/****************************************************************/ /* TRACE FLAGS IN SQL SERVER. */ /* By : Albert van der Sel */ /* Version: 0.1 */ /* Date : 10/04/2011 */ /****************************************************************/ ---------------------------------------------------------------------- Be SURE that you KNOW what the flag is for, that you are about to set. Always "crosscheck" a certain flag with google, or another search engine, or another source of information. ---------------------------------------------------------------------- There are 3 lists here. - The first list is often used in repairs (e.g. restore master, tempdb missing) - The second list is from MSDN. - The third list is compiled by me from various sources. LISTS OF TRACE FLAGS: ------------------ List 1: Repairs: ------------------ For some repairs, you might start sqlserver from the prompt, or the "net start" command, like: C:\> sqlservr.exe -m -f -T3608 where the "-T3608" is a "trace flage", and the "-m" is a startup parameter. Startup Parameters: -c Start as a console application from the prompt. -m Start the SQL service in single user mode. Only a single user can connect. command: sqlservr -m -f Start the SQL Server in minimal configuration mode. It's single user mode too. It may help if for example if severe memory constraints prohibit the service to start. -d master_file_path eg: -dE:\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\master.mdf -l master_log_path eg: -lE:\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\DATA\mastlog.ldf -e ERRORLOG_log_path eg: -eE:\Microsoft SQL Server\MSSQL11.MSSQLSERVER\MSSQL\Log\ERRORLOG -s Enables you to start a "named instance". Otherwise, the default Instance will start. eg: sqlservr.exe -c -s INSTNAME Remember to go to the "\mssql$Instance1\binn" directory. Trace flags: -T trace# Use this if you need to start SQL with a specific "Trace Flag". - Trace Flag 902: SQL server may not start after (un) install of updates. This trace flag will bypass internal upgrade scripts on startup after CU/SP install. - Trace Flag 3608: Only master database is recovered and opened, and all other databases are bypassed. However, some already running services like Reporting Service, might initiate that model and tempdb databases get started anyway. - Trace Flag 4022: Any of the automatically started procedures will be bypassed during startup. This could, for example, be a stored procedure. -Trace Flag 699: Use this with extreme care. It turns off transaction logging for the entire Instance. ------------------ List 2: from MSDN: ------------------ Trace flag no: Description 260 Prints versioning information about extended stored procedure dynamic-link libraries (DLLs). For more information about __GetXpVersion(), see Creating Extended Stored Procedures. Scope: global or session 1204 Returns the resources and types of locks participating in a deadlock and also the current command affected. Scope: global only 1211 Disables lock escalation based on memory pressure, or based on number of locks. The SQL Server Database Engine will not escalate row or page locks to table locks. Using this trace flag can generate excessive numbers of locks. This can slow the performance of the Database Engine, or cause 1204 errors (unable to allocate lock resource) because of insufficient memory. For more information, see Lock Escalation (Database Engine). If both trace flag 1211 and 1224 are set, 1211 takes precedence over 1224. However, because trace flag 1211 prevents escalation in every case, even under memory pressure, we recommend that you use 1224. This helps avoid "out-of-locks" errors when many locks are being used. Scope: global or session 1222 Returns the resources and types of locks that are participating in a deadlock and also the current command affected, in an XML format that does not comply with any XSD schema. Scope: global only 1224 Disables lock escalation based on the number of locks. However, memory pressure can still activate lock escalation. The Database Engine escalates row or page locks to table (or partition) locks if the amount of memory used by lock objects exceeds one of the following conditions: Forty percent of the memory that is used by Database Engine, exclusive of memory allocation using Address Windowing Extension (AWE). This is applicable only when the locks parameter of sp_configure is set to 0. Forty percent of the lock memory that is configured by using the locks parameter of sp_configure. For more information, see Setting Server Configuration Options. If both trace flag 1211 and 1224 are set, 1211 takes precedence over 1224. However, because trace flag 1211 prevents escalation in every case, even under memory pressure, we recommend that you use 1224. This helps avoid "out-of-locks" errors when many locks are being used. Note: Lock escalation to the table- or HoBT-level granularity can also be controlled by using the LOCK_ESCALATION option of the ALTER TABLE statement. Scope: global or session 2528 Disables parallel checking of objects by DBCC CHECKDB, DBCC CHECKFILEGROUP, and DBCC CHECKTABLE. By default, the degree of parallelism is automatically determined by the query processor. The maximum degree of parallelism is configured just like that of parallel queries. For more information, see max degree of parallelism Option. Parallel DBCC should typically be left enabled. For DBCC CHECKDB, the query processor reevaluates and automatically adjusts parallelism with each table or batch of tables checked. Sometimes, checking may start when the server is almost idle. An administrator who knows that the load will increase before checking is complete may want to manually decrease or disable parallelism. Disabling parallel checking of DBCC can cause DBCC to take much longer to complete and if DBCC is run with the TABLOCK feature enabled and parallelism set off, tables may be locked for longer periods of time. Scope: global or session 3205 By default, if a tape drive supports hardware compression, either the DUMP or BACKUP statement uses it. With this trace flag, you can disable hardware compression for tape drivers. This is useful when you want to exchange tapes with other sites or tape drives that do not support compression. Scope: global or session 3226 By default, every successful backup operation adds an entry in the SQL Server error log and in the system event log. If you create very frequent log backups, these success messages accumulate quickly, resulting in huge error logs in which finding other messages is problematic. With this trace flag, you can suppress these log entries. This is useful if you are running frequent log backups and if none of your scripts depend on those entries. 