DBS Control Fields - Advanced SQL Engine - Teradata Database

Database Utilities

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Published
January 2021
Language
English (United States)
Last Update
2021-01-23
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B035-1102
lifecycle
previous
Product Category
Teradata Vantage™

The following table summarizes the DBS Control fields and indicates their groups. The fields are described in more detail in the sections that follow.

The default settings documented here apply to the Teradata Active Enterprise Data Warehouse platform. Default settings on other purpose-built platforms, such as data appliances, may be different.
Field Description Group
AccessLockForUncomRead Determines whether SELECT statements embedded in INSERT...SELECT, UPDATE...SELECT, DELETE...SELECT statements place READ or ACCESS locks on the source table. General
All Other Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of a type not otherwise specified by Storage group fields. Storage
AutoCylPackColdData Determines whether AutoCylPack operations are performed on cylinders storing cold (infrequently accessed) data, in addition to cylinders storing more frequently accessed data.
This field is effective only if you have licensed Teradata Virtual Storage. For more information, see Teradata Vantage™ - Teradata® Virtual Storage , B035-1179 .
File System
AutoCylPackFreeCylThresh The number of free cylinders below which AutoCylPack will not operate. File System
AutoCylPackFSP The percentage of storage space within a cylinder that AutoCylPack operations leave free of data, to allow for future table growth. File System
AutoCylPackInterval The amount of time that the AutoCylPack task waits between checks for new AutoCylPack work. File System
AutoCylPackIOThresh The number of pending I/O operations above which the AutoCylPack task waits for I/Os to complete before continuing. File System
AutoCylPackStyle Determines whether the AutoCylPack task is restricted to packing data more tightly on cylinders, unpacking data, or if it is unrestricted, and can both pack and unpack data to achieve the target FSP. File System
AutoCylPackThresh The threshold difference between actual free space on a cylinder and the target AutoCylPack FSP, below which AutoCylPack will not process the cylinder. File System
AutoProvision Determines whether unknown external logons are automatically added as new users (CREATE USER). General
Bkgrnd Age Cycle Interval Determines the amount of time that elapses between background cycles to write a subset of modified segments in the cache to disk. File System
BLCStats Determines whether block-level compression (BLC) compression ratio information is gathered by COLLECT STATISTICS statements. Optimizer Statistics
BLCStatsForCDS Specifies whether the the COLLECT STATISTICS statement calculates the estimated BLC compression factor for tables. Optimizer Statistics
BlockLevelCompression Indicates whether the block-level compression (BLC) feature is enabled. Compression
CDCProtocol Determines whether the Change Data Capture (CDC) protocol used in database replication scenarios allows for user-defined replication groups or reserved system-defined replication groups for Teradata® Unity™ . General
Century Break Defines how to interpret character-format Teradata Database date input when the input format only has two digits representing the year. General
ChecktableTableLockRetryLimit Specifies that in nonconcurrent mode, CheckTable retries a table check for a specified limit when the table is locked by another application. General
ClientResetAction Controls what happens to queries when Teradata® Unity™ is disconnected or disabled. General
Client Reset Timeout Specifies how long the Relay Services Gateway (RSG) waits for an intermediary to reconnect before taking action. General
CompressGlobalTempFallbackDBs Specifies conditions under which Global Temporary Table data blocks in fallback subtables will be compressed by default. Compression
CompressGlobalTempFallbackCLOBDBs Specifies conditions under which Global Temporary Table CLOB data blocks in fallback tables will be compressed by default. Compression
CompressGlobalTempPrimaryDBs Specifies conditions under which Global Temporary Table data blocks in primary data subtables will be compressed by default. Compression
CompressGlobalTempPrimaryCLOBDBs Specifies conditions under which Global Temporary Table CLOB data blocks in primary data subtables will be compressed by default. Compression
CompressionAlgorithm Specifies the algorithm to use for compressing DBs. Compression
