You had brewed PostgreSQL and can’t get it to start after the Yosemite upgrade? Check the logs and see if you get the following error.

1

FATAL:  could not open directory "pg_tblspc": No such file or directory

If so, then you need to create a few directories that went missing as part of the upgrade.

1
2

cd /usr/local/var/postgres
mkdir pg_tblspc pg_twophase pg_stat_tmp

After running the above commands try starting PostgreSQL and it should start. Thanks to this Stack Overflow post for the details.