3608 Prevents SQL Server from automatically starting and recovering any database except the master database. Databases will be started and recovered when accessed. Some features, such as snapshot isolation and read committed snapshot, might not work. Use for Moving System Databases and Moving User Databases. Do not use during normal operation. 3625 Limits the amount of information returned in error messages. For more information, see Metadata Visibility Configuration. Scope: global only 4616 Makes server-level metadata visible to application roles. In SQL Server, an application role cannot access metadata outside its own database because application roles are not associated with a server-level principal. This is a change of behavior from earlier versions of SQL Server. Setting this global flag disables the new restrictions, and allows for application roles to access server-level metadata. Scope: global only 6527 Disables generation of a memory dump on the first occurrence of an out-of-memory exception in CLR integration. By default, SQL Server generates a small memory dump on the first occurrence of an out-of-memory exception in the CLR. The behavior of the trace flag is as follows: If this is used as a startup trace flag, a memory dump is never generated. However, a memory dump may be generated if other trace flags are used. If this trace flag is enabled on a running server, a memory dump will not be automatically generated from that point on. However, if a memory dump has already been generated due to an out-of-memory exception in the CLR, this trace flag will have no effect. Scope: global only 7806 Enables a dedicated administrator connection (DAC) on SQL Server Express. By default, no DAC resources are reserved on SQL Server Express. For more information, see Using a Dedicated Administrator Connection. List from other sources: ------------------ List 3: ------------------ NOTE: some of these are undocumented, could be removed in future flag Trace Flag Description -1 Sets trace flags for all connections. 105 SQL 6.5 - To over ride limitation of max 16 tables or sub queries allowed in a single select statement. 106 SQL 6.5/7 - Disables line number information for syntax errors. 107 SQL 6.5/7/8 - Interprets numbers with a decimal point as float instead of decimal. KB 203787 110 SQL 6.5 - Turns off ANSI select characteristics. KB 152032 168 SQL 9/10 - On querying through a view that uses the ORDER BY clause, the result are still returned in random order. KB 926292 204 SQL 6.5 - Backward compatibility switch that enables non-ansi standard behavior. E.g. previously SQL server ignored trailing blanks in the like statement and allowed queries that contained aggregated functions to have items in the group by clause that were not in the select list. 205 SQL 7/8 - Report when a statistics-dependent stored procedure is being recompiled as a result of AutoStat. KB 195565 206 SQL 6.5 - Provides backward compatibility for the set user statement. KB 160732 208 SET QUOTED IDENTIFIER ON. 210 SQL 9 - Error when you run a query against a view in SQL Server 2005: "An error occurred while executing batch". KB 945892 212 SQL 9 - Query may run much slower when compared to SQL 8 when you use a cursor to run the query. KB 951184 237 Tells SQL Server to use correlated sub-queries in Non-ANSI standard backward compatibility mode. 242 Provides backward compatibility for correlated subqueries where non-ANSI-standard results are desired. 243 243 Provides backward compatibility for nullability behavior. When set, SQL Server has the same nullability violation behavior as that of a ver 4.2: - Processing of the entire batch is terminated if the nullability error (inserting NULL into a NOT NULL field) can be detected at compile time. - Processing of offending row is skipped, but the command continues if the nullability violation is detected at run time. Behavior of SQL Server is now more consistent because nullability checks are made at run time and a nullability violation results in the command terminating and the batch or transaction process continuing. 244 Disables checking for allowed interim constraint violations. By default, SQL Server checks for and allows interim constraint violations. An interim constraint violation is caused by a change that removes the violation such that the constraint is met, all within a single statement and transaction. SQL Server checks for interim constraint violations for self-referencing DELETE statements, INSERT, and multi-row UPDATE statements. This checking requires more work tables. With this trace flag you can disallow interim constraint violations, thus requiring fewer work tables. 246 Derived or NULL columns must be explicitly named in a select...INTO or create view statement when not done they raise an error. This flag avoids that. 253 Prevents ad-hoc query plans to stay in cache. 257 Will invoke a print algorithm on the XML output before returning it to make the XML result more readable. 260 Prints versioning information about extended stored procedure dynamic-link libraries (DLLs). For more information about __GetXpVersion(), see Creating Extended Stored Procedures. Scope: global or session. 