Size of delta used in a comparison of two values. If the parameter is not specified, the default value is 1e-10.
Two values A and B are considered equal if at least one of the following conditions is true:

• ABS(A-B) < AlmostZero

• if ABS(A) > AlmostZero and ABS ((A-B)/A) < AlmostZero

• if ABS(B) > AlmostZero and ABS ((A-B)/B) < AlmostZero

Note: Parameter AlmostZero can be changed via the TELL command SET_OPTION.
Note: Parameter was introduced due to the fact that a floating number stored in an SQL database and then read from this database can be marginally different from the original value.

The command for automatic synchronization of the archive database after the start. If this command is not defined, the archive doesn't run this command but presumes that synchronization of archive holes will be performed by an external mechanism.
The command will be run only if the archive is run as an instance (a shadow process).
More information.

When the archive detects a patched hole, it runs recalc for the closed hole. If the parameter ArcsynchroBackground is set to 1, recalc will be performed by the auxiliary calc task. The default value is 0 - recalc will be performed by the main archive write task(s). More information.

When the archive detects a patched hole, it runs recalc for the closed hole, extending over the hole interval by ArcsynchroTimeDelta seconds on both sides. If the parameter is not defined, the default value is 10 seconds (the same as the default value of parameter /TD of arcsynchro utility). More information.

AutoMountPath

Configuration parameter for depository databases on the Sybase platform - more information.

The offset of the start of backup in the given period. It is given in the format HH:MM. It is the offset in hours and minutes.
Note: Backup (parameters BackupOffset, BackupPath, BackupPeriode, BackupPassive) is currently implemented only for Sybase and MS SQL platforms. For Oracle databases, we recommend using RMAN or exp utilities, for the PostgreSQL database pg_dump utility.

Path to the directory where the archive database backup will be stored.

The backup period specified in hours. The value 0 means the backup will not be performed.

Acquires the values 0, 1:

• 1 - The archive will back up an archive database only in passive status (if the archive is connected to HOT and has active status, it will ignore demands for backup of the database),

• 0 - The archive will back up the archive database regardless of its status (active or passive).

This parameter enables chained reading from archives. If the archive being read has a small archive depth and older data is required, the D2000 Archive can continue reading from the derived statistical archive. Since there may be several different statistical archives (and only some statistical functions have the nature of source data), the ChainedReadPrio parameter can be used to define their priorities (from highest to lowest), e.g. F_WGAVG,F_AVG,F_TIMESLICE,F_MAX,F_MIN,NOFUNCTION (if there are several statistical archives created from a single primary archive, the one with the highest priority will be used).
Parameter ChainedReadPrio can be changed via the TELL command SET_OPTION.
Note 1: The NOFUNCTION value represents a statistical archive with no statistical function specified. This can be used to create a user-defined script-filled archive. Specifying a source archive object creates a binding of this statistical archive to the source archive, and then this statistical archive is usable in chained reads.
Note 2: In chained reading, the statistical archives calculated On Read are currently ignored.

When CommitCount values are inserted into the archive database, D2000 Archiv calls Commit. The default value is 1000. By increasing this value, the frequency of Commit operations will be lowered. This parameter can be set separately for active and passive archives.
Parameters CommitCountActive and CommitCountPassive can be changed via the TELL command SET_OPTION.

Note 1: The Archive is considered to be active if it reads data from the archive database. The archive is passive if it is connected to a standby server or if it is a passive instance of an archive.
Note 2: Parameters CommitCount and CommitTime were implemented primarily for the Oracle database because of the hard disk space saving. Operation Commit causes an increment of the SCN number, which is written into the control file of the database. When the archive is heavy-laden, the disk area where the control file is located can become damaged, and the control file itself will be unreadable.

The number of deleted values (by the TELL command DELETE_DATA or by the action DELETEARCHDATA), which are considered equivalent to one inserted value, as far as Commit is concerned (see the description of CommitCountActive/CommitCountPassive). The default value is 100 deleted values.
The parameter is put into effect during deletion of a larger number of values, where it causes Commits to occur (and, e.g., for an Oracle database, it avoids excessive use of the UNDO tablespace).

Time (in seconds), after which the archive performs periodic Commit. The default value is 60 seconds. This parameter can be set separately for active and passive archives. See notes at CommitCountActive/CommitCountPassive parameters.
Parameters CommitTimeActive and CommitTimePassive can be changed via the TELL command SET_OPTION.

