匿名通过本文主要向大家介绍了dbcc checkdb,dbcc,dbcc checktable,dbcc dbreindex,dbcc shrinkfile等相关知识,希望本文的分享对您有所帮助
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下面这些dbcc command有些是没有官方支持的，不建议初学者使用。切记小心使用，不过有很多还是非常有用，有兴趣的可以测试看看！
Unauthorized
of Sybase DBCC Commands
Use them at your own risk!
dbcc allocdump ( dbid, page )
Displays all extents on an allocation page.
Parameters
dbid database ID
page allocation page number
dbcc allocmap ( dbid, one_all, allocpg, bit_stat )
Display or modify status of allocation bitmaps used to detect full allocation
pages.
Parameters
ParamDescriptionValid Values
dbid database ID
one_all bitmap(s) to check/modify 0 entire allocation map
1 single allocation map
allocpg allocation page, if one_all = 1
bit_stat status of the bits 0 check the status
1 set the bit(s)
2 clear the bit(s)
dbcc bhash ( print, bucket_limit )
Check integrity of and optionally print the buffer hash table.
Parameters
ParamDescriptionValid Values
print print option print_bufs display all buffers (default)
no_print display only buffers with problems
bucket_limit number of buffers allowed in a bucket. default = 0
dbcc bufcount ( n_chains )
Print up to 10 longest buffer chains and average chain length.
Parameters
ParamDescriptionValid Values
n_chains the number of chains to print 1-10
dbcc buffer ( [ dbid ][, objid ][, nbufs ], printopt, buftype )
Prints buffer headers and pages from the buffer cache.
Parameters
ParamDescriptionValid Values
dbid (optional) database name or database ID 0 will show data for all
databases.
objid (optional) object ID 0 will show data for all objects.
nbufs (optional) number of buffers to examine. If positive, the nbufs
buffers which meet the other criteria (dbid, objid) are printed in MRU to
LRU order. If negative, the last nbufs buffers which meet the criteria are
printed in LRU to MRU order. If 0, all buffers will be printed in MRU to
LRU order.
printopt print option 0 print out only the buffer header and page header
(default)
1 print out each row separately and the offset table
2 print out each row as a whole and the offset table
buftype buffer type to print Can be numeric or a symbolic character
string. See table below for possible strings and their hexadecimal
equivalents
Buffer Types
ParamHexDescription
BUF_DIRTY 1 Buffer in cache differs from disk image.
BUF_IO 2 Buffer is being read or written.
BUF_PINNED 4 The log must be written before this buffer is.
BUF_KEPT 8 Some process is using this buffer.
BUF_RLOCK 10 The buffer is resource locked.
BUF_TRIP 20 The buffer ages out of cache more slowly.
BUF_NEW 40 Buffer contains a new page and has never been written.
BUF_RWAIT 80 The process is waiting for rlock.
BUF_IOERR 100 There was an error writing tis buffer.
BUF_SPECIAL 200 If this buffer is written, update relevant descriptors.
BUF_WQUEUE 400 This buffer is queued for an out-of-sequence database dump.
BUF_NOTHASHED 800 This buffer is not hashed.
BUF_HASHED 1000 This buffer is hashed.
BUF_DIAG 2000 This is a special buffer used for diagnostics only.
BUF_FILTHY 4000 The buffer was dirtied while in I/O (log only).
BUF_NORELEASE 8000 This is used for coordinating releases of rlocks on
allocation pages.
dbcc bytes ( startaddress, length )
Dump out bytes from specific address.
Parameters
ParamDescription
startaddress starting address to dump
length number of bytes to dump
dbcc cacheremove ( dbname, objectname )
Removes object from cache.
Parameters
ParamDescription
dbname database name
objname object name
dbcc capture_tds (spid)
Captures Tabular Data Stream into a file called $SYBASE/install/TDSDUMP. File
contains full stream, including passwords -- chmod the file to protect this
information.
dbcc checkalloc [( dbname [, option ] )]
Check data and index pages against corresponding extent structures (earlier
newalloc).