262 SQL 7 - Trailing spaces are no longer truncated from literal strings in CASE statements. KB 891116 302 Should be used with 310 to show the actual join ordering. Prints information about whether the statistics page is used, the actual selectivity (if available), and what SQL Server estimated the physical and logical I/O would be for the indexes. 310 Prints information about join order. Index selection information is also available in a more readable format using SET SHOWPLAN_ALL, as described in the SET statement. 320 Disables join-order heuristics used in ANSI joins. To see join-order heuristics use flag 310. SQL Server uses join-order heuristics to reduce the no' of permutations when using the best join order. 323 SQL 6.5 - Reports on the use of update statements using UPDATE in place. Shows a detailed description of the various update methods used. 325 Prints information about the cost of using a non-clustered index or a sort to process an ORDER BY clause. 326 Prints information about estimated & actual costs of sorts. Instructs server to use arithmetic averaging when calculating density instead of a geometric weighted average when updating statistics. Useful for building better stats when an index has skew on the leading column. Use only for updating the stats of a table/index with known skewed data. 330 Enables full output when using the SET SHOWPLAN_ALL option, which gives detailed information about joins. 342 Disables the costing of pseudo-merge joins, thus significantly reducing time spent on the parse for certain types of large, multi-table joins. One can also use SET FORCEPLAN ON to disable the costing of pseudo-merge joins because the query is forced to use the order specified in the FROM clause. 345 Increase the accuracy of choice of optimum order when you join 6 or more tables. 506 Enforces SQL-92 standards regarding null values for comparisons between variables and parameters. Any comparison of variables and parameters that contain a NULL always results in a NULL. 610 SQL 10 - Enable the potential for minimal-logging when: - Bulk loading into an empty clustered index, with no nonclustered indexes - Bulk loading into a non-empty heap, with no nonclustered indexes 611 SQL 9 - When turned on, each lock escalation is recorded in the error log along with the SQL Server handle number. 652 Disables read ahead for the server. 653 Disables read ahead for the current connection. 661 Disables the ghost record removal process. A ghost record is the result of a delete operation. When you delete a record, the deleted record is kept as a ghost record. Later, the deleted record is purged by the ghost record removal process. When you disable this process, the deleted record is not purged. Therefore, the space that the deleted record consumes is not freed. This behavior affects space consumption and the performance of scan operations. SCOPE: Global. If you turn off this trace flag, the ghost record removal process works correctly. 698 SQL 9 - Performance of INSERT operations against a table with an identity column may be slow when compared to SQL 8. KB 940545 699 Turn off transaction logging for the entire SQL dataserver. 806 Cause 'DBCC-style' page auditing to be performed whenever a database page is read into the buffer pool. This is useful to catch cases where pages are being corrupted in memory and then written out to disk with a new page checksum. When they're read back in the checksum will look correct, but the page is corrupt (because of the previous memory corruption). This page auditing goes someway to catching this - especially on non-Enterprise Edition systems that don't have the 'checksum sniffer'. 809 SQL 8 - Limits the amount of Lazy Write activity. 815 SQL 8/9 - Enables latch enforcement. SQL Server 8 (with service pack 4) and SQL Server 9 can perform latch enforcement for data pages found in the buffer pool cache. Latch enforcement changes the virtual memory protection state while database page status changes from "clean" to "dirty" ("dirty" means modified through INSERT, UPDATE or DELETE operation). If an attempt is made to modify a data page while latch enforcement is set, it causes an exception and creates a mini-dump in SQL Server installation's LOG directory. Microsoft support can examine the contents of such mini-dump to determine the cause of the exception. In order to modify the data page the connection must first acquire a modification latch. Once the data modification latch is acquired the page protection is changed to read-write. Once the modification latch is released the page protection changes back to read-only. 818 SQL 8 - Enables in memory ring buffer used to track last 2048 successful write operations. 830 SQL 9 - Disable the reporting of CPU Drift errors in the SQL Server errorlog like SQL Server has encountered 2 occurrence(s) of I/O requests taking longer than 15 seconds to complete. 834 SQL 8 - Causes SQL Server to use Windows large-page allocations for the memory that is allocated for the buffer pool. The page size varies depending on the hardware platform, but the page size may be from 2 MB to 16 MB. Large pages are allocated at startup and are kept throughout the lifetime of the process. 834 improves performance by increasing the efficiency of the translation look-aside buffer (TLB) in the CPU. Flag 834 applies only to 64-bit versions of SQL Server. You must have the Lock pages in memory user right to turn on trace flag 834. You can turn on trace flag 834 only at startup. Trace flag 834 may prevent the server from starting if memory is fragmented and if large pages cannot be allocated. Therefore, trace flag 834 is best suited for servers that are dedicated to SQL Server. Details - http://msdn2.microsoft.com/en-us/library/aa366720.aspx 835 SQL 9 / 10 - For 64 bit SQL Server. This turns off Lock pages in memory. 