The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/9.5/static/runtime-config-client.html
Description:
The section on temp_tablespaces is here:
https://www.postgresql.org/docs/9.5/static/runtime-config-client.html
I've tried setting temp_tablespaces with duplicate entries and have found
that it keeps those duplicates, making that entry used more frequently. This
is useful if the user wants to use one tablespace more frequently than
others. Example: "tablespace1, tablespace1, tablespace2" It'll pick
tablespace1 about 2X as often as tablespace2.
Support for duplicate values isn't explicitly mentioned in the
documentation, but I inferred it from the wording about the parameter being
a "list." But I had to go test to make sure it would work as I thought.