How to recover... deleted data without backups? Vedran Kesegić

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About me  M.Sc., FER, Zagreb, Croatia  HRPro  SQL Server Consultancy  Microsoft Certified Master: SQL 2008  Author: XDetails (SQL Management Studio)  Hobby: Photography

Tough situation?  Data is deleted or updated by mistake  DB is in SIMPLE recovery model  There are no backups! It is impossible to recover!... almost

3 Methods: 1.Good method 2.Bad method 3.Ugly method Not for faint-hearted!

A bit of theory... <60 sec

React FAST!  Clone the files (Why FULL backup is NOT enough?)  Put db OFFLINE  Copy files (both data and log)  Put db ONLINE  Relax  you bought time to recover the data  Needed by all 3 recovery methods!

Cloning the database (What is different from FULL backup?)

Recovery methods 1.Process Kill (sqlservr.exe)  Works if executed fast (before CHECKPOINT)  NOT recommended (violent, too short time) 2.Read „empty” part of transaction log  Undocumented commands and trace flags  Good, but not easy (will show in DEMO) 3.3rd party tools (ApexSQL log)  Easy  Costs money (well worth) ALL METHODS REQUIRE CLONING FIRST !!!

Extreme Recovery: Process Kill (Why it works? When it will not work?) DON’t DO IT!

Recovery by reading „empty” space of transaction log (reverse UPDATE and DELETE)

Recovery with 3rd party tool (ApexSQL Log)

Online options? Copy data and log files ONLINE?  SAN snapshots  VM snapshots (if running SQL in VM)  VSS (Volume Shadow Service)  Tools that use VSS (e.g. FreeFileSync)

Summary  CLONE files ASAP!  Relax  Use your favourite method!

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