The Standard, Premium, and Enterprise plans are offered for production applications that require certain operating characteristics based on multitenancy architectures, CPU, RAM, and IO. These characteristics can be more easily understood with the help of the following table:

All plans run a 64-bit architecture, which ensures the best performance for the internal operations of Postgres. Heroku Postgres runs on a virtual infrastructure provided by Amazon AWS EC2.

The vCPU is the number of virtual processors in the instance and RAM is the amount of memory used to data cache. The PIOPs are a measure of how many IO disk operations can be performed per second.

For applications that require a lot of writes, IO can be a critical point. The data sets should fit in RAM, which ensures high performance with lower values of IOPs (Input/Output operations per second).

Finally, multitenancy refers to the principle of software architecture where a software instance is a server serving multiple client organizations (tenants).