HowTo make Wiki history working with Postgres 9.0¶
When accessing the history version of a Wiki page (e.g. Wiki?version=16), just a string which is not human readable is displayed. It starts like this and is about 5000 characters long:
Same result for exporting TXT or HTML of the current version, and a Wiki-diff just diffs between two such strings.
PostgreSQL 9 introduced a new 'hex' format for bytea data input and output. Default for output is now hex, but it can be easily reverted to the old 'escape' format with the following command:
ALTER DATABASE redmine SET bytea_output TO 'escape';
See also #7677.