CursorCacheSize

Cache size for precompiled cursors (precompiled INSERT or UPDATE commands).
The parameter is supported from version 7.01.007 release 26. In the previous versions, there was a cache for INSERT statements, its fixed size was 1500 items, and UPDATE statements were not cached at all. From version 7.01.007 release 26, the cache size is dynamic, and if the parameter of DWORD type does not exist (default), the cache size is not limited.
One object of Historical value type requires a pair of INSERT and UPDATE precompiled cursors.
Optimum is the cache size greater than the number of objects of the Historical value type, and there is no need to remove precompiled commands from the cache.

On Sybase 6.0, 7.0, 9.0, 12.0, on MS SQL, and MSDE platforms, a cache with more than 3000 cursors was tested.

Note 1: It is not usually needed to define the parameters CursorCacheSize and CursorCacheUpdates.
Note 2: To detect the status of the cursor cache, use the Tell command SHOW_INFO.
Note 3: On the Oracle platform, this parameter is ignored - precompiled INSERT cursors are all kept in cache, precompiled UPDATE cursors are either all or none, depending on parameter CursorCacheUpdates.
Note 4: On both the Oracle and PostgreSQL platforms, the number of cursors is limited to about 64,000 per connection. Because each object can use 2 cursors (INSERT and UPDATE; except for PostgreSQL if the Upsert parameter is enabled), the CursorCacheSize parameter should be set to 32000 * WriteThreadsCount for applications with a large number of archive objects (64000 * WriteThreadsCount if the Upsert parameter is enabled) if the number of archive objects is greater than this value. Otherwise, the archive may crash with an error (for PostgreSQL):
myapp_Archiv - (HY001) Maximum number of statements exceeded. ErrorCode = 203

If the value of the parameter is 1, the cache will store precompiled UPDATE commands too.
The parameter is supported from version 7.01.007 release 26. In the previous versions, there was a cache for INSERT statements, its fixed size was 1500 items, and UPDATE statements were not cached at all.
From version 7.01.007 release 26, the cache for UPDATE commands is enabled by default. If the parameter of the DWORD type doesn't exist (default), the cache for UPDATE commands is enabled.

Note 1: It is not usually needed to define the parameters CursorCacheSize and CursorCacheUpdates.
Note 2: To detect the status of the cursor cache, use the command SHOW_INFO.

Value 0 (default) means that the archive doesn't use time slices.
Value 1 enables time slices in the archive database for all archive objects.
Value 2 enables time slices in the archive database for structured archives only.
Note: Changing the value to 1 or 2 means a non-reversible conversion of the archive database.
Therefore, we recommend backing up the archive database before this parameter is changed. Backup database + data from a converted database (via arcsynchro) can be used to revert to the non-slicing archive.
Note: migration from value 1 (time slices for all archive objects) to value 2 (time slices for structured archives only) is possible. Thereafter, it is necessary to run a TELL command CLEANUP_SLICES to remove time slices of simple archive objects and to move values from these time slices to the original data tables.

The parameter can be used to change the default value of the username used by the archive to connect to an archive database.
The default username is:

• dba for Sybase, MSSQL, and PostgreSQL platforms,

• <nazov_aplikacie_>_archiv for Oracle platform (e.g. MyTest_archiv).

Note: This parameter can be used to simplify the renaming or migration of an application using an Oracle archive. Otherwise, export of all archive tables and import under a different Oracle user/scheme (e.g., MyNewTest_archiv) is necessary. If depositories are configured, setting the parameter TrezorPrefix is recommended.

The parameter can be used to change the default value of the password used by the archive to connect to an archive database.
The parameter only needs to be set if the password differs from the default password.
Note: if the password of the database user for the D2000 Server on the PostgreSQL platform was changed, where there is a common user for the configuration, monitoring, and archive database, this password, stored in encrypted form in the application registers (X1), is used first. If the DbPassword parameter is defined, it has a higher priority.

If time slices are used in the archive, the value 1 (default) means that during periodic delete in the archive database, also data from slices zero (original data tables) will be deleted. The value 0 turns the deletion off so that during the periodic delete, no data is deleted from slices zero, but the whole slice will be emptied (via SQL command TRUNCATE TABLE) when it is older than the configured "History depth" parameter of the historical value. The advantage is speed (the database is not burdened by DELETE commands, which generate REDO logs and optionally by following automatic reorganization), the disadvantage is up to double the disk space needed for the database (until all slices zero get truncated).
For new applications, there is no need to modify this parameter. For old applications upgraded to version 8 and above, we recommend keeping the value of this parameter to 1.
Note: If time slices are not used, the DeleteInSlice0 parameter must be set to 1; otherwise, periodic deletes of the archive will not be performed (original archive tables are considered to be slices zero).

