Checking Swap Space Size and Usage

step 1
grep SwapTotal /proc/meminfo

step 2
vmstat 3 100
  The fields si and so show the amount of memory paged in from disk and paged out to disk, respectively

step 3
ls -al /var/log/sa | grep "Oct 12"
sar -W -f /var/log/sa/sa12
The fields pswpin and pswpout show the total number of pages brought in and out per second, respectively.

alternative example for yesterday
sar -f /var/log/sa/sa$(date +%d -d yesterday)

solutions
Adding more RAM.
Reducing the size of the SGA.
Increasing the size of the swap space