Feature request: Support tables with gaps in the primary key column 'id'

[glacier]

Tables that support deletions could have large gaps between ids and have large max id values, despite not having as many rows.

Lhm currently does not detect whether the block that it is copying is empty or not, which slows down the migration significantly because the delay is still incurred.

Just wondering if this feature is in the pipeline to be supported in the next release? I'm hoping to adopt lhm as a solution for large table migrations and it'll be awesome to have this feature.

Thanks

[nathwill]

@glacier we have the same issue due to large auto-increment settings; you can work around it by adjusting the stride size on the throttler, or using the slave-lag throttler