What is persist for in Looker?
persist_for lets you modify the amount of time that cached query results are used for a given Explore. The default cache length in Looker is 1 hour. Cache results are stored in an encrypted file on your Looker instance.
How do I filter data in Looker?
Click the Custom Filter checkbox in the upper right: Enter a dimension or function. Looker will display a list of functions, operators, and field names to use in your expression. Click on a term in the drop-down to add it to your expression.
How do I clear my Looker cache?
Click on the LookML button to open the LookML model file where the datagroup is defined. Select Reset Cache from the gear menu to immediately invalidate the cached results for all Explores using that datagroup.