We have neither log shipping nor database mirroring on our system, so the
only way I could experiment with a standby database was to restore a backup
to a new database, using the standby option. Is the database I created a hot
or a warm standby? Can both kinds be used as a read-only data source for
queries or reports?I'd call your implementation a warm standby.
Yes, you can query such a database restored using STANDBY.
As for LS and M:
For LS, you can query the db is you restore using STANDBY, but you have to kick out the users for
each new log restore. Not very practical.
For mirroring, you can create a database snapshot of the mirrored database and query that snapshot.
I do recommend that you evaluate your HS requirements and your scalability requirements separately
and then decide which technology is best suited for each (HA and scalability). It might happen that
the same technology is good for both, but it isn't uncommon to use different technologies for the
two.
--
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://sqlblog.com/blogs/tibor_karaszi
"Bev Kaufman" <BevKaufman@.discussions.microsoft.com> wrote in message
news:6F37569F-1767-4F58-B0AB-90EBB83620AE@.microsoft.com...
> We have neither log shipping nor database mirroring on our system, so the
> only way I could experiment with a standby database was to restore a backup
> to a new database, using the standby option. Is the database I created a hot
> or a warm standby? Can both kinds be used as a read-only data source for
> queries or reports?
>|||Generally:
They call "Hot standby" when there is automatic failover in the high
availbility system. (Like SQL Server Failover Clustering or Database
Mirroring with High Availibility mode)
"Warm standby" when you can failover manually. (Log Shipping and Database
Mirroring's High Performance and Protection modes etc.)
Attach\detach, backup\restore kind of stuff is called "Cold standby"
Also I wanted to add to Tibor's message that, you'll need Enterprise Edition
of SQL Server 2005 to be able to use Database Snapshot in your environment.
--
Ekrem Ã?nsoy
http://www.ekremonsoy.net , http://ekremonsoy.blogspot.com
MCBDA, MCITP:DBA, MCSD.Net, MCSE, MCBMSP, MCT
"Bev Kaufman" <BevKaufman@.discussions.microsoft.com> wrote in message
news:6F37569F-1767-4F58-B0AB-90EBB83620AE@.microsoft.com...
> We have neither log shipping nor database mirroring on our system, so the
> only way I could experiment with a standby database was to restore a
> backup
> to a new database, using the standby option. Is the database I created a
> hot
> or a warm standby? Can both kinds be used as a read-only data source for
> queries or reports?
>
Showing posts with label shipping. Show all posts
Showing posts with label shipping. Show all posts
Friday, February 24, 2012
Hot Standby/Warm Standby
Hi...can someone please explain the difference between a hot standby and
warm standby...and how replication is a hot standby and log shipping is a
warm standbyIn the way that these terms are generally used, a warm standby is a solution
where you can lose a number of modifications (transaction), where a hot
standby is where you don't lose any transactions at all. I'm talking about
committed transactions, btw. Log shipping is warm as you do the log backup
perhaps every 5 minutes, so you can lose 5 minutes worth of data. Cluster is
hot, as both nodes work against the same data. Replication is rather hot, as
the replication latency is in the vicinity of a few seconds.
--
Tibor Karaszi, SQL Server MVP
Archive at:
http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sqlserver
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
> Hi...can someone please explain the difference between a hot standby and
> warm standby...and how replication is a hot standby and log shipping is a
> warm standby
>|||This is a multi-part message in MIME format.
--=_NextPart_000_06CC_01C3AD24.2B5C8F20
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charset="Windows-1252"
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A hot standby will take over from the failed server automatically and in a
short time without human intervention. A clustered install of SQL Server is
an example of a hot standby.
A warm standby takes longer and does require human intervention. Both
methods you described are warm standby's. However, it can be debated as to
whether replication is a standby or not.
--
Tom
---
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Columnist, SQL Server Professional
Toronto, ON Canada
www.pinnaclepublishing.com/sql
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
Hi...can someone please explain the difference between a hot standby and
warm standby...and how replication is a hot standby and log shipping is a
warm standby
--=_NextPart_000_06CC_01C3AD24.2B5C8F20
Content-Type: text/html;
charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
&
A hot standby will take over from the =failed server automatically and in a short time without human =intervention. A clustered install of SQL Server is an example of a hot =standby.
