[ale] OT - Postgresql Hot Spare time-lag config question

[wolf.halton at gmail.com (Wolf Halton)]

Well now I know why I can't remember us digging into this!!
It also explains why nobody is writing about a recipe offering more than
about a 10-second lag.
Thanks Jim, Geoffrey

On Mon, Dec 19, 2011 at 1:03 PM, Jim Kinney <jim.kinney at gmail.com> wrote:

> time lag on replication is considered bad and thus avoided like the plague.
>
> However, it can be done by a scripted write-ahead log migration so that
> only the logs from 30 minutes ago are processed.
>
> you might want to look at techniques for using WAL and roll back. The idea
> is the keep things as close to in-sync as possible but use the WALs to back
> out of a wrong commit.
>
> NOTE: by using atomic transactions you will not get corrupt data unless
> the logic flow around the insertion is bad. You can get incorrect data. As
> PostgreSQL performs extensive type-checking on inserts, the corrupt issue
> is moot. Unless all fields are text...
>
> On Mon, Dec 19, 2011 at 11:17 AM, Wolf Halton <wolf.halton at gmail.com>wrote:
>
>> A month ago I was talking to Jim Kinney about PostgreSQL replication, but
>> I can't remember if we got down to specifics of how to make PostgreSQL hot
>> spare take a 30-minute lag to its write.  The stuff I am seeing all looks
>> like the kind of feature most people are looking for is 1:1 realtime synced
>> hot-spare.  I want an offset so if the data is corrupt, it might be
>> possible to recover on main before the hot-spare data is also corrupt.
>>
>> I have been noodling around on the PostgreSQL site all morning and nobody
>> seems to have that piece there.
>>
>>
>>
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>
>
> --
> --
> James P. Kinney III
>
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