If time slices are used in the archive, the value 0 (default) means that during periodic delete in the archive database, data from time slices won't be deleted, but the whole slice will be emptied (via SQL command TRUNCATE TABLE) when it is older than the configured "History depth" parameter of the historical value. The advantage is speed (the database is not burdened by DELETE commands, which generate REDO logs and optionally by following automatic reorganization), the disadvantage is an increase in the disk space needed for the database by the data contained in one time slice (i.e., 1 month).
Value 1 means that during periodic delete in the archive database, the DELETE commands (and optionally, if configured, automatic reorganization) will be executed.
We recommend keeping the value of this parameter to 0.

Setting the parameter DiskUsageWarning to a value of 0 disables the archive warning (ODBC version only) that free space on a disk with the archive database is below 10% of the archive database size.
Default value 1 means that a warning is displayed by all D2000 HI processes.
Note: Parameter DiskUsageWarning can be changed via the TELL command SET_OPTION.

The parameter specifies how often (number of minutes) the archive will generate a warning that free space on a disk with the archive database is below 10% of the archive database size. The default value is 15 minutes.
Note: Parameter DiskUsageWarning can be changed via the TELL command SET_OPTION.

If the recalculations of older values of computed historical values by auxiliary calc task are on (see the RecalcImmediateDepth parameter), setting the DropOldRequests parameter to a value of 1 causes the recalculations not to be performed but instead to be written to a file in the application directory. The name of the file is SELF_ARCHIV_DROPPED_CALCS.DAT for the process SELF.ARC or name_ARCHIV_DROPPED_CALCS.DAT for the process name.ARC. The contents of this file can be processed by a TELL command CALC_OLD_REQUESTS. The default value of the parameter DropOldRequests=0 means that the recalculations will be performed.
Note: The parameter DropOldRequests can be changed via the TELL command SET_OPTION DROP_OLD_REQUESTS ON/OFF.

This parameter has a similar meaning for archive on Sybase/MS SQL/PostgreSQL platforms, as has TNS_Service_Name parameter for archive on the Oracle platform. That is, it enables the change of a predefined DSN (Application.Archiv for SELF.ARC or Application.Arcname.Archiv for Arcname.ARC), which the process D2000 Archiv uses to connect to the archive database. It enables, e.g., running two instances of the archive on a single computer.
If the parameter is not defined or it is empty, then the predefined DSN will be used.
Note 1: The parameter is implemented starting with D2000 version 8.0.
Note 2: If the value of parameter DSN_Override is set, then editing of the archive in D2SMC or in module D2000 Application Manager in Enterprise Management Console does not affect the predefined DSN of the archive, but the DSN whose name is specified by DSN_Overridparameter.

ForceSelectIndex

If the parameter of DWORD type is set to a non-zero value, the FORCE INDEX clause of the SELECT command will be used when reading from Sybase Anywhere version 9 and higher.
Sybase version 9.0.1 and higher implements the FORCE (index_name) clause in the SELECT command. The clause avoids using the SQL command optimizer and orders to use the selected index in the SELECT command. The ForceSelectIndex parameter has been implemented to quicken reading from the archive database, but its real benefit needs to be tested yet.

Note 1: If reading from the archive database on Sybase is too slow, check whether the Optimization_goal option is set to First-row.
Do the following: open Sybase Central, connect to the archive database, right-click on it, select Options, then Optimization_goal option, and check whether its value is First-row. If not, change its value from All-rows to First-row and click Set Permanent Now.
Note 2: To find whether the ForceSelectIndex parameter is enabled, use the Tell command SHOW_INFO.

FreeSpaceQuery

The parameter of the STRING type determines how the process D2000 Archiv queries free space in the archive database on the Oracle platform:

• USER - free space is queried from the USER_FREE_SPACE database view (default value),

• DBA - free space is queried from the DBA_FREE_SPACE database view (user must have read access to this view),

• NONE - free space is not queried.

Free space in the database is displayed as a FreeSpace item in the predefined structured variable SV._System_ArchivPerformance. If the parameter FreeSpaceQuery is not specified or differs from the values listed above, free space will be queried from the view USER_FREE_SPACE.
Note 1: The parameter was implemented due to a random deadlock of the archive in a specific application, which was caused by querying the free space from the database view USER_FREE_SPACE. Implementing the FreeSpaceQuery parameter and changing its value first to NONE and later to DBA solved the problem.
Note 2: Starting from D2000 version 7.02.005, the database parameters FreeSpace, AutoExtensible, and DatabaseSize are queried every 100th commit. That means that the frequency of changes is influenced by the parameters CommitCountActive/CommitCountPassive, and CommitTimeActive/CommitTimePassive.

