author, time, and log message. The list of files and directories modified by a changeset can be found by joining with node_change on the rev column.
session	Last user visit time.
session_attribute	Information about user settings, including name, email, and diff options.
system	System information such as the database version and repository cache metadata
ticket	Tickets.
ticket_change	Changes to tickets, on a field-by-field basis. The field value comment is special: it associates a comment with a set of field changes.
ticket_custom	The values of custom ticket fields.
version	As in component and milestone, this holds the options of the drop-down version list on the ticket form. Every version can have a time set, although that is not presently used other than for ordering the list of versions in the UI.
wiki	Wiki pages (including old revisions).

Database Schema

Note that some of the pictured relations are not "true" relations in the traditional relational meaning. Also, there's no "real" user table. The particular cases are explained in the embedded notes.

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See also: TracDev, TracDev/DatabaseUpgrades