[FEATURE] Cache index mapping and all related stuff in the plugin engine

[Yury-Fridlyand]

Is your feature request related to a problem?
SQL plugin queries index mapping every query executed.

What solution would you like?
Store index mapping, type environment, data types and all used things in memory. As a cache key index modification time could be used (if it is possible to retrieve it) or a checksum.
This will speed up consecutive execution of queries on the same indices.

What alternatives have you considered?
N/A

Do you have any additional context?
N/A

[acarbonetto]

Removing maintenance label. This is a feature/enhancement.