Value of 1 switches the archive cache into a new mode - so-called isochronous cache. In this mode, the cache of the process D2000 Archiv works as follows:

• The values of all Historical value type objects (except for the objects calculated during reading - OnRead archives - which are not cached) are kept in the cache for the same time (for exceptions, see the description of the parameter IsoCacheFullDepth).

• The time for keeping the values in cache (time depth of the cache) is dynamically adjusted to keep the cache size close to the value specified by the MaxCacheSize parameter.

• Values from the cache are also used for reading values for graphs and events.

• Values from the cache are used even if the cache does not contain the whole required time interval (the rest of the values are read from the database).

• If the cache of a specific archived object does not contain enough data and reading from the database follows, the read data is pre-pended to the cache (only the values that are not older than the current time depth of the cache).

• Values read from the cache have the 'M' flag set.

If the parameter IsochronousCache is set to the value 0, the cache behaves as originally designed, i.e.:

• The cache keeps only the values of those Historical value type objects, which are needed for other calculated and statistic archived objects (only for those calculated continuously - Continuous archives).

• Time for keeping the values in cache (time depth of the cache) is set separately for every historical object, depending on the maximum period of the depending calculated and the statistical archived objects. If the cache size specified by the MaxCacheSize parameter is insufficient, the least-read archived objects are purged from the cache.

• The values from the cache are used only for statistical calculations, not for reading values for graphs and events.

• The values from the cache are used only if the cache contains the whole required time interval.

• Older data than that already contained in the cache of a specific archived object is never prepended to the cache.

By enabling the isochronous cache and by specifying sufficient cache size (depending on the archive's load) it is possible to achieve "in memory archive" when the time depth of the cache (e.g., several hours) is sufficient for most graphs and script operations, which speeds up the opening of graphs and decreases the load on the archive database. Enabling the isochronous cache is recommended for "delayed" archives, which contain a lot of archived objects calculated on demand (OnDemand archives), which are calculated behind the real-time (e.g., with a 1-hour time lag). If a sufficient time depth of the cache is set, the values necessary for the calculation of statistical and calculated archived objects will be available from the cache, which will speed up the calculations.

Note: Parameter IsochronousCache can be changed via the TELL command SET_OPTION.
Note: Dynamic adjustments of the time depth of the cache can be monitored via the System Console after enabling the debug category DBG.ARCHIV.CACHE.

The parameter is meaningful only if the Isochronous cache is enabled by setting the IsochronousCache parameter.
Value 0 means that the time for keeping the object's values (time depth of the cache) is equal for all objects.
Value 1 means that if such calculated or statistical objects exist, and their period is longer than the current time depth of the cache, the values of source archived objects will have prolonged time depths.

Example:
Let there be a primary on-change archived object H.X.
Let there be a current time depth of the cache equal to 45 minutes (depending on the value of MaxCacheSize and the archive's load).
Let there be a statistic archived object H.X.AVG defined as a 3-hour average of H.X.
If IsoCacheFullDepth=0, the time depth of H.X will be 45 minutes.
If IsoCacheFullDepth=1, the time depth of H.X will be 3 hours, so that during the periodic calculation of H.X.AVG, all data from the last period will be available.

Note: Parameter IsoCacheFullDepth can be changed via the TELL command SET_OPTION.

The parameter is meaningful only if the Isochronous cache is enabled by setting the IsochronousCache parameter.
Value 1 means that the isochronous cache is to be automatically populated by reading values from the archive database when Archiv is started. Populating is performed for all archive objects with the exception of on-read calculated archived objects. The time-depth of reading is determined by a dynamic parameter IsoCacheDepth.
Note: Loading of values for the isochronous cache can be manually triggered by a TELL command FILL_CACHE.
Note: For archive running as an instance, the loading of values is performed after all archive holes have been patched (see the ArcsynchroAuto parameter). For a single archive, not running as an instance, the loading of values is performed immediately after archive initialization.
Note: Setting the archive instance as active is recommended only after the isochronous cache is filled so that standard read requests are not blocked.

