Module polkadot_node_core_approval_voting::approval_db

Approval DB accessors and writers for on-disk persisted approval storage data.

We persist data to disk although it is not intended to be used across runs of the program. This is because under medium to long periods of finality stalling, for whatever reason that may be, the amount of data we’d need to keep would be potentially too large for memory.

With tens or hundreds of parachains, hundreds of validators, and parablocks in every relay chain block, there can be a humongous amount of information to reference at any given time.

As such, we provide a function from this module to clear the database on start-up. In the future, we may use a temporary DB which doesn’t need to be wiped, but for the time being we share the same DB with the rest of Substrate.

Modules

• common
  Common helper functions for all versions of approval-voting database.
• v1
  Version 1 of the DB schema.
• v2
  Version 2 of the DB schema.
• v3
  Version 3 of the DB schema.