Re: Problem with Streaming Replication

On 06/30/2011 08:21 AM, abraao895 wrote:
> - The HD of the PC1(master) dead. The WAL file don't have replicated because
> it is a asynchronous proccess and suppose that this already didn't have
> happened.
>
> - The PC2(slave) doesn't have the last record.
>

That's exactly how some transaction loss can happen in this situation.
Some software worried about this problem maintains a small transaction
log outside of the database, so that it's possible to reconstruct really
critical information after such a disaster.

In PostgreSQL 9.1, due to be released later this year, synchronous
replication is available on a per-transaction basis.  That resolves the
concern you have--important transactions can be confirmed on one of the
slaves as a requirement before they commit.

--
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
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