836 Causes SQL Server to size the buffer pool at startup based on the value of the max server mem option instead of based on the total physical memory. You can use trace flag 836 to reduce the number of buffer descriptors that are allocated at startup in 32-bit Address Windowing Extensions (AWE) mode. Applies only to 32-bit ver that have the AWE allocation enabled. Scope Startup Only. 845 SQL 9 / 10 - On 64 bit SQL Server non ENT. This turns on Lock pages in memory. Startup only KB 970070. 1106 SQL 9 - Used space in tempdb increases continuously when you run a query that creates internal objects in tempdb. KB 947204. 1117 Grows all data files at once, else it goes in turns. 1118 Switches allocations in tempDB from 1pg at a time (for first 8 pages) to one extent. There is now a cache of temp tables. When a new temp table is created on a cold system it uses the same mechanism as for SQL 8. When it is dropped though, instead of all the pages being deallocated completely, one IAM page & one data page are left allocated, then the temp table is put into a special cache. Subsequent temp table creations will look in the cache to see if they can just grab a pre-created temp table. If so, this avoids accessing the allocation bitmaps completely. The temp table cache isn't huge (32 tables), but this can still lead to a big drop in latch contention in tempdb. http://www.sqlskills.com/BLOGS/PAUL/post/Misconceptions-around-TF-1118.aspx 1180 SQL 7 - Forces allocation to use free pages for text or image data and maintain efficiency of storage. 1197 applies only in the case of SQL 7 - SP3. Helpful in case when DBCC SHRINKFILE and SHRINKDATABASE commands may not work because of sparsely populated text, ntext, or image columns 1197 1200 Prints lock information (the process ID and type of lock requested). 1202 Insert blocked lock requests into syslocks. 1204 Returns resources and types of locks participating in a deadlock and command affected. Scope: global only 1205 More detailed information about the command being executed at the time of a deadlock. Documented in SQL 7 BOL. 1206 Used to complement flag 1204 by displaying other locks held by deadlock parties. 1211 Disables lock escalation based on memory pressure, or based on number of locks. The SQL Server Database Engine will not escalate row or page locks to table locks. Using this trace flag can generate excessive numbers of locks. This can slow the performance of the Database Engine, or cause 1204 errors (unable to allocate lock resource) because of insufficient memory. For more information, see Lock Escalation (Database Engine). If both trace flag 1211 and 1224 are set, 1211 takes precedence over 1224. However, because trace flag 1211 prevents escalation in every case, even under memory pressure, we recommend that you use 1224. This helps avoid "out-of-locks" errors when many locks are being used. Scope: global or session 1216 SQL 7 - Disables Health reporting. Lock monitor when detects a (worker thread) resource level blocking scenario. If a SPID that owns a lock is currently queued to the scheduler, because all the assigned worker threads have been created and all the assigned worker threads are in an un-resolvable wait state, the following error message is written to the SQL Server error log: Error 1223: Process ID %d:%d cannot acquire lock "%s" on resource %s because a potential deadlock exists on Scheduler %d for the resource. Process ID %d:% d holds a lock "%h" on this resource. 1222 Returns the resources and types of locks that are participating in a deadlock and also the current command affected, in an XML format that does not comply with any XSD schema. Scope: global 1224 Disables lock escalation based on the number of locks. However, memory pressure can still activate lock escalation. The Database Engine escalates row or page locks to table (or partition) locks if the amount of memory used by lock objects exceeds one of the following conditions: - 40% of the memory that is used by Db Engine, exclusive of memory allocation using Address Windowing Extension (AWE). This is applicable when the locks parameter of sp_configure is set to 0. - Forty percent of the lock memory that is configured by using the locks parameter of sp_configure. If both trace flag 1211 and 1224 are set, 1211 takes precedence over 1224. However, because trace flag 1211 prevents escalation in every case, even under memory pressure, we recommend that you use 1224. This helps avoid "out-of-locks" errors when many locks are being used. Note: Lock escalation to the table- or HoBT-level granularity can also be controlled by using the LOCK_ESCALATION option of the ALTER TABLE statement. Scope: global or session 1261 SQL 8 - Disables Health reporting. Lock monitor when detects a (worker thread) resource level blocking scenario. If a SPID that owns a lock is currently queued to the scheduler, because all the assigned worker threads have been created and all the assigned worker threads are in an un-resolvable wait state, the following error message is written to the SQL Server error log: Error 1229: Process ID XXX owns resources that are blocking processes on scheduler XXX. 1400 Enables creation of database mirroring endpoint, which is required for setting up and using database mirroring. Scope - Startup 1448 SQL 9/10 - Changes in the publisher database are not replicated to the subscribers in a transactional replication if the publisher database runs exposed in a database mirroring session. On enabling 1448 on publisher instance. Log Reader Agent will always copy transactions that are marked for replication from transaction log into distribution database. Scope - GLOBAL. KB 937041 1462 SQL 10 - Turns off log stream compression and effectively reverts the behavior back to ver 9. 1603 Use standard disk I/O (i.e. turn off asynchronous I/O). 1609 Turns on the unpacking and checking of remote procedure call (RPC) information in Open Data Services. Used only when applications depend on the old behavior. 1610 Boot the SQL dataserver with TCP_NODELAY enabled. 