I understand that this is very broad so let me give you the setting and be specific about my focus points.
Setting:
I am working with an existing PHP application using MYSQL. Tables almost all use the MYISAM engine and contain millions of rows for the most part. One of the largest tables uses an EAV design which is necessary but impacts on performance. The application was written to best leverage MYSQL cache. It requests a fair amount of requests per page load (partialy because of this) and is complex enough to have to go through most tables of the whole DB on each page load.
Pros:
Cons:
Feeling the need to scale up in the upcomming year, but not necessarily ready to pay for licensing right away, I've been thinking about rewriting the application and switching DBs.
The three options being considered are to either continue using mysql but with the INNODB engine, this way we can leverage more CPU power. Adapt to Oracle XE and get a license when we need to scale upwards of 4Gb database, 1Gb RAM or the 1 CPU limit (all of which we haven't hit yet). Or adapt to PostgreSQL
So the questions are :
I think that's already a lot to answer so I'll stop here. I don't mind simple/incomplete answers if there are links to compliment.
If you need any more information just let me know
Thanks in advance guys, the help is appreciated.
PostgreSQL supports full text search and indexes. Details here.
And it can use any number of CPU cores. It creates separate process for every session + some additional support processes. Details here.
PostgreSQL doesn't have built in query caching, but there are lots of open source utilities for this purpose.