What is SmartDiff in LiteSpeed for SQL Server? According to datasheet, it has better compression than LiteSpeed.
Is it a separate technology? If it is the same technology, how can it have better compression ratio and reduced backup time?
If there is already a backup strategy in place, eg. take a full backup on Sunday and differential backup for the rest of the week using LiteSpeed, will there still be significant savings when compared to SmartDiff?
From the Release Notes, SmartDiff is a wizard-oriented tool that allows the user to specify the conditions a differential or a full backup is triggered. The new wizard supports backup verification, file storage, scheduling, notification, and numerous other options.
It perfoms Full or Differential Backups based on user-defined conditions. Allowing scheduling and control whether a Full or a Differential is done based on percentage of data changed - let user set it and forget it.
It is LiteSpeeds ability to schedule a SmartDiff job which dynamically decides at execution time whether or not to run a full backup or a differential backup;based on avarious factors or thresholds that can be user-defined
1. How much data have changed since the last full backup
2. How many days have passed since the last full backup
SmartDiff uses a combination of Full and Differential backups. Combined, they can result in compression savings of another 60 to 85 percent over LiteSpeed and close to 95 percent over native full backup solutions.
Eg. The storage necessary to maintain 7 days worth of recoverability can reduce dramatically.
If the database is 100GB and changes 5% per day. Assuming 80% compression.
With just full backups:
Native:
Day 1: 100GB
Day 2: 100GB
Day 3: 100GB
Day 4: 100GB
Day 5: 100GB
Day 6: 100GB
Day 7: 100GB
Total: 700GB
Full Backups with LiteSpeed:
Day 1: 20GB
Day 2: 20GB
Day 3: 20GB
Day 4: 20GB
Day 5: 20GB
Day 6: 20GB
Day 7: 20GB
Total: 140GB
SmartDiff with LiteSpeed
Day 1: 20GB
Day 2: 1GB
Day 3: 2GB
Day 4: 3GB
Day 5: 4GB
Day 6: 5GB
Day 7: 6GB
Total: 41GB
Comparison:
Native:700GB
LiteSpeed Full: 140GB
SmartDiff: 41GB
As illustrated above, the savings are significant.
For the backup strategy in place,they are the same in savings. This isassumingall the validations of what SmartDiff does have been codedandalso assume that 7 days was going to be the best option for every backup set. But mostusers would notcode to that level and would nottrack the amount of data change to dynamically adjust the full backup interval. This iswhy most users do not usedifferentials and that is why SmartDiff is so compelling.
Datasheet - http://www.questsoftware.com.sg/Quest_Site_Assets/PDF/DSD-LiteSpeed4SQLServ-51-final_1.pdf