CompressionLevel Determines whether DB compression favors speed or degree of compression. Compression
CompressionZLIBMethod Determines whether the ZLIB compression uses the Intel Integrated Performance Primitives library for better performance on Intel platforms. Compression
CompressPermFallbackDBs Specifies conditions under which permanent data blocks in fallback subtables will be compressed by default. Compression
CompressPermFallbackCLOBDBs Specifies conditions under which permanent CLOB data blocks in fallback subtables will be compressed by default. Compression
CompressPermPrimaryDBs Specifies conditions under which permanent data blocks in primary data subtables will be compressed by default. Compression
CompressPermPrimaryCLOBDBs Specifies conditions under which permanent CLOB data blocks in primary data subtables will be compressed by default. Compression
CompressPJDBs Specifies whether Permanent Journal DBs will be compressed by default. Compression
CompressSpoolDBs Specifies conditions under which spool and volatile data blocks will be compressed by default. Compression
ConnectionBufferSize Controls how much memory is allocated for buffering data between Teradata Database and external data sources. Native Object Store
ConnectionTimeout Controls how long Teradata Database waits for a new connection to an external network to be established when creating or querying a foreign table. Native Object Store
CompressMloadWorkDBs Specifies conditions under which work data blocks will be compressed by default. Compression
CostProfileId Contains the system standard cost profile ID number, which defines the cost profile that the system will use. General
COUNT_mode Determines the data type returned by COUNT operations. General
CPUpdate Determines how column partitions are updated. General
CurHashBucketSize Indicates the number of bits used to identify a hash bucket in the current system configuration. General
CylindersSavedforPERM Saves some number of cylinders for permanent data only. File System
DATASETAttributeSize Denotes the size (number of characters) of attributes returned by the DATASET type dot notation. General
DateForm Defines whether Integer Date or ANSI Date formatting is used for a session. General
DBQL CPU/IO Collection Sets the algorithm used by DBQL to collect CPU and input/output statistics. DBQL CPU/IO collection captures performance data for the execution of a query at the request level and, optionally, at the step level. General
DBQL_AWTDPS_CacheMaximum Limits the size to which the per-AMP AWT DBQL Performance Stats (DPS) cache can grow. This cache holds DBQL request and step data for active requests. Performance
DBQLDefCacheSize Sets the DBQL cache size and determines whether DBQL uses 64K or 1MB data blocks. Performance
DBQLFlushRate Controls the length of time between flushing the Database Query Log (DBQL) cache. General
DBQLLOBCacheSize Determines the amount of cache allocated for DBQL Data Dictionary tables with LOB columns. Performance
DBQLLogLastResp Determines whether DBQL logs a pseudo step labeled “RESP” after the last response of a DBQL logged request completes. General
DBQL Options This field is unused, but reserved for future DBQL use. It should not be changed. General
DBQLXMLPlanMemLimit Specifies the amount of memory used by the XMLPLAN option of DBQL. Performance
DBSCacheCtrl Enables or disables the performance enhancements associated with the Cache Control Page-Release Interface associated with the DBSCacheThr field. Performance
DBSCacheThr Specifies the percentage value to use for calculating the cache threshold when the DBSCacheCtrl field is enabled. Performance
DeadLockTimeout Used by the Dispatcher to determine the interval (in seconds) between deadlock timeout detection cycles. General
DefaultCaseSpec Determines whether character string comparisons consider character case and whether character columns are considered case specific by default in Teradata session mode. General
Default Character Set Specifies the default character set assigned to users if a default character set is not explicitly specified in the CREATE USER statement. General
DefaultTableMode Determines how BLC is managed for Permanent storage tables that have the BLOCKCOMPRESSION option set to DEFAULT, or that do not have the BLOCKCOMPRESSION option explicitly specified when the table is created. When changed, causes TBBLC to immediately start a new cycle. Compression
DefaultPermSkewLimitPercent Specifies the percentage of permanent space that an AMP is allowed to use over and above the per-AMP quota. General