Parameters
ParamDescriptionValid Values
dbname (optional) database name
option (optional) fix option fix report and fix descrepancies
nofix report decrepancies only (default)
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下面这些dbcc command有些是没有官方支持的，不建议初学者使用。切记小心使用，不过有很多还是非常有用，有兴趣的可以测试看看！
Unauthorized
of Sybase DBCC Commands
Use them at your own risk!
dbcc allocdump ( dbid, page )
Displays all extents on an allocation page.
Parameters
dbid database ID
page allocation page number
dbcc allocmap ( dbid, one_all, allocpg, bit_stat )
Display or modify status of allocation bitmaps used to detect full allocation
pages.
Parameters
ParamDescriptionValid Values
dbid database ID
one_all bitmap(s) to check/modify 0 entire allocation map
1 single allocation map
allocpg allocation page, if one_all = 1
bit_stat status of the bits 0 check the status
1 set the bit(s)
2 clear the bit(s)
dbcc bhash ( print, bucket_limit )
Check integrity of and optionally print the buffer hash table.
Parameters
ParamDescriptionValid Values
print print option print_bufs display all buffers (default)
no_print display only buffers with problems
bucket_limit number of buffers allowed in a bucket. default = 0
dbcc bufcount ( n_chains )
Print up to 10 longest buffer chains and average chain length.
Parameters
ParamDescriptionValid Values
n_chains the number of chains to print 1-10
dbcc buffer ( [ dbid ][, objid ][, nbufs ], printopt, buftype )
Prints buffer headers and pages from the buffer cache.
Parameters
ParamDescriptionValid Values
dbid (optional) database name or database ID 0 will show data for all
databases.
objid (optional) object ID 0 will show data for all objects.
nbufs (optional) number of buffers to examine. If positive, the nbufs
buffers which meet the other criteria (dbid, objid) are printed in MRU to
LRU order. If negative, the last nbufs buffers which meet the criteria are
printed in LRU to MRU order. If 0, all buffers will be printed in MRU to
LRU order.
printopt print option 0 print out only the buffer header and page header
(default)
1 print out each row separately and the offset table
2 print out each row as a whole and the offset table
buftype buffer type to print Can be numeric or a symbolic character
string. See table below for possible strings and their hexadecimal
equivalents
Buffer Types
ParamHexDescription
BUF_DIRTY 1 Buffer in cache differs from disk image.
BUF_IO 2 Buffer is being read or written.
BUF_PINNED 4 The log must be written before this buffer is.
BUF_KEPT 8 Some process is using this buffer.
BUF_RLOCK 10 The buffer is resource locked.
BUF_TRIP 20 The buffer ages out of cache more slowly.
BUF_NEW 40 Buffer contains a new page and has never been written.
BUF_RWAIT 80 The process is waiting for rlock.
BUF_IOERR 100 There was an error writing tis buffer.
BUF_SPECIAL 200 If this buffer is written, update relevant descriptors.
BUF_WQUEUE 400 This buffer is queued for an out-of-sequence database dump.
BUF_NOTHASHED 800 This buffer is not hashed.
BUF_HASHED 1000 This buffer is hashed.
BUF_DIAG 2000 This is a special buffer used for diagnostics only.
BUF_FILTHY 4000 The buffer was dirtied while in I/O (log only).
BUF_NORELEASE 8000 This is used for coordinating releases of rlocks on
allocation pages.
dbcc bytes ( startaddress, length )
Dump out bytes from specific address.
Parameters
ParamDescription
startaddress starting address to dump
length number of bytes to dump
dbcc cacheremove ( dbname, objectname )
Removes object from cache.
Parameters
ParamDescription
dbname database name
objname object name
dbcc capture_tds (spid)
Captures Tabular Data Stream into a file called $SYBASE/install/TDSDUMP. File
contains full stream, including passwords -- chmod the file to protect this
information.
dbcc checkalloc [( dbname [, option ] )]
Check data and index pages against corresponding extent structures (earlier
newalloc).
Parameters
ParamDescriptionValid Values
dbname (optional) database name
option (optional) fix option fix report and fix descrepancies
nofix report decrepancies only (default)
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