The parameter is meaningful only if the Isochronous cache is enabled by setting the IsochronousCache parameter.
The parameter determines the time-depth of the isochronous cache in seconds. The parameter is dynamic, i.e., changed dynamically during the archive's run, depending on the archive's load, to keep the size of the isochronous cache to a configured value MaxCacheSize. If a time-depth changes, the archive will automatically save the new value of the parameter IsoCacheDepth into the registry. Note: parameter IsoCacheDepth can be modified by a TELL command SET_OPTION, which can be used during expansion of the isochronous cache (SET_CACHE), manual modification of parameter IsoCacheDepth, and manual triggering of isochronous cache data loading (FILL_CACHE).

Size of the memory [MB] that can be used by the archive process to create a dynamic cache. Using the archive cache significantly speeds up the evaluation of statistical and evaluated archive objects.
Note: Parameter MaxCacheSize can be changed via the TELL command SET_CACHE.

MaxOpenTrezors

The maximum number of depository databases that can be opened for reading at the same time.
Using a Sybase Anywhere Engine database (i.e., not a Network Server) limits the maximum number of simultaneous user connections to 10. If creating depository databases is enabled, the process D2000 Archiv uses 6 connections for its routine work (reading, writing, deleting/reorganizing, configuration, current depository database, and previous depository database). There are 4 connections left to read from the depository databases mounted, so if creating depository databases is enabled, the parameter MaxOpenTrezors must be set to the value of at most 4.
If the maximum number of simultaneous user connections is reached, the process D2000 Archiv will display the following error message when reading from the depository database:
(08004) [Sybase][ODBC Driver][Adaptive Server Anywhere]Database server connection limit exceeded ErrorCode=-102.

The default value of the parameter is 10 (for reasons of D2000 system backward compatibility).
The value can be higher for Sybase Anywhere Network Server.
Starting with version D2000 7.01.21, it is possible to disable the limit by setting the parameter MaxOpenTrezors to 0.

Note:

1. The parameter can be used only for the Sybase platform and will be ignored for Oracle and PostgreSQL platforms.

2. The Tell command LIST_TREZOR on the Sybase platform lists all opened depository databases and their names (the Open column).

3. On the Sybase Anywhere 12 platform, crashes of the D2000 Archive were observed when the depository database was closed (crashes were inside the ODBC driver). The solution was to set the MaxOpenTrezors parameter to a relatively high value (1000) so there were no disconnects of the depositories.

OldValIgnoreAge

If the parameter value is nonzero, the values older than OldValIgnoreAge hours will be discarded. If the debugging category DBG.ARCHIV.IGNORED_VALUES.OLD is enabled, then the discard information will be written to the archive log. This parameter is useful as a way to protect the archive from old communication values (since subsequent massive calculations of dependent historical objects could overload the archive).

Dropping values refer to old values from communications (which only go to the archive and have an archive flag of OldVal) as well as values without the OldVal flag. It does not apply to values inserted from the script or values manually changed in HI.

Parameter OldValIgnoreAge can be changed via the TELL command SET_OPTION.

Old values from the communication (which go only to the archive and have the archive flag OldVal set) will be processed by the auxiliary calc task.
This parameter optimizes the performance of the archive in specific applications. If the communication generates significant amounts of old values (e.g., protocol NMEA-0183 on the File I/O line), setting the parameter to 1 alleviates the main archive task by moving old values to the auxiliary calc task.
The default value of 0 means that the old values will be processed by the main archive task.
Parameter OldValOnAuxTask can be changed via the TELL command SET_OPTION.

The value can be 0 or 1. If OneThreadForGraph = 1, only one thread will be used for one instance of a graph when reading its data. If OneThreadForGraph = 0, the number of threads, defined in the parameter ReadThreadsCount, will be used.

Configuration parameter for depository databases on the PostgreSQL platform - more information.

A value that determines SQL commands used during the reorganization of previous time slices on the PostgreSQL platform:

• 0 - use the VACUUM command (default)

• 1 - use the VACUUM FULL command

• 2 - use the CLUSTER command

• 3 - no reorganization will be performed

Note 1: value will be in effect also for TELL command REORGANIZE for SLICE=-3 ("previous time slice") and SLICE=-4 ("all slices older than current time slice").
Note 2: Parameter PG_ReorganizeSlice can be changed via the TELL command SET_OPTION.

A value determining a time interval (in seconds) after which previous time slices will be reorganized on the PostgreSQL platform. The default value is 3600 + 600 seconds, i.e., an hour and ten minutes after the previous time slices ceased to be used.
Note: Parameter PG_ReorgSliceTime can be changed via the TELL command SET_OPTION. 

Configuration parameter for depository databases on the PostgreSQL platform - more information.
Parameter PG_TrezorFileMulti can be changed via the TELL command SET_OPTION.

Configuration parameter for depository databases on the PostgreSQL platform - more information.

