I migrate database links from Oracle to PostgreSQL using ora2pg?
2)How can I determine the appropriate RAM and CPU requirements for both the source and destination before performing an ora2pg migration? Specifically, is there a calculation method to determine the RAM and CPU based on the database size and application usage? For example, guidelines or formulas to determine the RAM and CPU requirements for databases ranging from 50 GB to 2 TB.
For the PostgreSQL configuration part, my blog post might be usable: https://proopensource.it/blog/postgresql-configuration But for detailed stuff more information would be needed, something where you might want to hire an expert. And you can't import database links. In PostgreSQL you need a foreign data wrapper to access external sources. These have to be installed. There is one available to access Oracle: oracle_fdw.
That's more up to metrics of the server under load. Even with huge databases but simple queries you can get along with a meager setup.
Is it depends on application usage?
No, database complexity. Simple database with easy queries and small joins will work fine even on 1Gb RAM. Add wider tables, multiple indexes, huge joins — everything will raise memory demand.
Обсуждают сегодня