Re: chicken and egg (now: backuping DBMSs)

[Stanislav Malyshev a.k.a Frodo]

EM>> Speaking about backuping, and also about databases like MySQL (in
EM>> another linux-il thread), let me ask you (you=linux-il subscribers)
EM>> to share your experience with backuping file-systems which include
EM>> running databases. I know that there are special backup methods for
EM>> databases. Do you use them?  Are there special backup tools (e.g.

As for MySQL, manual suggest doing mysqldump while read-locking the
database. I don't know any program that really does that - but you might
also stop DB server fro backup, backup files and start it again. It could
be done also by SQL means, but again - I know no program (except for
mysqldump itself) that does it.

EM>> BRU2000, etc.) which support databases and/or even know how to speak
EM>> with them so backups can be done during normal running of the
EM>> database?  And is there any way to backup databases incrementally?
EM>> Imagine a database of many megabytes, with some records modified
EM>> daily; It is not acceptable that the whole database should be copied
EM>> daily, and there must be a better way...

Well, I personally in such situations did the following - each table has a
timestamp field (let's call it "stamp"), and then you do, say, mysqldump
--when 'stamp > $last_backup', where $last_backup - timestamp of the last
backup. Recently, MySQL has also the thing called "update log" - if you
have backup of the DB from time T and update log from T up to now - you
can restore what it is now. The difference between two methods is extra
field in every table vs. extra space for update log and the first method
is table-local while the second is for entire DB server, AFAIK.

-- 
[EMAIL PROTECTED]      \/  There shall be counsels taken
Stanislav Malyshev      /\  Stronger than Morgul-spells
phone +972-3-9316425    /\              JRRT LotR.
http://sharat.co.il/frodo/      whois:!SM8333



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