Re: Backup and partitions

There is a very good document on Raid-5 written by Carey Millsap former VP and creator of Oracle's System Performance Group.

This document can be found at http://www.hotsos.com/catalog/level.html

Jonathan Lewis wrote:
>
> Howard,
>
> I have to disagree with the strength of your
> disapproval. It's only a million rows, and it's
> in a batch overnight. Hardware RAID-5 is often
> perfectly adequate for large data loads, and only
> on small fussy systems with lots of little writes
> is RAID-5 likely to be a real threat.
>
> The best reason for not using RAID-5 these days
> is that it isn't really much cheaper than a suitable
> RAID-10 configuration.
>
> Alex,
> As far as the partitioning goes, there are three main
> points to consider. First, partition the data according
> to the most frequent access pattern - if user wants
> a week (Mon-Sun) of data, partition into weeks, if they
> want the odd day, partition by day. 500 is getting a
> little near the borderline for partitioning, but is still
> okay if you don't have too many indexes.
>
> Second, make sure that all your indexes are local
> indexes, otherwise you lose the administrative
> benefits of partitioning.
>
> Third, the primary key of a partitioned table has to
> contain the partitioning columns if the corresponding
> index is to be locally partitioned.
>
> For backups - if you have partitioned by date, then build
> tablespaces per week or month. Then most of your old
> tablespaces can be read-only, and you need only back
> them up once after they have switched. From that point
> on, you can probably fit a hot backup of the rest of the
> database into the overnight batch, though, as Howard
> indicates, a cold backup would be nicer if you can do it -
> especially as your notes suggest that you could simply
> copy back the previous night's backup and reload the
> data in the event of a crash.
>
> --
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
> Publishers: Addison-Wesley
>
> Reviews at: http://www.jlcomp.demon.co.uk/book_rev.html
>
> Howard J. Rogers wrote in message
> <1NEi6.203$305.67479_at_inet16.us.oracle.com>...
> >
> >You are proposing to write 1,000,000 rows per night to a database using
> >RADI5? You *have* read all the RAID 5 arguments that gone through this
> >group over the past few months, have you?
> >
> >If you haven't, the short version goes like this: RAID 5 cripples systems
> >that need to write. Oracle warns you off using them. They are getting
> >better all the time, but nevertheless, there remains a significant write
> >penalty.
> >
 

> ><alex.berindei_at_elsag.it> wrote in message
> >news:96dqjd$pd2$1_at_news.netmar.com...
 

> >> I'm thinking to partition the table OPERATIONS by DATE, as rows inserted
 each
> >> night have all previous day. Problems here:
> >> - how big to make the partitions (week: 1Gb, month: 4Gb)?
> >> - is a good idea to partition also BOXES and, eventually, BIGBOXES
 tables?
> >> - there is a numerical column OPERATIONS.DIPENDENCY, range 1 to 1000,
 used
 in
> >> most selects from OPERAZIONE. An option could be to partition the table
 using
> >> two colums (DATE, DIPENDENCY), with larger ranges for DATE: (DATE 3
 mounts,
> >> DIPENDENCY: 10 ranges 1-100,101-200,...).
> >> This way I cand create local prefixed indexes in partitions, using colums
> >> (DATE, DIPENDENCY)
> >>
Received on Thu Feb 15 2001 - 17:17:29 CST