From: Massimo Dal Zotto <dz@cs.unitn.it>

> tprintf.patch
>
>       tprintf.patch
>
>       adds functions and macros which implement a conditional trace package
>       with the ability to change flags and numeric options of running
>       backends at runtime.
>       Options/flags can be specified in the command line and/or read from
>       the file pg_options in the data directory.