A warm standby takes longer and does =require human intervention. Both methods you described are warm standby's. =However, it can be debated as to whether replication is a standby or not.
-- Tom
---T=homas A. Moreau, BSc, PhD, MCSE, MCDBASQL Server MVPColumnist, SQL =Server ProfessionalToronto, ON Canadahttp://www.pinnaclepublishing.com/sql">www.pinnaclepublishing.com=/sql
"Terry" wrote in message news:e4sKB1UrDHA.2584=@.TK2MSFTNGP09.phx.gbl...Hi...can someone please explain the difference between a hot standby andwarm standby...and how replication is a hot standby and log shipping is =awarm standby
--=_NextPart_000_06CC_01C3AD24.2B5C8F20--|||I might add that hardware level replications (not SQL replication) such as
EMC SRDF in the synchronous mode can also be considered as a hot standby
solution.
--
Linchi Shea
linchi_shea@.NOSPAMml.com
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
> Hi...can someone please explain the difference between a hot standby and
> warm standby...and how replication is a hot standby and log shipping is a
> warm standby
>
warm standby...and how replication is a hot standby and log shipping is a
warm standbyIn the way that these terms are generally used, a warm standby is a solution
where you can lose a number of modifications (transaction), where a hot
standby is where you don't lose any transactions at all. I'm talking about
committed transactions, btw. Log shipping is warm as you do the log backup
perhaps every 5 minutes, so you can lose 5 minutes worth of data. Cluster is
hot, as both nodes work against the same data. Replication is rather hot, as
the replication latency is in the vicinity of a few seconds.
--
Tibor Karaszi, SQL Server MVP
Archive at:
http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sqlserver
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
> Hi...can someone please explain the difference between a hot standby and
> warm standby...and how replication is a hot standby and log shipping is a
> warm standby
>|||This is a multi-part message in MIME format.
--=_NextPart_000_06CC_01C3AD24.2B5C8F20
Content-Type: text/plain;
charset="Windows-1252"
Content-Transfer-Encoding: 7bit
A hot standby will take over from the failed server automatically and in a
short time without human intervention. A clustered install of SQL Server is
an example of a hot standby.
A warm standby takes longer and does require human intervention. Both
methods you described are warm standby's. However, it can be debated as to
whether replication is a standby or not.
--
Tom
---
Thomas A. Moreau, BSc, PhD, MCSE, MCDBA
SQL Server MVP
Columnist, SQL Server Professional
Toronto, ON Canada
www.pinnaclepublishing.com/sql
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
Hi...can someone please explain the difference between a hot standby and
warm standby...and how replication is a hot standby and log shipping is a
warm standby
--=_NextPart_000_06CC_01C3AD24.2B5C8F20
Content-Type: text/html;
charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
&
A hot standby will take over from the =failed server automatically and in a short time without human =intervention. A clustered install of SQL Server is an example of a hot =standby.
A warm standby takes longer and does =require human intervention. Both methods you described are warm standby's. =However, it can be debated as to whether replication is a standby or not.
-- Tom
---T=homas A. Moreau, BSc, PhD, MCSE, MCDBASQL Server MVPColumnist, SQL =Server ProfessionalToronto, ON Canadahttp://www.pinnaclepublishing.com/sql">www.pinnaclepublishing.com=/sql
"Terry" wrote in message news:e4sKB1UrDHA.2584=@.TK2MSFTNGP09.phx.gbl...Hi...can someone please explain the difference between a hot standby andwarm standby...and how replication is a hot standby and log shipping is =awarm standby
--=_NextPart_000_06CC_01C3AD24.2B5C8F20--|||I might add that hardware level replications (not SQL replication) such as
EMC SRDF in the synchronous mode can also be considered as a hot standby
solution.
--
Linchi Shea
linchi_shea@.NOSPAMml.com
"Terry" <spankme@.nospam.com> wrote in message
news:e4sKB1UrDHA.2584@.TK2MSFTNGP09.phx.gbl...
> Hi...can someone please explain the difference between a hot standby and
> warm standby...and how replication is a hot standby and log shipping is a
> warm standby
>
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