1611 If possible, pin shared memory -- check errorlog for success/failure. 1613 Set affinity of the SQL data server engine's onto particular CPUs -- usually pins engine 0 to processor 0, engine 1 to processor 1. 1704 Prints information when a temporary table is created or dropped 1717 Causes new objects being created to be system objects. 1802 SQL 9 - After detaching a database that resides on network-attached storage, you cannot reattach the SQL Server database. Scope STARTUP. KB 922804 1806 Disables instant file initialization. 1807 SQL 9/10 - Allows creating a database file on a mapped or UNC network location. Not required with SQL 2008 R2. 1903 SQL 8 - When you capture a SQL Profiler trace in a file and then you try to import the trace files into tables by using the fn_trace_gettable function no rows may be returned. KB 911678 1905 2301 Enables advanced optimizations that are specific to decision support queries. This option applies to decision support processing of large data sets. 2328 SQL 9+ - Makes cardinality estimates upon resulting selectivity. The reasoning for this is that one or more of the constants may be statement parameters, which would change from one execution of the statement to the next. 2330 Stops the collection of statistics for sys.db_index_usage_stats. 2340 SQL 9/10 - Query processor may introduce a sort operation for optimization, though not required where the particular plan only touches a smaller number of rows. Setup cost for the sort operation may outweigh its benefits thus resulting in poor performance. KB 2009160 2382 SQL 8 - Statistics collected for system tables. 2389 SQL 9 - Tracks nature of columns by subsequent statistics updates. When SQL Server determines that the statistics increase three times, the column is branded ascending. The statistics will be updated automatically at query compile. 2390 Does the same like 2389 even if ascending nature of the column is not known and -- never enable without 2389. 2440 SQL 10 - Parallel query execution strategy on partitioned tables. SQL 9 used single thread per partition parallel query execution strategy. In SQL 10, multiple threads can be allocated to a single partition by turning on this flag. 2505 SQL 7 - Prevents DBCC TRACEON 208, SPID 10 errors from appearing in the error log. KB 243352 2508 Disables parallel non-clustered index checking for DBCC CHECKTABLE. 2509 Used with DBCC CHECKTABLE to see the total count of forward records in a table 2514 Used with DBCC CHECKTABLE to see the total count of ghost records in a table 2520 Force DBCC HELP to return syntax of undocumented DBCC statements. If 2520 is not turned on, DBCC HELP will refuse to give you the syntax stating: "No help available for DBCC statement 'undocumented statement'". 2521 SQL 7 SP2 - Facilitates capturing a Sqlservr.exe user-mode crash dump for postmortem analysis. 2528 SQL 8+ Disables parallel checking of objects by DBCC CHECKDB, CHECKFILEGROUP and CHECKTABLE. By default, the degree of parallelism is automatically determined by the query processor. The maximum degree of parallelism is configured just like that of parallel queries. For more information, see max degree of parallelism Option. Parallel DBCC should typically be left enabled. For DBCC CHECKDB, the query processor reevaluates and automatically adjusts parallelism with each table or batch of tables checked. Sometimes, checking may start when the server is almost idle. An administrator who knows that the load will increase before checking is complete may want to manually decrease or disable parallelism. Disabling parallel checking of DBCC can cause it to take much longer to complete and if DBCC is run with the TABLOCK feature enabled and parallelism set off, tables may be locked for longer periods of time. http://msdn.microsoft.com/en-us/library/ms176064.aspx Scope: global or session 2537 SQL 9/10 - Allows function ::fn_dblog to look inside all logs (not just the active log). 2542 SQL 8 - Used with Sqldumper.exe to get certain dumps. In range 254x - 255x. 2551 SQL 9 - Adds additional information to the dump file. 2566 SQL 9 - DBCC CHECKDB takes longer to run on an x64-based computer compared to a 32-bit computer. Kb - 945770 2701 SQL 6.5 - Sets the @@ERROR system function to 50000 for RAISERROR messages with severity levels of 10 or less. When disabled, sets the @@ERROR system function to 0 for RAISERROR messages with severity levels of 10 or less. 2861 SQL 8 - Cache query plans for queries that have a cost of zero or near to zero. When turned on, fn_get_sql function can return the SQL text for activities that have zero cost plans kb 325607 3001 Stops sending backup entries into MSDB. 3004 Shows information about backups and file creations use with 3005 to direct to error log. http://blogs.msdn.com/b/psssql/archive/2008/01/23/how-it-works-what-is-restore-backup-doing.aspx http://blogs.msdn.com/b/sql_pfe_blog/archive/2009/12/23/how-and-why-to-enable-instant-file-initialization.aspx 3005 Redirects output from 3004 to the error log. 3014 Provides more information related backups / file streams. http://blogs.msdn.com/b/psssql/archive/2008/02/06/how-it-works-how-does-sql-server-backup-and-restore-select-transfer-sizes.aspx 3028 3031 SQL 9 - Will turn the NO_LOG and TRUNCATE_ONLY options into checkpoints in all recovery modes. 3104 Causes SQL Server to bypass checking for free space. 3111 Cause LogMgr::ValidateBackedupBlock to be skipped during backup and restore operations. 3205 If a tape drive supports hardware compression, either the DUMP or BACKUP statement uses it. With this trace flag, you can disable hardware compression for tape drivers. This is useful when you want to exchange tapes with other sites or tape drives that do not support compression. Scope: global or session 3213 Trace SQL Server activity during backup process so that we will come to know which part of backup process is taking more time. 3222 Disables the read ahead that is used by the recovery operation during roll forward operations. 