-spec write(tab(), _Key, _Val) -> ok | {error, _}.
Update RAM representation of a record, write operation to WAL, sync WAL and then return.
Warning: this is a heavy operation. While this module batches writes, writes or deletes coming from a single process are always interleaved with a datasync.
If some process needs to reliably update a large number of records at once,
it’s better to use classy_table:atomically/2.