Configuration parameter for depository databases on the PostgreSQL platform - more information.

Configuration parameter for depository databases on the PostgreSQL platform - more information.

Configuration parameter for depository databases on the PostgreSQL platform - value 1 turns on the old way of working (a permanent database connection to every attached depository database) that has higher demands on the database server. A value of 0 (default) causes the connection to be open only during the reading of a particular depository database.

The parameter specifies the number of threads that provide parallel access to data from the archive. Possible values 1...10. The default value is 1. A value greater than 1 requires a license for the "High Performance Archive" pack.

Experimental parameter. When reading time interval <Start, Stop> from the archive, the queried interval will be <Start-ReadTimeBeforeStart, Stop>. For specific applications, it is possible to tune the parameter ReadTimeBeforeStart to achieve that also the first value before the time interval <Start, Stop>, which is otherwise read by another SELECT command, will be obtained.
The default value of the parameter ReadTimeBeforeStart is 0 seconds.

Parameter to limit future recalculations. If non-zero, its value specifies the number of seconds into the future that dependent archives will be recalculated after a value with a time in the future arrives. The default value of 0 means that no restrictions are applied.

Note: The parameter does not affect user-requested recalculations (via the RECALC command or the CALCONDEMANDSTAT action).

Time depth (in seconds) of the recalcs of computed historical values, which are performed by the main archive task. Default value 0 means that all recalcs of historical values are performed by the main archive task. A non-zero value means that recalcs older than RecalcImmediateDepth seconds will be performed by an auxiliary calc task so that the main archive task will not be overloaded by recalcs of older historical values.
Recalcs of calculated historical values are caused by the arrival of a historical value with an older timestamp. If the recalculated time interval also contains values older than RecalcImmediateDepth seconds, it will be recalculated by an auxiliary calc task.
Note 1: Parameter RecalcImmediateDepth can be changed via the TELL command SET_OPTION RecalcImmediateDepth seconds/OFF.
Note 2: Recalcs requested by a TELL command RECALC are performed by the main archive task.

The parameter activates the optimization of the repeated recalculation of the time interval.
The optimized recalculation consists of reading the original target data before the calculation and then comparing the original data with the recalculated data. Data that is identical is not deleted and reinserted.
Note: Parameter RecalcOptimize can be changed via the TELL command SET_OPTION RecalcOptimize ON/OFF.

Specifies the size of the recalculated time interval (in seconds) intended for parallelization. The parameter is meaningful for a multiwrite archive (i.e., if the value of parameter WriteThreadsCount > 1 the archive uses multiple write tasks). If the parameter RecalcParallelInterval is set to a non-zero value (the default value is 0), then the recalcs of time intervals greater than the specified value which are initiated externally (by a TELL command or from a script) will not be performed by a write task assigned to the recalculated historical value, but by a write task with the smallest number of recalc requests in its queue will be used.
This parameter is intended to speed up recalcs in balance systems that use structured evaluated/statistical historical values. If a request for a recalc of whole structured historical values arrives, by default, the recalcs of all rows of a structured historical value are performed by a single write task assigned to this historical value. Setting the RecalcParallelInterval parameter to a non-zero value will cause the recalcs of individual rows to be parallelized. Still, the resulting calculated values will be inserted into the database by a single write task assigned to this historical value.
Note 1: This parameter does not influence the recalcs caused by the arrival of a new value, only the recalcs initiated by a TELL command or from a script.
Note 2: Parameter RecalcParallelInterval can be changed via the TELL command SET_OPTION

The parameter (specified in hours) for the process D2000 Archiv defines a limit for the time interval for the recalculation of statistics. If a request for recalculation of a longer time interval is generated (internally or as a result of the TELL command RECALC), it will be split into several shorter requests with a time interval not longer than the limit defined by the RecalcTimeIntervalLimit parameter. This parameter is meant to be a safeguard against the crash of the process D2000 Archiv during recalcs of long time intervals entered by a user or caused by the arrival of the old value.
Note 1: If RecalcTimeIntervalLimit = 0, then the time interval is not limited (default behavior).
Note 2: Parameter RecalcTimeIntervalLimit can be changed via the TELL command SET_OPTION RecalcTimeIntervalLimit hours/OFF.

The parameter can acquire the value 0 or 1.
If the parameter RacalcUseTrezor = 1, the archive will also read data from the depository database during recalculation.
The depositories will be read when the required data are behind the archive depth of the object that is being read.
The parameter can also be set by the TELL command SET_OPTION RECALC_USE_TREZOR ON.

