|func||A function to evaluate||LazyExpr (required)|
|name||The global name of this cache (needed when more than one)||string|
|key||Cache key to use.||string (required)|
|period||The latest age of the cache.||int64|
Creates a cache object.
A Cache is a data structure which is used to speed up calculating data by keeping it’s value in memory. A cache is essentially a key value store - when the key is accessed, the function will be calculated producing a value. If the key is accessed again, the value is returned from the cache without calculating it again.
For example consider the following:
LET get_pid_query(Lpid) = SELECT Pid, Ppid, Name FROM pslist(pid=Lpid) SELECT cache(func=get_pid_query(Lpid=Pid), key=str(str=Pid)) FROM ....
The cache will ensure that get_pid_query() is only called once per unique Pid by comparing the key against the internal memory store.