We will have code along the lines of

opCtx->setCheckpointRead()
CheckpointLock lk = storageEngine->getCheckpointLock();
recordStore()->getCursor()
iam()->getCursor()

we need something in here to fail when the storage engine does not support background validation using checkpoints...

We were thinking of making RecoveryUnit::setTimestampReadSource check whether checkpoints are supported via a supportsCheckpoints() function on the RecoveryUnit or StorageEngine, but it appears setTimestampReadSource() is only implemented by WT and otherwise does nothing.

So, unless we can think of something else, we probably need to create a StorageEngine::supportsCheckpoints() function and use it at the cmd level.