Sou33 wrote:Just noticed that I was using PostgreSQL 9.3 all this years, upgrading to 12.0 might improve the performance I don't know.
There may be an improvement but it will not be a significant change.
Sou33 wrote:My 1st hardware has a sequential write speeds up to 520 MB/s , but the second hardware only 175 MBps . I guess there will be a massive performance drop right?
On a slower drive some reports will likely take longer to load for example although I can't quantify what the actual performance drop would be in your case.
Sou33 wrote:So is my only option to keep it on my C/ repertory and just purge a lot of hands to make some space?
I would not recommend purging anything especially if you don't have much free space. The purging itself may take some time as your database is large and after purging housekeeping will be required to update the database cache and reclaim the disk space that was used. These database operations require free space to run those functions optimally and you should ideally have at least as much free space on the disk as your database uses. If the housekeeping fails as a result then the database will not be in a good state and it will perform poorly. If you want a database with only recent data for example then it may be easier/faster to create a new database and import your most recent hands there.