DBCC EXTENTCHECK
This command has the same output as extentchain, and examines all extents on allocation pages for the specified object.
Syntax:
DBCC extentcheck(dbid, objid, indexid, sort = {1|0})
where:
dbid – database ID
objid – object ID
indexid – index ID
sort – state of the sort bit
(0 don’t report this, 1 report sort bit status)
Example:
DBCC TRACEON (3604)
DECLARE @dbid int, @objectid int
SELECT @dbid = DB_ID(‘pubs’)
SELECT @objectid = object_id(‘authors’)
DBCC EXTENTCHECK(@dbid,@objectid,0,1)
DBCC EXTENTDUMP
This command displays an extent dump.
Syntax:
DBCC extentdump(dbid, page)
where:
dbid – database ID
page – the number of the page controlled by the extent in question
Example:
DBCC TRACEON (3604)
DECLARE @dbid int
SELECT @dbid = DB_ID(‘pubs’)
DBCC EXTENTDUMP(@dbid, 1)
DBCC EXTENTZAP
This command can be used to clear all extents matching the parameter values.
Syntax:
DBCC extentzap(dbid, objid, indexid, sort)
where:
dbid – database ID
objid – object ID
indexid – index ID
sort – state of the sort bit
Example:
DBCC TRACEON (3604)
DECLARE @dbid int, @objectid int
SELECT @dbid = DB_ID(‘pubs’)
SELECT @objectid = object_id(‘authors’)
DBCC extentzap(@dbid,@objectid,0,0)
DBCC FINDNOTFULLEXTENTS
This command shows the extent id of extents allocated to the specified objid that are not full. If the objid is specified, then an indexid can be specified. If objid is all, then all database tables are displayed.
Syntax:
DBCC findnotfullextents(dbid, objid, indexid, sort = {1|0})
where:
dbid – database ID
objid – object ID
indexid – index ID
sort – state of the sort bit
Example:
DBCC TRACEON (3604)
DECLARE @dbid int, @objectid int
SELECT @dbid = DB_ID(‘pubs’)
SELECT @objectid = object_id(‘authors’)DBCC findnotfullextents(@dbid,@objectid,0,0)
DBCC HELP
DBCC HELP returns syntax information for the specified DBCC statement.
Syntax:
DBCC HELP (‘dbcc_statement’ | @dbcc_statement_var | ‘?’)
This is an example:
DBCC TRACEON (3604)
DECLARE @dbcc_stmt sysname
SELECT @dbcc_stmt = ‘CHECKTABLE’
DBCC HELP (@dbcc_stmt)