The Totally Unauthorized List
of Sybase DBCC Commands



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)


dbcc checkcatalog [( dbname)]

Check consistency of system catalogs tables for database named.

Parameters
ParamDescription
dbname (optional) database name; default is current db


dbcc checkdb [( dbname [, skip_ncindex ] )]

Check consistency of data and index pages.

Parameters
ParamDescription
dbname (optional) database name; default is current db
skip_ncindex (optional) skip check on non clustered indexes for the database


dbcc checktable ( tabid [, skip_ncindex ] )

Check consistency of data and index pages.

Parameters
ParamDescription
tabid table name or table ID
skip_ncindex (optional) skip check on non clustered indexes for the table.


dbcc chgdbname ( dbname, newname )

Changes database name in DBINFO only.

Parameters
ParamDescription
dbname existing database name
newname new database name


dbcc chgobjname ( objname, newname )

Changes object name in cache only.

Parameters
ParamDescription
objname existing object name
newname new object name


dbcc cursorinfo ( cursor_level, cursor_name )

Displays cursor information.

Parameters
ParamDescription
cursor_level level number; -1 to get cursor info for all nesting levels
cursor_name name of the cursor


dbcc dbinfo [( dbname )]

Print DBINFO structure for specified database.

Parameters
ParamDescription
dbname (optional) database name


dbcc dbrecover ( dbname )

This will have recovery run on a suspect database without rebooting the server.

Parameters
ParamDescription
dbname database name


dbcc dbrepair ( db, option [, table][, index] )

Repair system tables.

Parameters
ParamDescriptionValid Values
db database ID or database name  
option repair option dropdb drop the specified database
findstranded display stranded objects
fixindex rebuild the specified index; used on system catalogs only
fixsysindex correct pfreeoff value for sysindexes
newthreshold rebuild the database threshold table
remap update the in-core image of the database usage map table
repairindex repair index for user tables
table (optional) table name  
index (optional) index ID  


dbcc dbtable ( dbid )

Print out the contents of the DBTABLE structure.

Parameters
ParamDescription
dbid database ID


dbcc delbuff ( dbid, page, dirty_flush, kept_flag, rlock_flag )

Remove buffer from cache, optionally flush to disk.

Parameters
ParamDescription
dbid database ID
page the logical page number of the page to be removed
dirty_flush if 1, then flush the page to disk if DIRTY
kept_flag if 1, then do not unkeep buffer if KEPT
rlock_flag if 1, then do not remove RESOURCE LOCK


dbcc delete_row ( dbid, page, delete_by_row, rownum )

Delete an index or data row by either a row number or an offset on a page.

Parameters
ParamDescriptionValid Values
dbid database ID  
page the logical page number  
delete_by_row delete location; by row or by offset 1 next parameter is interpreted as row number
0 next parameter is interpreted as offset on the page
rownum either a row number or offset  


dbcc des [( [ dbid ][, objid ] )]

Prints the contents of the specified DES (descriptor).

Parameters
ParamDescription
dbid (optional) database ID
objid (optional) object ID


dbcc descount ( n_chains )

Print up to 10 longest DES chains. P>
Parameters
ParamDescription
n_chains the number of chains to print, up to 10.


dbcc desdiag ( dbid, option )

Produce DES diagnostic reports.

Parameters
ParamDescriptionValid Values
dbid database ID 
optiondiagnostic to run -4 Display Hash Table Graph
-3 Display Diagnostic Maps
-2 Run all the tests (1-4)
-1 Return to caller - Exit
0 Redisplay this menu
1 Check Free Des Chain
2 Check Dbtable DES chain
3 Check Des Kept/Unkept chain
4 Check Des Name/Id hash table
5 Display 'lost' descriptors
6 Run tests (1-4), kepanic on errors


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