DefaultRowGroupSize If a value is not explicitly provided through user query, determines the size of RowGroups used while creating Parquet files. Native Object Store
DefaultSpoolSkewLimitPercent Specifies the percentage of spool space that an AMP is allowed to use over and above the per-AMP quota. General
DefaultTimeThreshold Defines a default time threshold value in days for statistics collection. Optimizer Statistics
DefaultTempSkewLimitPercent Specifies the percentage of temporary space that an AMP is allowed to use over and above the per-AMP quota. General
DefaultUserChangeThreshold Defines a default data change percentage threshold value for statistics collection. Optimizer Statistics
DefragLowCylProd Determines the number of free cylinders below which cylinder defragmentation can begin. File System
DEPOT Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
DictionaryCacheSize Defines the size of the dictionary cache for each PE on the system. Performance
DictionaryCacheSegmentSize Defines the size of the dictionary segment cache for each PE on the system. Performance
DictionaryDBSize Specifies the maximum size for multirow data blocks in dictionary (database DBC) tables. File System
DisableAutoCylPack Disables AutoCylPack automatic background cylinder packing. Does not affect MiniCylPack operations, which happen when the number of free cylinders is critically low. File System
DisableDATASETValidation Determines whether validation is enabled or disabled for the native Teradata Database DATASET data type. General
DisableJSONValidation Determines whether validation is enabled or disabled for the native Teradata Database JSON data type. General
DisableMergeBlocks Determines whether the file system automatically merges data blocks together on storage cylinders during full table modify operations. Merging several small data blocks into a single larger block can improve system performance by reducing disk I/O. File System
DisablePeekUsing Enables or disables the performance enhancements associated with exposed USING values in parameterized queries. Performance
DisableRecoverableNetProtocol Determines whether the Recoverable Network Protocol is enabled. General
DisableRestartableBLC Determines whether BLC compression and decompression operations will resume after being interrupted by a system restart. File System
DisableSyncScan Enables or disables the performance enhancements associated with synchronized full table scans. Performance
DisableUDTImplCastForSysFuncOp Disables/enables implicit cast/conversion of UDT expressions passed to built-in system operators/functions. General
DisableWAL Forces the writing of data blocks and cylinder indexes directly to disk rather than writing the changes to the WAL log. File System
DisableWALforDBs Forces changed data blocks to be written directly to disk rather than having the changes written to the WAL log. File System
DMLStatementShipping This field is deprecated, and should not be used. General
DotNotationOnErrorCondition Determines how Teradata Database responds when queries using dot notation return a list of values. General
EnableCostProfileTLE Determines whether Optimizer Cost Estimation Subsystem (OCES) diagnostics are enabled in combination with Target Level Emulation (TLE). General
EnableDATASET Determines whether native Teradata DATASET data type support is enabled in Teradata Database. General
EnableDATASETCSV Determines whether the DATASET CSV storage format is available for use byTeradata Database. General
EnableDynamicParameterization Determines whether the Optimizer uses dynamic parameterization of literals in processing repeat requests that differ only in the literal values used in the predicates of WHERE and ON clauses. General
EnableEON Confirms object naming rules are enforced. This field value cannot be changed. General
EnableJSON Determines whether native JSON support is enabled in Teradata Database. General
EnableLogonsMsg Enables or disables the display of “Logons are enabled” message in /var/log/messages on all nodes of a multinode system. General
EnableNOS Determines whether the Native Object Store (NOS) feature is enabled. Native Object Store
EnableTempBLC Determines whether temperature-based block-level compression (TBBLC) is enabled. Compression
EnabNonTempoOp Determines whether nontemporal operations such as NONTEMPORAL DELETE, NONTEMPORAL UPDATE, NONTEMPORAL INSERT, NONTEMPORAL CREATE TABLE AS, and NONTEMPORAL ALTER TABLE can be used. General
EnableSetCostProfile Controls whether the system cost profile can be changed for purposes of system emulation and special-case system tuning. General
