Hi Carl, Hope you are doing good ! Incase if systctl.conf file is not exist then in that case you need to create the file named /etc/sysctl.conf.
The recommended method for configuring shared memory in macOS is to create a file named /etc/sysctl.conf, containing variable assignments such as: kern.sysv.shmmax=4194304
kern.sysv.shmmin=1 kern.sysv.shmmni=32 kern.sysv.shmseg=8 kern.sysv.shmall=1024 You can check below link for more information about setting for MacOs, https://www.postgresql.org/docs/10/static/kernel-resources.html Also regarding your questions, >>> The question is do I need to change any settings to do with memory before I complete the reinstallation? A fresh postgres installation on a development/testing machine will probably be fine for most apps with default settings. However, when playing with big data, doing heavy aggregations as we do at adjust.io (even in development) can produce completely different performance than on a production server. Postgres comes with rather conservative/minimal defaults settings on your machine. If you want to get the most out of your local postgres on MacOS you need to tune your postgresql.conf, typically found at, /usr/local/var/postgres/postgresql.conf There are a lot of settings but here are a few of the most important: maintenance_work_mem effective_cache_size work_mem shared_buffers wal_buffers max_connections
Please check below link for more information,
https://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server >>> and do I need to worry about the second user account called PostgreSQL on my machine? PostgreSQL will create the default "Postgres" service account. As with any other server daemon that is accessible to the outside world, it is advisable to run PostgreSQL under a separate user account. This user account should only own the data that is managed by the server, and should not be shared with other daemons. (For example, using the user nobody is a bad idea.) It is not advisable to install executables owned by this user because compromised systems could then modify their own binaries.
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