The offset of the beginning of periodic reorganization in the given period. It is given in the format HH:MM. It is the offset in hours and minutes. See the description of the ReorganizePeriode parameter.

Periodic reorganization period, given in hours. During the periodic reorganization, all archive tables are reorganized irrespective of the number of deleted rows and the time of the last reorganization (see ReorganizeTableRowLimit and ReorganizeTableTimeLimit parameters).
The value 0 means periodic reorganization will not be performed.
Note: Periodic reorganization is influenced by start parameters /DBCA, /DBCY, /DBCP, and /DBCA in the same way as normal automatic reorganization.

The parameters define the conditions for the process D2000 Archiv to perform automatic reorganization of the archive database. The parameter ReorganizeTableRowLimit defines the number of deleted rows, and the parameter ReorganizeTableTimeLimit specifies the number of hours. (e.g., ReorganizeTableRowLimit=50000 and ReorganizeTableRowLimit=24 --> the archive table is to be automatically reorganized after 50000 values of the archive table are deleted but not more often than once in 24 hours).

Warning: The parameters can be only used for archives on Oracle, PostgreSQL, Sybase 9.0, and higher platforms.

If the value of the parameter is 1, a Select is performed before Insert/Update to find out whether a value with a specific timestamp is already in a database. If it is, an Update is performed; otherwise Insert is performed. When using this parameter, it is necessary to turn on the IsochronousCache parameter and set the RecalcImmediateDepth parameter to 0.
The default value of this parameter is 0.
Note: parameter can be used for archives using a PostgreSQL database to minimize transaction ID (XID) generation when used against a DSN with "Level of rollback on errors" set to Transaction.
Note: for PostgreSQL starting with version 9.5, it is possible (and recommended) to use the Upsert parameter to minimize XID generation.
Note: the arcsynchro utility has a parameter /UF serving the same purpose.

The parameter activates copying of user flags (FA, FB, … FO, FP) from source values ​​to calculated values ​​of statistical historical values. If the parameter value is 1, the value of will statistical historical values will have a summary of all user flags of the source values.
Note: The StatKeepFlags parameter can be changed via the TELL command SET_OPTION.

The parameter activates the copying of the Weak flag from the source values to the calculated values of the statistical historical values.. If the value of the parameter is 1, the value of will statistical historical values will have the Weak flag set if at least one source value has this flag (plus the standard setting of the Weak flag remains as a consequence of the poor quality of the source data configured on the archived value by the Validation Criteria parameter.
Note: The StatKeepWeak parameter can be changed via the TELL command SET_OPTION.

The parameter defines the mode of processing values ​​of columnar and structured historical objects in conditions of parallel writing to the database (WriteThreadsCount > 1). The following values ​​are supported:

• 0 (default) - all items of columnar and structured historical objects are processed by the same write task

• 1 (column) - all items of column historical objects, as well as items of structured historical objects in the same column, are processed by the same write task

• 2 (item) - each item of the column and structured historical objects is assigned to some of the write tasks

Note: modes 1 and 2 enable the processing of structured archive objects to be optimized; on the other hand, they require the cursor for the archive object to be compiled on each writing task. However, in the case of large applications, cursors may run out (there can be a maximum of 65535 open cursors on one task/database connection - these are ODBC or OCI limitations, not D2000 limitations).

The parameter activates logging of a recalc interval longer than the parameter value. The default value is 30 * 24 * 3600 seconds. A value of 0 disables logging.
Note: The ReportLongRecalc parameter can be changed via the TELL command SET_OPTION.

If the value of the parameter is 1, information about completed conversions is sent to the D2000 Server process and written to the log database. If the value of the parameter is 0, this information is not sent to the D2000 Server process or written to the log database.
The default value of the parameter is 1.
Note: The SystemLogging parameter can be changed via the TELL command SET_OPTION.

Activates TimescaleDB support and converts data tables to hypertables on the PostgreSQL platform.

• A value of 0 (default) means that the archive does not use the TimescaleDB extension.

• A value of 1 enables hypertables in the archive for all historical objects.

• A value of 2 enables hypertables in the archive for structured historical objects.

This text parameter is related to TimescaleDB support and specifies the time interval size for each hypertable chunk in PostgreSQL interval syntax. The recommended value is 30 days or 1 month.

This optional text parameter is related to TimescaleDB support and specifies the compression time for each hypertable chunk in PostgreSQL interval syntax. Chunks that contain older data will be compressed. If this parameter is not specified, the value of TimescaleDBInterval is used.

