DSE Commands and Qualifiers

The general format of DSE commands is:

command [-qualifier[...]] [object[,...]]

DSE interprets all numeric input as hexadecimal, except for time values, the values for the following qualifiers when used with CHANGE -FILEHEADER: -BLK_SIZE=, DECLOCATION=, -KEY_MAX_SIZE=, -RECORD_MAX_SIZE, -REFERENCE_COUNT=, -TIMERS_PENDING and -WRITES_PER_FLUSH, and the value for -VERSION= when used with the REMOVE and RESTORE commands. These conventions correspond to the displays provided by DSE and by MUPIP INTEG.

ADD

Adds a record to a block. The format of the ADD command for blocks with a level greater than zero (0) is:

ADD [-B[LOCK]=[block] {-OFFSET=offset|-RECORD=record} -STAR -POINTER=block

or

ADD [-B[LOCK]=[block] {-OFFSET=offset|-RECORD=record} -KEY=key -POINTER=pointer

The format of the ADD command for level 0 blocks is:

ADD [-B[LOCK]=[block] {-OFFSET=offset|-RECORD=record} -KEY=key -DATA=string

The ADD command requires either the -OFFSET or -RECORD qualifier to position the record in the block, and either the -KEY or the -STAR qualifier to define the key for the block.

The -STAR qualifier is invalid at level 0 (a data block). The ADD command requires the -DATA qualifier at level 0 or the -POINTER qualifier at any other level to provide record content.

Qualifiers of ADD

-B[LOCK]=block-number

Specifies the block to receive the new record.

On commands with no -BLOCK= qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

-D[ATA]=string

Specifies the data field for records added to a data block. Use quotation marks around the string and escape codes of the form \a\b, where "a" and "b" are hexadecimal digits representing non-printing characters. \\ translates to a single backslash. \'\' translates to a NULL value.

Incompatible with: -STAR,-POINTER

-K[EY]=key

Specifies the key of the new record. Enclose M-style global references, including the leading caret symbol (^), in quotation marks (" ").

Incompatible with: -STAR

-O[FFSET]=offset

Adds the new record at the next record boundary after the specified offset.

Incompatible with: -RECORD, -STAR

-P[OINTER]=pointer

Specifies the block pointer field for records added to an index block. The -POINTER qualifier cannot be used at level 0. Note this means that to add pointers at level 0 of the Directory Tree you must specify a string of bytes or temporarily change the block level.

Incompatible with: -DATA

-R[ECORD]=record-number

Specifies a record number of the new record.

Incompatible with: -OFFSET,-STAR

-S[TAR]

Adds a star record (that is, a record that identifies the last record in an indexed block) at the end of the specified block. The -STAR qualifier cannot be used at level 0.

Incompatible with: -DATA,-KEY,-OFFSET,-RECORD

Examples for ADD

DSE>add -block=6F -record=57 -key="^Capital(""Mongolia"")" -data="Ulan Bator"

This command adds a new record with key ^Capital("Mongolia") at the specified location. Note that this command is applicable to level 0 blocks only.

Example:

DSE>add -star -bl=59A3 -pointer=2

This command adds a star record in block 59A3. Note that this command is applicable to blocks > level 0.

Example:

DSE>add -block=3 -record=4 -key="^Fruits(4)" -data="Grapes"

Suppose your database has 3 global nodes -- ^Fruits(1)="Apple", ^Fruits(2)="Banana", and ^Fruits(3)="Cherry", then the above command adds a new node ^Fruits(4)="Grapes" at record 4. Note that this command is applicable to level 0 blocks only. The interpreted output as a result of the above command looks like the following:

Block 3   Size 4B   Level 0   TN 4 V6
Rec:1  Blk 3  Off 10  Size 14  Cmpc 0  Key ^Fruits(1)
      10 : | 14  0  0  0 46 72 75 69 74 73  0 BF 11  0  0 41 70 70 6C 65|
           |  .  .  .  .  F  r  u  i  t  s  .  .  .  .  .  A  p  p  l  e|
Rec:2  Blk 3  Off 24  Size D  Cmpc 8  Key ^Fruits(2)
      24 : |  D  0  8  0 21  0  0 42 61 6E 61 6E 61                     |
           |  .  .  .  .  !  .  .  B  a  n  a  n  a                     |
Rec:3  Blk 3  Off 31  Size D  Cmpc 8  Key ^Fruits(3)
      31 : |  D  0  8  0 31  0  0 43 68 65 72 72 79                     |
           |  .  .  .  .  1  .  .  C  h  e  r  r  y                     |
Rec:4  Blk 3  Off 3E  Size D  Cmpc 8  Key ^Fruits(4)
      3E : |  D  0  8  0 41  0  0 47 72 61 70 65 73                     |
           |  .  .  .  .  A  .  .  G  r  a  p  e  s                     |

Example:

$dse add -star -bl=1 -pointer=2

This command adds a star record in block 1. Note that this command is applicable to blocks > Level 0.