3226 With this trace flag, you can suppress BACKUP COMPLETED log entries going to WIN and SQL logs. 3228 3231 SQL 8/9 - Will turn the NO_LOG and TRUNCATE_ONLY options into no-ops in FULL/BULK_LOGGED recovery mode, and will clear the log in SIMPLE recovery mode. 3282 SQL 6.5 - Used after backup restoration fails. KB Q215458 3422 Cause auditing of transaction log records as they're read (during transaction rollback or log recovery). This is useful because there is no equivalent to page checksums for transaction log records and so no way to detect whether log records are being corrupted e careful with these trace flags - I don't recommend using them unless you are experiencing corruptions that you can't diagnose. Turning them on will cause a big CPU hit because of the extra auditing that's happening. 3502 Tracks CHECKPOINT - Prints a message to the log at the start and end of each checkpoint. 3503 Indicates whether the checkpoint at the end of automatic recovery was skipped for a database (this applies only to read-only databases). 3504 For internal testing. Will raise a bogus log-out-of-space condition from checkpoint() 3505 Disables automatic checkpoints. May increase recovery time and can prevent log space reuse until the next checkpoint is issued. Make sure to issue manual checkpoints on all read/write databases at appropriate time intervals. Note does not prevent the internal checkpoints that are issued by certain commands, such as BACKUP. 3601 Stack trace when error raised. Also see 3603 3602 Records all error and warning messages sent to the client. 3603 SQL Server fails to install on tricore, Bypass SMT check is enabled, flags are added via registry. Also see 3601. 3604 Sends trace output to the client. Used only when setting trace flags with DBCC TRACEON and DBCC TRACEOFF. 3605 Sends trace output to the error log. (if SQL Server is started from CMD output also appears on the screen) 3607 Skips the recovery of databases on the startup of SQL Server and clears the TempDB. Setting this flag lets you get past certain crashes, but there is a chance that some data will be lost 3608 Prevents Instance from automatically starting-recovering any database except master. Databases will be started and recovered when accessed. Some features, such as snapshot isolation and read committed snapshot, might not work. 3609 Skips the creation of the tempdb database at startup. Use this trace flag if the device or devices on which tempdb resides are problematic or problems exist in the model database. 3610 SQL 9 - Divide by zero to result in NULL instead of error. 3625 Limits the amount of information returned in error messages. For more information, see Metadata Visibility Configuration. Scope: global only 3626 Turns on tracking of the CPU data for the sysprocesses table. 3635 Print diagnostic information. Trace Flag 3635 Diagnostics are written to the console that started it. There are not written to the errorlog, even if 3605 is turned on. 3640 Eliminates sending DONE_IN_PROC messages to client for each statement in stored procedure. This is similar to the session setting of SET NOCOUNT ON, but when set as a trace flag, every client session is handled this way. 3654 3659 3689 Logs extended errors to errorlog when network disconnect occurs, turned off by default. Will dump out the socket error code this can sometimes give you a clue as to the root cause. 3913 SQL 7/8 - SQL Server does not update the rowcnt column of the sysindexes system table until the transaction is committed. When turned on the optimizer gets row count information from in-memory metadata that is saved to sysindexes system table when the transaction commits. 4001 Very verbose logging of each login attempt to the error log. Includes tons of information. 4010 4013 Writes an entry to error log when a new connection is established. For each connection that occurs, the trace flag writes two entries that look like: Login: sa saSQL Query Analyzer(local)ODBCmaster, server process ID (SPID): 57, kernel process ID (KPID): 57. Login: sa XANADUsaSQL Query Analyzer(local)ODBCmaster, server process ID (SPID): 57, kernel process ID (KPID): 57. 4020 Boot without recover. 4022 When turned, automatically started procedures are bypassed. 4029 Logs extended errors to errorlog when network disconnect occurs, turned off by default. Will dump out the socket error code this can sometimes give you a clue as to the root cause. 4030 Prints both a byte and ASCII representation of the receive buffer. Used when you want to see what queries a client is sending to SQL Server. You can use this trace flag if you experience a protection violation and want to determine which statement caused it. Typically, you can set this flag globally or use SQL Server Enterprise Manager. You can also use DBCC INPUTBUFFER. 4031 Prints both a byte and ASCII representation of the send buffers (what SQL Server sends back to the client). You can also use DBCC OUTPUTBUFFER. 4032 Traces the SQL commands coming in from the client. The output destination of the trace flag is controlled with the 3605/3604 trace flags. 4044 SA account can be unlocked by rebooting server with trace flag. If sa (or sso_role) password is lost, add this to your RUN_serverfile. This will generate new password when server started. 4052 SQL 9+ Prints TDS packets sent to the client (output) to console.- Startup only. 4055 SQL 9+ Prints TDS packets received from the client to console.