Configuration parameter for the archive database on the Oracle platform - it defines the name of the archive tablespace. If this parameter is empty, the name APPLICATION_NAME_TS_ARCHIV is used. If the name is wrong, the process D2000 Archiv will not report the information about the archive tablespace in the system structure SV._System_ArchivPerformance (columns DatabaseSize, AutoExtensible, FreeSpace, DataSize).
Note: The parameter Tablespace_Name can be changed via the TELL command SET_OPTION Tablespace_Name name_of_tablespace.

Configuration parameter for the archive database on the Oracle platform - defines the TNS of the database that the archive tablespace is in.

TNS_Service_Name_Trezor

Configuration parameter for depository databases on the Oracle platform -  more information.

Trezor_Active_Only

Configuration parameter for depository databases on the Oracle platform - more information

Configuration parameter for depository databases:

• on the Sybase platform - more information

• on the Oracle platform - more information

Configuration parameter for depository databases:

• on the Sybase platform - more information

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

Configuration parameter for depository databases:

• on the Sybase platform - more information

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

TrezorCountDatafiles

Configuration parameter for depository databases on the Oracle platform - more information.

TrezorCountSegments

Configuration parameter for depository databases:

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

TrezorDatafileSizeStep

Configuration parameter for depository databases on the Oracle platform -  more information.

TrezorDatafileSuffix

Configuration parameter for depository databases on the Oracle platform -  more information.

TrezorMaxDatafileSize

Configuration parameter for depository databases on the Oracle platform -  more information.

TrezorNologging

Configuration parameter for depository databases on the Oracle platform -  more information.

TrezorPath

Configuration parameter for depository databases:

• on the Sybase platform - more information

• on the Oracle platform - more information

TrezorPostCompressCmd

Configuration parameter for depository databases:

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

TrezorPostCompressPar

Configuration parameter for depository databases:

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

Configuration parameter for depository databases:

• on the Sybase platform - more information

• on the Oracle platform - more information

• on the PostgreSQL platform - more information

Configuration parameter for depository databases on the Oracle platform -  more information.

TrezorReadOnlyTimeout

Configuration parameter for depository databases on the Oracle platform - more information.

TrezorStartDatafileSize

Configuration parameter for depository databases on the Oracle platform - more information.

Setting the parameter to value 1 activates the usage of the SQL command "UPSERT" (a combination of Insert and Update SQL commands), which is supported by PostgreSQL database starting with version 9.5. In this case, insertion of values into the archive and depository databases will be performed by command INSERT .. ON CONFLICT .. DO UPDATE. This enables setting the archive ODBC parameter "Level of rollback on errors" to the value Transaction (instead of the current standard value Statement). That radically decreases the generation of XIDs (database transaction IDs related to the existence of savepoints separating every single SQL statement) and consequently reduces the related overhead of PostgreSQL (frequent vacuuming to avoid "transaction ID wraparound").
Note: for versions of PostgreSQL older than 9.5, it is possible to use the SelectBeforeUI parameter to minimize XID generation.
Note: the utility arcsynchro has a parameter /UP serving the same purpose.

An hour marking the beginning and the end of working hours. During this time, time-consuming archive operations are minimized to increase the availability of the archive.
It is possible to enter not only the standard working day (e.g. WorkingHoursStart=6, WorkingHoursEnd=18) but also the day covering midnight (e.g. WorkingHoursStart=14, WorkingHoursEnd=5 or WorkingHoursEnd=29). The default value of 0 for both parameters turns off the working hours functionality.
Note: Parameters affect periodic deletion and reorganization on all database platforms, as well as detection of free space in the archive tablespace on the Oracle platform.
Note: WorkingHoursStart and WorkingHoursEnd can be changed via the TELL command SET_OPTION.
Note: If a large archive database on the PostgreSQL platform is backed up with pg_dump and the backup takes several hours to create, and time slices are used (DataTableSlices parameter), the archive delete task may block when trying to clean up the entire time slice that is beyond the archive depth (TRUNCATE TABLE). This blocking (caused by locks created by pg_dump) may subsequently cause write tasks to block. Therefore, we recommend that you configure the working hours in the above scenario to include the interval during which PostgreSQL is backed up.

The number of threads used for parallel writing of the values to the database. Possible values 1...32. The default value is 1. A value greater than 1 requires a license for the "High Performance Archive" pack. The parameter is implemented starting with version 8.00.011. For archives with heavy load running on PostgreSQL or Oracle database, we recommend setting this value equal to the number of processors (respective cores of processors) of the archive server. For archives using the Sybase database, no significant improvements have been observed when writing was parallelized.