On Fri, 2022-10-28 at 10:14 +0000, PG Doc comments form wrote: > I remember in version 9 , to use variable you had to change in the > postgresql. > > Today it is easier , just use > > SET SESSION myprefix.myvariable = 'whatever' > > and all the transactions can use it , it is very useful in some cases, for > example to track the author of a change , you don't need to change all your > java/php/python code , just use a trigger on the table to fill up a column > "change_by" > > I've checked the documentation and that feature is not explained at all, not > even in the SET Command.
Most people consider this a kind of abuse of what is known as "placeholder parameters", documented in https://www.postgresql.org/docs/current/runtime-config-custom.html See for example https://postgr.es/m/2982579.1662416866%40sss.pgh.pa.us I believe it is a deliberate choice not to advertise that as "session variables", particularly since there is an improvement in the pipeline: https://commitfest.postgresql.org/40/1608/ Yours, Laurenz Albe