- Startup only. 4102 SQL 9 - Query performance is slow if the execution plan of the query contains semi join operators Typically, semi join operators are generated when the query contains the IN keyword or the EXISTS keyword. Enable flag 4102 and 4118 to overcome this. KB - 940128 4104 SQL 9 - Overestimating cardinality of JOIN operator. When additional join predicates are involved, this problem may increase the estimated cost of the JOIN operator to the point where the query optimizer chooses a different join order. When the query optimizer chooses a different join order, SQL 9 system performance may be slow. KB - 920346 4107 SQL 9 - When you run a query that references a partitioned table, query performance may decrease. KB 923849 4116 SQL 9 - Query runs slowly when using joins between a local and a remote table. KB 950880 4117 SQL 9 - Blocking issues occur when updating rows in a table. KB 948445 4118 SQL 9 - Query performance is slow if the execution plan of the query contains semi join operators Typically, semi join operators are generated when the query contains the IN keyword or the EXISTS keyword. Enable flag 4102 and 4118 to overcome this. KB 940128 4101 SQL 9 - Query that involves an outer join operation runs very slowly. However, if you use the FORCE ORDER query hint in the query, the query runs much faster. Additionally, the execution plan of the query contains the following text in the Warnings column: NO JOIN PREDICATE. 4121 4125 SQL 9 - Query may take more time to finish if using an inner join to join a derived table that uses DISTINCT keyword. KB 949854 4127 SQL 9 - Compilation time of some queries is very long in an x64-based version. Basically its more than execution time because more memory allocations are necessary in the compilation process. Kb 953569 4133 SQL 9/10 - Size of error log file grows very quickly when query notifications are created and destroyed in a high ratio. KB 958006 4135 SQL 10 - Disables optimization in Query optimizer KB 960770 4606 Over comes SA password by startup. KB 936892 4612 Disable the ring buffer logging - no new entries will be made into the ring buffer. 4613 Generate a minidump file whenever an entry is logged into the ring buffer. 4616 Makes server-level metadata visible to application roles. In SQL Server, an application role cannot access metadata outside its own database because application roles are not associated with a server-level principal. This is a change of behavior from earlier versions of SQL Server. Setting this global flag disables the new restrictions, and allows for application roles to access server-level metadata. Scope: global 4618 Limits number of entries per user cache store. It may incur a small CPU overhead as when removing old cache entries when new entries are inserted. It performs this action to limit the size of the cache store growth. However, the CPU overhead is spread over time. Kb 933564 5101 Forces all I/O requests to go through engine 0. This removes the contention between processors but could create a bottleneck if engine 0 becomes busy with non-I/O tasks. 5102 Prevents engine 0 from running any non-affinitied tasks. 5302 Alters default behavior of select...INTO (and other processes) that lock system tables for the duration of the transaction. This trace flag disables such locking during an implicit transaction. 6527 Disables generation of a memory dump on the first occurrence of an out-of-memory exception in CLR integration. By default, SQL Server generates a small memory dump on the first occurrence of an out-of-memory exception in the CLR. Scope: global The behavior of the trace flag is as follows: - If this is used as a startup trace flag, a memory dump is never generated. However, a memory dump may be generated if other trace flags are used. - If this trace flag is enabled on a running server, a memory dump will not be automatically generated from that point on. However, if a memory dump has already been generated due to an out-of-memory exception in the CLR, this trace flag will have no effect. 7103 Disable table lock promotion for text columns. KB 230044 7300 Retrieves extended information about any error you encounter when you execute a distributed query. 7501 Dynamic cursors are used by default on forward-only cursors. Dynamic cursors are faster than in earlier versions and no longer require unique indexes. 75401 4disables dynamic cursor enhancements and reverts to version 6.0 behavior. 7502 Disables the caching of cursor plans for extended stored procedures. 7505 Enables version 6.x handling of return codes when calling dbcursorfetchex and the resulting cursor position follows the end of the cursor result set. 7525 SQL 8 - Reverts to ver 7 behavior of closing nonstatic cursors regardless of the SET CURSOR_CLOSE_ON_COMMIT state. 7601 7603 7604 7605 Helps in gathering more information in full text search, Turns on full text tracing. Gather more information about full text search (indexing process to the error log.) 7613 SQL 9 - Search results are missing when performing a full-text search operation on Win SharePoint Services 2.0 site after upgrading. KB 927643 7614 SQL 9 - Full-text index population for the indexed view is very slow. KB 928537 7646 SQL 10 - Avoids blocking when using full text indexing. An issue we experienced that full text can be slow when there is a high number of updates to the index and is caused by blocking on the docidfilter internal table. 7806 SQL 9 - Enables a dedicated administrator connection (DAC) on SQL Svr Express. By default, no DAC resources are reserved on SQL Express. 8002 Allows changing the meaning of affinity mask so that it is treated like a process affinity. KB 818769 8004 SQL server to create a mini-dump once you enable 2551 and a out of memory condition is hit. 8011 Disables the collection of additional diagnostic information for Resource Monitor. You can use the information in this ring buffer to diagnose out-of-memory conditions. Scope: GLOBAL. 