How does cache work?

[david_vivathana]

I’m trying to understand datagroups/cache 

Say for example the max_cache_age is set to one hour and looker keeps rerunning the same query within the hour. what happens if the data is updated in the warehouse?

will the data be

1.stale up to one hour

or

2. updated and cached again

if number 2, I guess whats the point of setting up a max_cache_age in the first place? shouldn’t it be set to be cached as long as possible unless there's some sort of update to the underlying data?

Does cache also have an impact of storage?

[IanT]

Number 2.

think of it as a fallback, if you don’t want it just set it to a huge value.