Compare with repair information in 6.x and 7.5.x
6.1 & 7.5
-----------
compare only
source side: lock table in exclusive mode, then get a snapshot, unlock
target side: lock table in exclusive mode, then get a snapshot, unlock
6.1 with repair option
---------------------------
first pass (compare)
source side: lock table in exclusive mode, then get a snapshot, unlock
target side: lock table in exclusive mode, then get a snapshot, unlock
second pass (repair)
source side: lock table in exclusive mode, then get a snapshot, unlock
target side: lock table in exclusive mode – the whole time while repairing.
7.5 with repair option
--------------------------
first pass (compare)
source side: get a snapshot – no lock at all.
target side: get a snapshot – no lock at all.
second pass (repair)
source side: lock table in exclusive mode, then get a snapshot, unlock
target side: lock table in exclusive mode – the whole time while repairing.
So, the difference between 6.1 and 7.5 is the compare phase with repair option.
7.5 does lock the tables in first pass; the second pass (repair phase) will filter
out any false oos rows from the first pass if any.
