Mysql and Flashback
Hello, We are planning on trying to do an Oracle to MySQL migration in the near future. The issue of a Mysql equivalent to Oracle's flashback was being discussed. After some digging it appears that there is no such feature in Mysql. One thought that I had was to do some intentional replication lag (say 12 to 24 hours)...that way if we needed to revert back we would have the option of doing so. Does anyone: a: know how to setup a replication to intentionally lag? b: know of a better way of engineering a flashback equivalent for Mysql? Thanks in advance, Shain -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Mysql and Flashback
Hi Shain, If you are using InnoDB its possible to patch to allow this functionality. Percona are in the early stages of developing a patch specifically to allow flashback type access to previous table states. https://bugs.launchpad.net/percona-patches/+bug/301925 If you wanted to go down the slave lag road, Maatkit has a tool for doing that. http://www.maatkit.org/doc/mk-slave-delay.html Cheers, Ewen On Tue, Nov 25, 2008 at 6:57 PM, Shain Miley [EMAIL PROTECTED] wrote: Hello, We are planning on trying to do an Oracle to MySQL migration in the near future. The issue of a Mysql equivalent to Oracle's flashback was being discussed. After some digging it appears that there is no such feature in Mysql. One thought that I had was to do some intentional replication lag (say 12 to 24 hours)...that way if we needed to revert back we would have the option of doing so. Does anyone: a: know how to setup a replication to intentionally lag? b: know of a better way of engineering a flashback equivalent for Mysql? Thanks in advance, Shain -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Mysql and Flashback
slave lag should be easy to do with a simple bash script. i.e. -
desired_delay=3600 # one hour lag
while sleep 60
do
behind=`mysql -u root --password=foobar -e show slave status\G |
grep 'Seconds_Behind_Master:' | awk '{ printf %s\n, $2 }'`
if [ $behind $desired_delay ]; then
mysql -u root --password=foobar -e slave stop
holdtime=`expr $desired_delay - $behind`
if [ $holdtime -gt 0]; then
mysql -u root --password=foobar -e slave stop
fi
else
mysql -u root --password=foobar -e slave start
fi
done
Not pretty, but should do the job with more sanity checks, with the
caveat that sometimes Seconds_Behind_Master can return some interesting
values
Howard Hart
Ooma, Inc.
ewen fortune wrote:
Hi Shain,
If you are using InnoDB its possible to patch to allow this functionality.
Percona are in the early stages of developing a patch specifically to
allow flashback type access to previous table states.
https://bugs.launchpad.net/percona-patches/+bug/301925
If you wanted to go down the slave lag road, Maatkit has a tool for doing that.
http://www.maatkit.org/doc/mk-slave-delay.html
Cheers,
Ewen
On Tue, Nov 25, 2008 at 6:57 PM, Shain Miley [EMAIL PROTECTED] wrote:
Hello,
We are planning on trying to do an Oracle to MySQL migration in the near
future. The issue of a Mysql equivalent to Oracle's flashback was being
discussed. After some digging it appears that there is no such feature in
Mysql. One thought that I had was to do some intentional replication lag
(say 12 to 24 hours)...that way if we needed to revert back we would have
the option of doing so.
Does anyone:
a: know how to setup a replication to intentionally lag?
b: know of a better way of engineering a flashback equivalent for Mysql?
Thanks in advance,
Shain
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For list archives: http://lists.mysql.com/mysql
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