Example:

$ dse add -block=4 -key="^Vegetables" -pointer=7 -offset=10

This command creates a block with key ^Vegetables pointing to block 7.

Example:

DSE> add -record=2 -key="^foo" -data=\'\' 

This example adds a new node (set ^foo="") as the second record of the current database block.

ALL

Applies action(s) specified by a qualifier to all GDS regions defined by the current global directory.

The format of the ALL command is:

AL[L]
[
-B[UFFER_FLUSH]
-C[RITINIT]
-D[UMP] -A[LL] 
-[NO]F[REEZE]
-O[VERRIDE]]
-REF[ERENCE]
-REL[EASE]
-REN[EW]
-S[EIZE]
-W[CINIT]           
]
  • This is a very powerful command; use it with caution.

  • Be especially careful if you have an overlapping database structure (for example, overlapping regions accessed from separate application global directories).

  • If you use this type of database structure, you may need to construct special Global Directories that exclude overlapped regions to use with DSE.

Qualifiers

-ALL

Displays additional information on the database most of which is useful for FIS in diagnosing issues.

Meaningful only with: -D[UMP]

-BUFFER_FLUSH

Flushes to disk the file header and all pooled buffers for all regions of the current global directory.

Incompatible with: -RENEW

-C[RITINIT]

Initializes critical sections for all regions of the current directory.

Incompatible with: -RENEW, -RELEASE, -SIEZE

[Caution] Caution

Never use CRITINIT while concurrent updates are in progress as doing so may damage the database.

-[D]UMP

Displays fileheader information.

Compatible with: -A[LL]

-[NO]F[REEZE]

Freezes or prevents updates all regions of the current global directory.

  • The FREEZE qualifier freezes all GDS regions except those previously frozen by another process . Regions frozen by a particular process are associated with that process .

  • A frozen region may be unfrozen for updates in one of two ways: The process which froze the region may unfreeze it with the -NOFREEZE qualifier; or another process may override the freeze in conjunction with the -OVERRIDE qualifier.For more information on a preferred method of manipulating FREEZE, refer to “FREEZE ”.

  • By default, the -NOFREEZE qualifier unfreezes only those GDS regions that were previously frozen by a process . Once a region is unfrozen, it may be updated by any process .To unfreeze all GDS regions of the Global Directory, use the -OVERRIDE qualifier.

  • DSE releases any FREEZE it holds when it exits, therefore, use the same DSE invocation or SPAWN to perform operations after executing the ALL -FREEZE command.

Incompatible with: -RENEW

-O[VERRIDE]

Overrides the ALL -FREEZE or ALL -NOFREEZE operation.

When used with -NOFREEZE, -OVERRIDE unfreezes all GDS regions, including those frozen by other users.

When used with -FREEZE, -OVERRIDE freezes all GDS regions, including those frozen by other processes associating all such freezes with the current process. The current process must then use -NOFREEZE to unfreeze the database; any other process attempting a -NOFREEZE should also have to include the -OVERRIDE qualifier.

Meaningful only with: [NO]FREEZE

-REF[ERENCE]

Resets the reference count field to 1 for all regions of the current global directory.

  • A Reference count is a file header element field that tracks how many processes are accessing the database with read/write permissions.

  • This qualifier is intended for use when DSE is the only process attached to the databases of the curent global directory. Using it when there are other users attached produces an incorrect value.

Incompatible with: -RENEW

-REL[EASE]

Releases critical sections for all regions of the current global directory.

Incompatible with: -CRITINIT, -RENEW, -SEIZE

-REN[EW]

Reinitializes the critical sections (-CRITICAL) and buffers (-WCINIT), resets reference counts (-REFERENCE_COUNT) to 1, and clears freeze (-NOFREEZE) for all regions of the current global directory .

  • -RENEW requires confirmation.

  • The RENEW action will cause all current accessors of the affected database regions to receive a fatal error on their next access attempt.

  • This operation is dangerous, drastic, and a last resort if multiple database have hangs that have not yielded to other resolution attempts; there is almost never a good reason to use this option.

-S[EIZE]

Seizes the critical section for all regions of the current global directory. The -SEIZE qualifier is useful when you encounter a DSEBLKRDFAIL error, generated when DSE is unable to read a block from the database.