ExportOrderBySegmentLimit Specifies the maximum number of segments that can be allocated for FastExport redistribution when data is to be sorted. General
Export Width Table ID Controls the export width of a character in bytes. General
ExternalAuthentication Controls whether Teradata Database users can be authenticated outside (external) of the Teradata Database software authentication system. General
FixSRandomRange Fixes a rare issue with the RANDOM(lower_bound, upper_bound) function that causes it to return a value outside of the specified bounds under certain circumstances. General
ForwardCredential Determines whether to forward authenticated user credential token to Teradata Database. General
Free Cylinder Cache Size Determines how many cylinders are to be managed in File System cache for use as spool cylinders. File System
FreeSpacePercent Determines the percentage of free space reserved on cylinders during bulk load operations. File System
GlobalSpaceSoftLimitPercent Specifies the percentage limit for permanent, spool, and temporary space above the maximum value that the system permits for any database or user. General
GLOBAL TEMP Fallback Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
GLOBAL TEMP Fallback CLOB Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
GLOBAL TEMP Primary Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
GLOBAL TEMP Primary CLOB Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
HashFuncDBC Defines the hashing function that Teradata Database uses. General
HJ2IMHJ Directs Teradata Database to preferentially use the In-Memory Hash Join method to perform hash joins and dynamic hash joins. Performance
HTMemAlloc Specifies the percentage of memory to be allocated to a hash table for a hash join. Performance
IAMaxWorkloadCache Defines the maximum size of the Index Wizard workload cache when performing analysis operations. Performance
IdCol Batch Size Indicates the size of a pool of numbers reserved for generating numbers for rows to be inserted into a table with an identity column. General
InclNTforGrntOrRevokAll Determines whether the NONTEMPORAL privilege is included when GRANT ALL and REVOKE ALL statements specify a user, database, view, or table. General
InListRewriteOption Specifies the type of IN-list processing that will be used for rewrite processing of queries that have IN-lists. Performance
InListRewriteThreshold Specifies the minimum number of values in an IN-list in order for it to qualify for IN-list rewrite query processing. Performance
IVMaxWorkloadCache Defines the maximum size of the Index Wizard workload cache when performing validation operations. Performance
JournalDBSize Determines the maximum size of permanent journal table multirow data blocks, in 512-byte sectors. Rows are written to this journal during INSERT, UPDATE, and DELETE processing. File System
JSON_MaxDepth Determines the level of JSON value nesting allowed during JSON syntax validation. General
JSON_AttributeSize Denotes the size of attributes returned by the JSONExtractValue method and dot notation. General
LargeDepotCylsPerPdisk Determines the number of Depot cylinders the file system allocates to contain large slots (1 MB). A large slot can hold several data blocks during Depot operations. File System
LegacySpaceAcctg Determines whether Teradata Database uses legacy or global space accounting. General
LimitInlistCVal Limits the number of combined values in the IN list. Performance
LockLogger Defines the system default for the lock logger. General
LockLogger Delay Filter Controls whether or not to filter out blocked lock requests based on delay time. General
LockLogger Delay Filter Time Indicates the value at which blocked lock requests with a delay time greater than this value are logged. General
LockLoggerFlushRate Determines the frequency for writing entries to the DBQLXMLLOCKTBL cache. General
LockLogSegmentSize Specifies the size of the Lock Logger segment. General
MaxDecimal Defines the maximum number of Decimal Digits in the default maximum value used in expression typing. General
MaxDownRegions Determines the number of regions (ranges of rows) in a data or index subtable that can be marked as down before the entire subtable is marked down on all AMPs. General
MaxJoinTables Influences the maximum number of tables that can be joined per query block. Performance
MaxLoadAWT Works together with MaxLoadTasks to limit the number of load utility jobs that can run concurrently on the system. General
MaxLoadTasks Works together with MaxLoadAWT to limit the number of load utility jobs that can run concurrently on the system. General
