Analyzing physical RAM on the server to determine whether an increase needed

Check the total physical RAm on the server by running

lsattr -El sys0 -a realmem

Result would look something like this:

> lsattr -El sys0 -a realmem
realmem 25165824 Amount of usable physical memory in Kbytes False

The go through each end every database running on the server and do the following steps:

1. Login to sqlplus
2. Check MEMORY_TARGET parameter:

   SQL>SHOW PARAMETER MEMORY_TARGET
   

   If value is not 0, then use it, but if it is 0, then use sum of values of SGA and PGA

   SQL>SHOW PARAMETER SGA_TARGET
   

   and

   SQL>SHOW PARAMETER PGA_AGGREGATE_TARGET
   

3. After adding up all the values for each and every running database, calculate the percentage currently taken up. If it is no more than 50-70%, no change needed.