Incompatible with: -RENEW, -RELEASE, -CRITINIT

-W[CINIT]

Reinitializes the buffers for all regions of the current global directory.

-WCINIT requires confirmation.

[Caution] Caution

This operation is likely to cause database damage when used while concurrent updates are in progress.

Incompatible with: -RENEW

Examples of ALL

Example:

DSE> all flush -buffer_flush

This command flushes the file header and cache buffers to disk for all regions.

Example:

DSE> ALL -CRITINIT

This command initializes critical sections for all regions of the current directory.

Example:

DSE> ALL -FREEZE
DSE> SPAWN "mumps -dir"

The first command freezes all regions of the current global directory. The second command creates an child (shell) process and executes the "mumps -dir" command. Then type S ^A=1 at GTM prompt. Notice that the command hangs because of the DSE FREEZE in place.

Example:

DSE> ALL -NOFREEZE -OVERRIDE

This command removes the FREEZE on all current region including the FREEZE placed by other users.

Example:

DSE> ALL -REFERENCE

This command sets the reference count field in the file header(s) to 1.

Example:

DSE> ALL -RELEASE

This command releases critical sections owned by the current process for all regions of the current global directory.

Example:

DSE> ALL -RENEW

This command reinitializes critical sections, buffers, resets the reference count to 1, and clears freeze for all regions of the current global directory.

Example:

DSE> ALL -SEIZE

This command seizes all critical sections for all regions of the current global directory.

Example:

DSE> ALL -WCINIT

This command reinitializes the buffers for all regions of the current global directory.

Buffer_flush

Flushes the file header and the current region's buffers to disk.

The format of the BUFFER_FLUSH command is:

B[UFFER_FLUSH]

The BUFFER_FLUSH command has no qualifiers.

CHange

The CHANGE command changes fields of a block, file, or record header.

The format of the CHANGE command is:

CH[ANGE]

The CHANGE command either has a -FILEHEADER qualifier or an implicit or explicit -BLOCK qualifier, plus one or more of their associated qualifiers, to define the target of the change.

-BL[OCK]=block-number and one or more of the following qualifiers:

-BS[IZ]=block-size
-L[EVEL]=level
-TN[=transaction-number]
-OF[FSET]=offset
-RE[CORD]=record-number
-CM[PC]=compression-count
-RS[IZ]=record-size

or

-F[ILEHEADER] and one or more of the following qualifiers:

-AB[ANDONED_KILLS]=value
-AVG_BLKS_READ=Average-blocks-read
-B_B[YTESTREAM]=transaction-number
-B_C[OMPREHENSIVE]=transaction-number
-B_D[ATABASE]=transaction-number
-B_I[NCREMENTAL]=transaction-number
-B_R[ECORD]=transaction-number
-BLK_SIZE=block-size
-BLO[CKS_FREE]=free-blocks
-CU[RRENT_TN]=transaction-number
-COM[MITWAIT_SPIN_COUNT]=boolean
-DATA[_RESERVED_BYTES]=reserved-bytes
-DEC[LOCATION]=value
-DEF[_COLLATION]=value
-ENCRYPTION_HASH
-FL[USH_TIME][=delta-time]
-FR[EEZE]=value
-FU[LLY_UPGRADED]=boolean
-GV[STATSRESET]
-HA[RD_SPIN_COUNT]=Mutex-hard-spin-count
-HE[XLOCATION]=value
-INDEX[_RESERVED_BYTES]=reserved-bytes
-INT[ERRUPTED_RECOV]=boolean
-JNL_YIELD_LIMIT=journal-yeild-limit
-KE[Y_MAX_SIZE]=key-max-size
-KI[LL_IN_PROG]=value
-M[ACHINE_NAM]=value
-N[ULL_SUBSCRIPTS]=value
-NO[CRIT]
-OV[ERRIDE]
-Q[DBRUNDOWN]
-RC_SRV_COUNT
-RE_READ_TRIGGER=read-trigger
-REC[ORD_MAX_SIZE]=record-max-size
-REF[ERENCE_COUNT]=reference-count
-REG[_SEQNO]=sequence-number
-RESERVED_BYTES=reserved-bytes
-SLEE[P_SPIN_COUNT]=mutex-sleep-spin-count
-SPIN[_SLEEP_MASK]=mutex-spin-sleep-mask
-STRM_NUM=stream-number STRM_REG_SEQNO=hexa
-TIM[ERS_PENDING]=integer
-TO[TAL_BLKS]=total-blocks
-TR[IGGER_FLUSH]=trigger-flus
-UPD_RESERVED_AREA=reserved-area
-UPD_WRITER_TRIGGER_FACTOR=trigger-factor
-W[RITES_PER_FLUSH]=writes-per-flush
-WAIT_DISK=wait-disk
-Zqgblmod_S[EQNO]=sequence-number
-Zqgblmod_TN=sequence-number

CHANGE -BLock Qualifiers

This section describes -BLOCK and all of its qualifiers.