MaxMLOADXAWT Works together with MaxMLOADXTasks to limit the number of MLOADX jobs that can run concurrently on the system. General
MaxMLOADXTasks Works together with MaxMLOADXAWT to limit the number of MLOADX jobs that can run concurrently on the system. General
MaxNumInListRewrite Specifies the maximum number of IN-lists in a single query that can use IN-list rewrite query processing. Performance
MaxParseTreeSegs Defines the maximum number of tree segments that the parser allocates while parsing a request. Performance
MaxRequestsSaved Specifies the number of request-to-step cache entries allowed on each PE on a Teradata Database system. Performance
MaxRowHashBlocksPercent Specifies the proportion of available locks that can be used for rowhash locks by a transaction before the transaction is automatically aborted. General
MaxSetQueryBandSize Defines the maximum query band size in kilobytes that can be set with the SET QUERY_BAND statement. General
MaxSyncWALWrites Determines the maximum number of outstanding WAL log writes to allow before tasks requiring synchronous writes are delayed to achieve better buffering. File System
Memory Limit Per Transaction Specifies the maximum amount of in-memory, temporary storage that the Relay Services Gateway (RSG) can use to store the records for one transaction. General
MergeBlockRatio Specifies the maximum size of a new data block that results from the merging of several smaller blocks. The size is expressed as the ratio of the new block size to the maximum block size specified in the table definition or by the PermDBSize field in DBS Control. File System
MetaDataCapture

Specifies the maximum size of a new data block that results from the merging of several smaller

General
MinDBSectsToCompress Specifies the minimum size DB that will be compressed. DBs smaller than this size will not be compressed. Compression
MiniCylPackHighWaterMark Determines the number of free cylinders above which MiniCylPack is not active. File System
MiniCylPackLowCylProd Determines the number of free cylinders below which the File System will start to perform the MiniCylPack operation in anticipation of the need for additional free cylinders. File System
MinPercentCompReduction Specifies the minimum percentage by which the DB size must be reduced by compression. If compression will not reduce the DB by this amount, the DB will not be compressed. Compression
MLoadDiscardDupRowUPI Determines whether the DBS MultiLoad protocol should silently discard rows with UPI violations or log these rows to the application error table. General
MLOADXUtilityLimits Determines whether MLOADX concurrent task and AWT limits are specific to MLOADX or are shared with other load utilities (FastLoad, MultiLoad, and FastExport). General
MonSesCPUNormalization Determines whether CPU data in workload management (PM/API and Open API) calls is normalized. This affects workload rules defined in Teradata Viewpoint Workload Designer portlet. General
MPS_IncludePEOnlyNodes Excludes PE-only (AMP-less) nodes from MONITOR PHYSICAL SUMMARY Workload Management API statistics calculations. General
NameValidationRule Determines the rules used by Teradata Database to validate object names. General
NewHashBucketSize Specifies the number of bits used to identify hash buckets on the system after the next system initialization or reconfiguration. General
NoDot0Backdown Enables several point release features which, if enabled, prevent a system from being backed down to the prior (“dot 0”) release without a full system initialization (sysinit). General
NumStatisticsCacheSegs Specifies the number of segments maintained for the Optimizer statistics cache on each PE vproc. Performance
ObjectUseCountCollectRate Specifies the amount of time between collections of object use-count data. General
OverrideARCBLC Determines whether database tables restored from archives are block-level compressed according to the system-level BLC defaults. Compression
PERMANENT JOURNAL Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
PermDBAllocUnit Determines the allocation unit for multirow data blocks in units of 512-byte sectors for permanent tables. File System
PermDBSize Determines the maximum size, in consecutive 512-byte sectors, of the multirow data blocks of a permanent table. File System
PERM Fallback Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
PERM Fallback CLOB Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
PERM Primary Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
PERM Primary CLOB Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
