Is your feature request related to a problem? Please describe.

A user requested the ability to map an array into fields where the arrays have some predefined set of values:

Sample Data: 
 - FOO: [{"key":"a", "val":2}, {"key":"b", "val":4}]
 - FOO: [{"key":"b", "val":3}]
 
Sample Output:

| a | b |
|---|---|
| 2 | 4 |
|nul| 3 |

Describe the solution you'd like

For an implementation of #126 (PostgreSQL driver with SKIP LOCKED), I create a SQL table for each consumer group containing the offsets ready to be consumed. The name for these tables is build by concatenating some prefix, the name of the topic and the name of the consumer group. In some of the test cases in the test suite, UUID are used for both, the topic and the consumer group. Each UUID has

我看到可以通过Prometheus搭建监控环境，如果有图文，更容易理解．