Re: replication consistency checking

> Am 05.06.2015 um 16:56 schrieb Scott Ribe <scott_ribe@elevated-dev.com>:
>
>> On Jun 5, 2015, at 8:42 AM, Igor Neyman <ineyman@perceptron.com> wrote:
>>
>> The problem I see with “checksum utility” is that for it to work both compared servers should be “static”:  not
transactionswhile it does its job. 
>
> Indeed, and that was brought up before and OP seems to be ignoring it. What magic does MySQL (supposedly) use to
comparedatabases without interfering with updates? 
>
Also, if I remember the Postgres SR bug correctly, this kind of check that Percona provides would not have helped with
thiskind of bug. The corruption did not occur *during* replication but only if you restarted the slave because
transactionswere falsely marked as commited or non-commited when the slave came up again. You might have noticed the
corruptionearlier, though. 


> One could imagine a built-in feature in PG which depends on using MVCC and having both sides look at the same
snapshot.(Which would require repeatable reads.) 
I actually think this would a need thing to have (for pre-production) test environments, like alpha or beta testing.

Jan