PMPC_SessionRateThreshold Determines the threshold above which the session cache is refreshed on demand, based on the session rate and last collection time. Only effective when TDWM Workloads are enabled. General
PMPC_TimeoutSecs Sets timeout interval for certain supported PM API commands. General
PPICacheThrP Specifies the maximum amount of memory to be used for disk read operations that involve multiple partitions. Performance
PrimaryIndexDefault Determines whether Teradata Database automatically creates primary indexes for tables and join indexes created by CREATE TABLE statements that do not include PRIMARY INDEX, PRIMARY AMP [INDEX], NO PRIMARY INDEX, PRIMARY KEY, UNIQUE, and PARTITION BY clauses. General
ProratedSpaceDistPercent Specifies the percentage of newly added space that will be divided evenly and distributed to every database and user during a system reconfiguration. General
PRPDMaxSkewedVals The maximum number of skewed values in a join that should be considered for a PRPD optimization plan. Performance
PRPDSkewPct The percentage of rows in a join to be considered for skew by the optimizer, which determines whether PRPD optimization is used. Performance
ReadAhead Enables or disables the performance enhancements associated with the Read-Ahead Sequential File Access Workload operation. Performance
Read Ahead Count Specifies the number of data blocks that are preloaded in advance of the current file position while performing sequential scans. Performance
ReadLockOnly Enables or disables the special read-or-access lock protocol on the DBC.AccessRights table during privileges validation and on other dictionary tables accessed by read-only queries during request parsing. Performance
RedistBufSize Determines the size (in KB) of units of hashed row redistribution buffers for use by load utilities. Performance
RedriveDefaultParticipation Determines whether or not the Redrive feature is used for all sessions by default. General
RedriveProtection Determines system-level support for the Redrive feature. General
RepCacheSegSize This field is deprecated, and should not be used. General
RequestDuration Controls how long Teradata Database waits for the completion of a request to an external file system after the request timeout or connection timeout has been exceeded and request retries have been commenced. Native Object Store
RequestTimeout Controls how long Teradata Database waits for an external file system request response before aborting the request, re-establishing the connection, and issuing the request again. Native Object Store
RevertJoinPlanning Determines whether the Teradata Database query Optimizer uses newer or older join planning techniques. Performance
RollbackPriority Defines the default priority given to rollback operations. General
RollForwardLock Defines the system default for the RollForward using Row Hash Locks option. General
RoundHalfwayMagUp Indicates how rounding should be performed when computing values of DECIMAL types. General
RoundNumberAsDec Determines whether NUMBER data type uses RoundHalfwaysMagUp rounding or will be rounded away from zero. General
SessionMode Defines the system default transaction mode, case sensitivity, and character truncation rule for a session. General
ShowAllUserNames Determines whether user names, including unauthenticated user names, are shown in Teradata Database logs General
SHOW IN XML Formatted Output Controls the formatting of what is returned by the SHOW statement when the IN XML option is used. General
SHOW IN XML Memory Limit Sets the maximum amount of memory in kilobytes used for internal processing of a request of SHOW statement when the IN XML option is used. Performance
SkewAllowance Specifies a percentage factor used by the optimizer in deciding the size of each hash join partition. Performance
SmallDepotCylsPerPdisk Determines the number of Depot cylinders the file system allocates to contain small slots (1 MB). A small slot can hold a single data block during Depot operations. File System
SnapBypassAggrCache Specifies whether snapshot dumps are suppressed if resource exhaustion is detected when reserving memory for aggregate processing. General
Spill File Path Specifies a directory that the Relay Services Gateway (RSG) can use for spill files. General
SPOOL Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
SpoolBigDBAllocUnit Determines the allocation unit in sectors for multirow big data blocks in spool tables. File System
StandAloneReadAheadCount Specifies the number of data blocks the Teradata utilities will preload when the utilities or File System startup run as standalone tasks. Performance
