Thread: Re: mirroring databases

Re: mirroring databases

From
"Henshall, Stuart - WCP"
Date:

Is rserv suitable for what you want?
I believe that provides single master async replication (not 100% sure as I havn't used it).
- Stuart

> -----Original Message-----
> From: April L [mailto:april@i-netco.com]
> Sent: 17 July 2002 18:30
> To: pgsql-novice@postgresql.org
> Subject: Re: [NOVICE] mirroring databases
>
>
> Thank you for that suggestion.
>
> What is the general method for replacing changed records and
> adding new
> records, between remote locations? Assume a one-way sync, ie a mirror.
> Records will only be added or changed at one location.
>
> Thank you,
>
> - April
>
>
> At 11:52 AM 7/17/2002 -0500, D. Duccini wrote:
> >
> >put a trigger on the table so that it updates a
> date/timestamp on updates,
> >like a "lastModified" column
> >
> >
> >On Wed, 17 Jul 2002, April L wrote:
> >
> >> Has anyone done, or know of utilities for, remote location
> "near real time
> >> mirroring" of postgres databases?
> >>
> >> An update every 15 minutes or so would work for this
> purpose. However, the
> >> total number of records is in the millions, and the number
> of changed or
> >> new records per day could be thousands.
> >>
> >> To avoid transferring all records, I'm imagining a flag column that
> >> indicates if a new or changed record has been transferred
> to the mirror
> yet.
> >>
> >> Any suggestions...?
> >>
> >> - April
> >>
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Re: mirroring databases

From
"Derek Barrett"
Date:
Here is the filesystem method using rsync.

I haven't used this method myself.

http://www.taygeta.com/ha-postgresql.html
----- Original Message -----
From: "D. Duccini" <duccini@backpack.com>
Date: Thu, 18 Jul 2002 15:03:14 -0500 (CDT)
To: April L <april@i-netco.com>
Subject: Re: [NOVICE] mirroring databases


>
> > What is the general method for replacing changed records and adding new
> > records, between remote locations? Assume a one-way sync, ie a mirror.
> > Records will only be added or changed at one location.
>
> make a 'diff' kind of file based on the changed information -- you can
> either send out the changes to a file to be processed remotely by a piece
> of software, or you can create a dump kind of file for direct import
>
> of course you could also look at doing a file-level replication using
> something like rsync
>
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> david@backpack.com            BackPack Software, Inc.        www.backpack.com
> +1 651.645.7550 voice       "Life is an Adventure.
> +1 651.645.9798 fax            Don't forget your BackPack!"
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Re: mirroring databases

From
April L
Date:
Interesting reading about rsync and heartbeat.

Now I understand the suggestion that I could dump the changed and new
records to a file, send them to the remote location perhaps with rsync,
then "import" them.

Luckily this is the novice list, so I can ask things like:

could I just do a select into (or whatever means "append new and replace
existing") statement at the remote location that accessed the changed/new
records at the other location? would that be a lot slower or have other
disadvantages?

Thank you,

- April

At 10:09 AM 7/19/2002 +0800, Derek Barrett wrote:
>Here is the filesystem method using rsync.
>
>I haven't used this method myself.
>
>http://www.taygeta.com/ha-postgresql.html
>----- Original Message -----
>From: "D. Duccini" <duccini@backpack.com>
>Date: Thu, 18 Jul 2002 15:03:14 -0500 (CDT)
>To: April L <april@i-netco.com>
>Subject: Re: [NOVICE] mirroring databases
>
>
>>
>> > What is the general method for replacing changed records and adding new
>> > records, between remote locations? Assume a one-way sync, ie a mirror.
>> > Records will only be added or changed at one location.
>>
>> make a 'diff' kind of file based on the changed information -- you can
>> either send out the changes to a file to be processed remotely by a piece
>> of software, or you can create a dump kind of file for direct import
>>
>> of course you could also look at doing a file-level replication using
>> something like rsync
>>
>>
-----------------------------------------------------------------------------
>> david@backpack.com            BackPack Software, Inc.
www.backpack.com
>> +1 651.645.7550 voice       "Life is an Adventure.
>> +1 651.645.9798 fax            Don't forget your BackPack!"
>>
-----------------------------------------------------------------------------
>>
>>
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>>
>
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