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ski
Starting Member
3 Posts |
 Posted - 2010-06-22 : 08:19:05
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| Being a programmer with no database knowledge/experience, I am requesting answers to following questions as I am kind of stuck now: 1. I have a doubt regarding sql server 2005 (std edition, sync mode) mirroring. suppose if I have a database whose transaction log of 1 GB (due to some other reasons i have not taken tlog backup for months and we are not having periodical tlog backup scheduled, which we need to do soon anyway) and if I run some SQL updates of 200mb, will now JUST 200mb is going to be transferred to mirror or total of 1200 mb(1.2 GB) is going to be transferred to mirror? Ideally I suppose, only delta is going to transfer to mirror from principal. Or due to the fact we are not reducing tlog files is whole thing going to transfer to mirror hence performance of my database is going down day by day??2. And how large/huge transaction logs is going to effect db mirroring performance. my dba told, if we have smaller transaction logs then db mirroring will have good performance. How do we justify this?3. what's the best maintenance/backup plan for databases to give good performance while they are participating in mirroring. |
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ski
Starting Member
3 Posts |
Posted - 2010-06-22 : 09:42:08
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| If size of tlog does nt affect your db mirror slow performance so how can i debug to know which is causing my mirroring to give slow performance (as applications running are slow when mirroring is enabled and quite fast when we turn off mirroring...) |
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jen
Master Smack Fu Yak Hacker
4110 Posts |
Posted - 2010-08-18 : 06:18:10
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| afaik, if you have mirroring enabled, the trans logs will be backed up...so it will not grow due to infrequent backupsif the trans log backup becomes too big, the only issue is that it will take a bit longer to backup, quite a while to transfer it over to the server where the mirror database is, and restore will be a bit longer...this has no or minimal effect on the performance of the mirrored databaseslow performance, it may be traffic, network loadhere are some backup myths that might shed some light onto what backup and restores are doing...http://www.sqlskills.com/BLOGS/PAUL/post/A-SQL-Server-DBA-myth-a-day-%283030%29-backup-myths.aspx--------------------keeping it simple... |
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whats is exactly going to send to mirror from prin