Cube.js: Feature request: metadata (age, cache hit/miss) of the results returned

[gane5h]

Is your feature request related to a problem? Please describe.
When a user loads a query, it isn't clear if these are fresh results, or from the cache preAggregated table. We need to display metadata on the results so that the user can make a decision to continue with the analysis or kick-start a refresh (outside the scope of this issue.)

Describe the solution you'd like
The load result should have metadata on the when the query was run, whether it came from a cache or preAggregation, etc.

Describe alternatives you've considered
No alternatives at the moment.

[paveltiunov]

@gane5h Hey Ganesh! Thanks for posting this! I think we can add something like loadTimestamp to the response. It'll be hard to say whether it comes from pre-aggregation or cache because it always comes from two of these sources. loadTimestamp will be always defined as min(cacheTimestamp, preAggregationTimestamp). Not sure if we need to provide two of these timestamps to client. Would love to hear your thoughts on this.

[gane5h]

Hey @paveltiunov – I think just one timesatmp loadTimestamp will be sufficient for display purposes. Thanks.

[paveltiunov]

Available as lastRefreshTime in load response.