StepsSegmentSize Defines the maximum size (in KB) of the plastic steps segment (also known as OptSeg). Performance
SyncScanCacheThr Specifies the percentage of File Segment (FSG) cache that is expected to be available for all synchronized full-file scans occurring simultaneously. Performance
SysInit Ensures the system has been initialized properly using the System Initializer utility. Read only. General
SysChangeThresholdOption Defines a change threshold option for statistics recollection. Optimizer Statistics
SysSampleOption Defines a sample option for statistics recollection. Optimizer Statistics
SysInitRelease Specifies the major release number on which the system was last initialized. Read only. General
System TimeZone Hour Defines the System Time Zone Hour offset from Universal Coordinated Time (UTC). General
System TimeZone Minute Defines the System Time Zone Minute offset from Universal Coordinated Time (UTC). General
System TimeZone String Displays the currently set System Time Zone String. General
Target Level Emulation Allows a test engineer to set the costing parameters considered by the Optimizer. General
TempBLCInterval Specifies the amount of time in minutes that the background TBBLC task waits after compressing or uncompressing data before checking for other data to process. Compression
TempBLCIOThresh Specifies the maximum threshold number of outstanding I/O operations that can exist on a node above which the background TBBLC task pauses for a short period Compression
TempBLCPriority Specifies the priority at which the background TBBLC compression task runs. Compression
TempBLCRescanPeriod The number of days the background TBBLC task waits before revalidating the state of TBBLC data to reconfirm that data is appropriately compressed. Compression
TempBLCThresh Specifies the temperature at and below which data blocks are automatically compressed if TBBLC is enabled. When changed, causes TBBLC to immediately start a new cycle. Compression
TempBLCSpread Specifies the percentage above and below the TempBLCThresh field setting at which data should be compressed or uncompressed if TBBLC is enabled. When changed, causes TBBLC to immediately start a new cycle. Compression
TempLargePageSize Specifies the size (in KB) of the large memory allocation storage page used for Relay Services Gateway (RSG) temporary storage. General
Temporal Behavior Determines the default temporal behavior for temporal DDL, queries, and DML statements. General
Temporary Storage Page Size Specifies the size (in KB) of the standard memory allocation storage page size used for Relay Services Gateway (RSG) temporary storage. General
TIM Cache Load Disabled Determines whether the Teradata Intelligent Memory (TIM) cache preload is enabled. This feature loads the most frequently accessed data into cache during system startup, if the FSG cache was not otherwise preserved. Storage
TIM Cache Load Throttle Throttles the Teradata Intelligent Memory (TIM) background cache loading task based on the current number of I/O operations. Storage
TimeDateWZControl Determines whether the time and time zone values returned by built in current time and date functions reflect the session time and time zone. General
TruncRoundReturnTimestamp Determines whether the TRUNC and ROUND system functions return a TIMESTAMP or DATE value when passed a TIMESTAMP value. General
UseVirtualSysDefault This field is no longer used. For cost profiling information, see CostProfileId. General
UncompressReservedSpace Specifies the minimum percentage of storage space that must remain available while DBs are uncompressed using the Ferret UNCOMPRESS command. Compression
UserRetryLimit Determines the number of times Teradata Database will re-try a request to an external file system after the request timeout or connection timeout has been exceeded and request retries have been commenced. Native Object Store
UtilityReadAheadCount Specifies the number of data blocks the Teradata utilities preloads when performing sequential scans. Performance
Version Indicates the version number of the DBS Control Record. General
WAL Buffers Determines the number of WAL append buffers to allocate. File System
WAL Checkpoint Interval Determines the amount of time that elapses between WAL checkpoints. File System
WAL Temperature see Storage Group Determines the initial temperature assigned to data loaded or inserted into tables of this type. Storage
WorkDBSize Specifies the maximum size for multirow data blocks in work tables. File System
XML_Memory Limit Specifies the maximum amount of memory available for operations involving the XML data type. General