Is it ok to have huge page life expectancy? Recently I have buffer issue for my SSIS package.
When i started to monitor metrics in perfmon i noticed the PLE is nearly 500000.
Is it ok to have this huge PLE.
Page Life Expectancy is simply how long (in seconds) a page will remain idle in the buffer before being removed to make room for another page.

There's no active harm in a very large PLE. It's possible that you've got more memory going to SQL Server than is absolutely required, but that's still not necessarily a bad thing.