8012 Records an event in the schedule ring buffer every time that one of the following events occurs: - A scheduler switches context to another worker. - A worker is suspended or resumed. - A worker enters the preemptive mode or the non-preemptive mode. You can use the diagnostic information in this ring buffer to analyze scheduling problems. For example, you can use the information in this ring buffer to troubleshoot problems when SQL Server stops responding. Trace flag 8012 disables recording of events for schedulers. Startup Only. 8015 SQL 9 - CPU utilization of a CPU in a single node increases to 100 percent when you use SQL Server 2005 on a multiprocessor computer that uses NUMA architecture. - Startup KB 948450 8017 8018 Disables the creation of the ring buffer, and no exception information is recorded. The exception ring buffer records the last 256 exceptions that are raised on a node. Each record contains some information about the error and contains a stack trace. A record is added to the ring buffer when an exception is raised. 8019 Disables stack collection during the record creation, has no effect if trace flag 8018 is turned on. Disabling the exception ring buffer makes it more difficult to diagnose problems that are related to internal server errors. You can turn on trace flag 8018 and trace flag 8019 only at startup. 8020 SQL Server uses the size of the working set when SQL Server interprets the global memory state signals from the operating system. Trace flag 8020 removes the size of the working set from consideration when SQL Server interprets the global memory state signals. If you use this trace flag incorrectly, heavy paging occurs, and the performance is poor. Therefore, contact Microsoft Support before you use. You can turn on trace flag 8020 only at startup 8030 SQL 9 - Occurs only on 64-bit servers with 16+ (GB) of physical memory. When you run a query in SQL 9 after the instamce was operational for some time, the query performance may be slow. Additionally, when you query the sys.dm_os_wait_stats dynamic management view, you may notice that there are many rows in which the values of the wait_type column are SOS_RESERVEDMEMBLOCKLIST or DBCC MEMORYSTATUS. This situation indicates that many multipage allocations exist. KB 917035 8033 SQL 9 - Disable the reporting of CPU Drift errors in the SQL Server errorlog like time stamp counter of CPU on scheduler id 1 is not synchronized with other CPUs. 8038 SQL 9+ Database engine & SSRS use SQLOS which exposes an internal timer which if set to a 1ms granularity, more power consumption may occur on Windows client. 8038 avoids it affecting the output of some DMV's. Scope Startup only KB 972767 8049 SQL 9+ Startup only - Allows use of 1ms times even when patched. Check 8038 for details. KB 972767 8202 Used to replicate UPDATE as DELETE/INSERT pair at the publisher. i.e. UPDATE commands at the publisher can be run as an "on-page DELETE/INSERT" or a "full DELETE/INSERT". If the UPDATE command is run as an "on-page DELETE/INSERT," the Logreader send UDPATE command to the subscriber, If the UPDATE command is run as a "full DELETE/INSERT," the Logreader send UPDATE as DELETE/INSERT Pair. If you turn on trace flag 8202, then UPDATE commands at the publisher will be always send to the subscriber as DELETE/INSERT pair. 8206 SQL 8 - Supports stored procedure execution with a user specified owner name for SQL Server subscribers or without owner qualification for heterogeneous subscribers. 8203 Display statement and transaction locks on a deadlock error. 8207 Enables singleton updates for Transactional Replication, released with SQL Server 8 SP 1. 8501 Writes detailed information about Ms-DTC context & state changes to the log. 8599 Allows you to use a save-point within a distributed transaction. 8602 Ignore index hints that are specified in query/procedure. 8679 Prevents the SQL Server optimizer from using a Hash Match Team operator. 8687 Used to disable query parallelism. 8721 Dumps information into the error log when AutoStat has been run. 8722 Disable all other types of hints. This includes the OPTION clause. 8744 Disables pre-fetching for the Nested Loops operator. Incorrect use of this trace flag may cause additional physical reads when SQL Server executes plans that contain the Nested Loops operator. For more information about the Nested Loops operator, see the "Logical and physical operators reference" topic in SQL Server 9 BOL. You can turn on trace flag 8744 at startup or in a user session. When you turn on trace flag 8744 at startup, the trace flag has global scope. When you turn on trace flag 8744 in a user session, the trace flag has session scope. 8755 Disable any locking hints like READONLY. Allows SQL Server to dynamically select the best locking hint for the query. 8765 Allows use of variable length data, from ODBC driver; fixes the issue of a field returning the wrong data length. 8783 Allows DELETE, INSERT, and UPDATE statements to honor the SET ROWCOUNT ON setting when enabled. 8816 Logs every two-digit year conversion to a four-digit year. 9059 SQL 8 - Turns back behavior to SP3 after a SP4 installation, this allows to choose an index seek when comparing numeric columns or numeric constants that are of different precision or scale; else would have to change schema/code. 9082 SQL 9 - Stored procedure using views, perform slow compared to ver 8 if views use JOIN operator and contain subqueries. KB 942906 9134 SQL 8 - Does additional reads to test if the page is allocated & linked correctly this checks IAM & PFS. Fixes error 601 for queries under Isolation level read uncommitted. 9259 SQL 9/10 - An access violation occurs on running a query marked by the following message and a dump in the log folder: KB 970279 / 971490 Msg 0, Level 11, State 0, Line 0 - A severe error occurred on the current command. The results, if any, should be discarded. Msg 0, Level 20, State 0, Line 0 - A severe error occurred on the current command. The results, if any, should be discarded. 9268 SQL 8 - When SQL Server runs a parameterized query that contains several IN clauses, each with a large number of values, SQL Server may return the following error message after a minute or more of high CPU utilization: KB 325658 Server: Msg 8623, Level 16, State 1 Internal Query Processor Error: The query processor could not produce a query plan. Contact your primary support provider for more information. End Of File