How to set cluster level PostgreSQL config parameters?

[Question posted by a user on YugabyteDB Community Slack ]

This is done by using the ysql-pg-conf gflag in yb-tserver configuration: https://docs.yugabyte.com/latest/reference/configuration/yb-tserver/#ysql-pg-conf.

ysql_pg_conf takes a comma-separated list of tunables that would go in pg_conf in PostgreSQL.

An example command is if we want to set enable_hashagg=false:

./bin/yb-tserver [--master-addresses, --fs_data_dirs ...] --ysql_pg_conf="enable_hashagg=false"