mssqlserver.com: FAQ: Why is a SQL Server restore (LOAD DATABASE) so much slower than a dump database?
 


Search
  Home
  Articles
  Backup
  Books
  Certification
  FAQ
  Products
  Replication
  Scripts
  Seminars
  Training
  TSQL

MSDN Fourms
Philippine SSUG

  Resume

MHS Enterprises
FilAm Software
AcrylicAcetate.com
Bargain Humidors
Western Humidor



Why is a SQL Server restore (LOAD DATABASE) so much slower than a dump database?

The answer to this is that SQL initialises all pages during a load. So if you have 50Mb of data in a 5Gb database, the dump only processes the used 50Mb. But when the load occurs it loads the 50Mb of data - which takes roughly the same time as the dump - and then initialises the rest of the 4.95Gb of free space. This initialisation is done page by page and goes as fast as the disk subsystem will allow.

Michael R. Hotek

All content on this site, except where noted, represents an original work of Michael R. Hotek and is protected by applicable copyright laws. The SQL Server FAQ is the sole work of Neil Pike. No page, portion of a page, or download may be used for commercial purposes in whole or in part without the express, written permission of the applicable author.