March 19, 2003 at 1:57 am
Hi all
Does anyone know of (or has info on) how I can retrieve the extent# and/or ID for a specific db file page. The DBCC PAGE command doesnt seem to help.
Cheers
Ck
Chris Kempster
www.chriskempster.com
Author of "SQL Server Backup, Recovery & Troubleshooting"
Author of "SQL Server 2k for the Oracle DBA"
March 19, 2003 at 7:14 am
DBCC IND doesn't seems to work either.
March 19, 2003 at 7:28 am
DBCC EXTENTINFO
ill see what this can do for me.
Chris Kempster
www.chriskempster.com
Author of "SQL Server Backup, Recovery & Troubleshooting"
Author of "SQL Server 2k for the Oracle DBA"
March 19, 2003 at 7:38 am
I didn't know this dbcc command. Can you post the parameters?
March 19, 2003 at 4:51 pm
From the http://www.transactsql.com site, great t-sql reference over the books online:
DBCC EXTENTINFO ('@dbname', '@tablename', @indid)
Example
--Display information about the extents in the authors table
--Clean up the display
SET NOCOUNT ON
--List information about the first index in the authors table
DBCC EXTENTINFO ('pubs', 'authors',1)
--List information about all the indexs in the authors table
DBCC EXTENTINFO ('pubs', 'authors')
--List information about all the indexs in the pubs database
DBCC EXTENTINFO ('pubs')
GO
This didnt do it for me, I believe the extent number must be embedded in the header pages that bitmap off the free and used extents, but even so, im still unsure how to extract this info. The command above is close to useless really in terms of extent numbering (logical or physical).
Chris Kempster
www.chriskempster.com
Author of "SQL Server Backup, Recovery & Troubleshooting"
Author of "SQL Server 2k for the Oracle DBA"
March 19, 2003 at 6:17 pm
Hi all
I believe the key is in dbcc page with the:
Allocation Status
-----------------
GAM (1:2) = ALLOCATED
GAM pages record what extents have been allocated. Each GAM covers 64,000 extents, or nearly 4 GB of data. The GAM has one bit for each extent in the interval it covers. If the bit is 1, the extent is free; if the bit is 0, the extent is allocated.
The key is clearly identifying the GAM page.
Chris Kempster
www.chriskempster.com
Author of "SQL Server Backup, Recovery & Troubleshooting"
Author of "SQL Server 2k for the Oracle DBA"
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