We have tables with large amounts of data, when we imported into 11g about 20 million data records it started to perform very slowly.
For example
SELECT COUNT(*) FROM TABLE executed in about a minute.
I think we have problems with initial configutions and tune up, it is installed on Oracle Linux, server - XEON 4TB hardisk, 8 RAM and 4CPU. The database is not even using half of all resources, not using RAM and CPU. I am experienced in using MySql, and think 20 million records should not lock the database so much.
Now we are looking for good recommendations, guides or life hacks of performing with large data in 11g.
Which OS to use? Where to find good installation guide? Tune up tips.
Best regards.
Have you read the documentation? Oracle is considerably more sosphicated/complicated (take your pick) compared to MySQL. I'm afraid you can't just bung in on a machine and expect it to run performantly with large volumes of data.
There is a series of two-day guides designed to get new practitioners quickly up to speed. Here is the one for tuning. However it mainly focuses on the automatic tools for tuning Oracle, which incur additional license costs and which you probably don't have. So you should also have a look at the full Performance Guide. Find out more. Also check out Statspack which is free (and no longer mentioned in the more recent documentation). Find out more.
As for installation, there's a wealth of information. Find out more. You should pay particular attention to the Optimal Flexible Architecture (OFA), which is Oracle's recommended directory layout; the specifics will vary according to which OS you're using. Here's the one for Linux.