Elaborate a way to calculate and present (show) Sizes on Ratel. | used space

[MichelDiz]

I was talking to Karandeep Singh in Slack, and I noticed there's this demand. He even talked to others and saw other people too.

Hence I remembered that tools like phpmyadmin have (as an example of an HTML viewer) a field that displays the size of the entire DB and tables. It would be interesting to have a set of space usage statistics. And each predicate also have its evaluation of space usage separate.

PS. Also taking into consideration Shards (if possible)

I know this would be technically complex to put in Ratel, but it's interesting.

[paulftw]

Closing as this is tracked in different jira cards now