-BL[OCK]=block_number

Specifies the block to modify. The -BLOCK qualifier is incompatible with the -FILEHEADER qualifier and all qualifiers related to -FILEHEADER.

-BLOCK is the default qualifier. On commands with neither a -BLOCK nor a -FILEHEADER qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

Incompatible with: -FILEHEADER and qualifiers used with -FILEHEADER

The following qualifiers operate on a block header.

-BS[IZ]=block_size

Changes the block size field of the specified block.

  • block_size is in hexadecimal form.

  • Decreasing the block size can result in loss of existing data.

[Note] Note

The block size must always be less than or equal to the block size in the file header.

Use only with: -BLOCK, -LEVEL, -TN

-L[EVEL]=level

Changes the level field for the specified block.

[Note] Note

DSE lets you change the level of a bitmap block to -1 (the value of the level for a bitmap block) when the bitmap level gets corrupted and takes on an arbitrary value. Note that you should specify -1 in hexadecimal form, that is, FF.

Use only with: -BLOCK, -BSIZ, -TN

Example:

DSE >change -level=FF

-TN[=transaction_number]

Changes the transaction number for the current block.

  • When a CHANGE command does not include a -TN=, DSE sets the transaction number to the current transaction number.

  • Manipulation of the block transaction number affects MUPIP BACKUP -BYTESTREAM, and -ONLINE.

Use only with: -BLOCK, -BSIZ, -LEVEL

-OF[FSET]=offset

Specifies the offset, in bytes, of the target record within the block. If the offset does not point to the beginning of a record, DSE rounds down to the last valid record start (for example, CHANGE -OFFSET=10 starts at -OFFSET=A, if that was the last record).

Use only with: -BLOCK, -CMPC, and -RSIZ.

-RE[CORD]=record_number

Specifies the record number of the target record.

Use only with: -BLOCK, -CMPC, and -RSIZ.

-CM[PC]=compression_count

Change the compression count field of the specified record.

  • The compression count specifies the number of bytes at the beginning of a key that are common to the previous key in the same block.

  • Because compression counts propagate from the "front" of the block, this can potentially change the keys of all records following it in the block. If the goal is to change only a single record, it may be preferable to add a new record and remove the old one.

Use only with: -BLOCK, -RECORD, -OFFSET, -RSIZE

-RS[IZ]=record_size

Changes the record size field of the specified record.

[Caution] Caution

Changing -RSIZ impacts all records following it in the block.

Use only with: -BLOCK, -RECORD, -CMPC, -OFFSET

Example:

DSE> change -record=3 -rsiz=3B -block=2

This command changes the record size of record 3 block 2 to 59 (Hex: 3B) bytes.

CHANGE -FIleheader Qualifiers

This section describes the -FILEHEADER qualifier and the other qualifiers that operate on a file header.

-FI[LEHEADER]

Modifies a file header element that you specify with an associated qualifier.

Incompatible with: -BSIZ, -CMPC, -TN, -LEVEL, -OFFSET, -RECORD, -RSIZ

-AB[ANDONED_KILLS]=value

Changes the value of the Abandoned Kills field. The value can be "NONE" or a decimal positive integer.

Use only with: -FILEHEADER

-BLK[_SIZE]=block_size

Changes the decimal block size field of the current file.

  • DSE does not allow you to change the block size to any arbitrary value. It always rounds the block size to the next higher multiple of 512.

  • Use the CHANGE -BLK_SIZE qualifier only upon receiving instructions from FIS and only in conjunction with the -FILEHEADER qualifier. This DSE command cannot change the working block size of a database and is useful only under very limited and extrordinary circumstances. If you need to change the block size on a database file, unload the data with MUPIP EXTRACT (or an appropriate alternative), change the global directory with GDE to specify the new block size, recreate the database with MUPIP CREATE and reload the data with MUPIP LOAD (or appropriate alternative).

Use only with: -FILEHEADER

-BLO[CKS_FREE]=free blocks

Changes the hexadecimal free blocks field of the current file.

Use this to correct a value that MUPIP INTEG reports as needing a correction, but note that the "correct" value reported by INTEG may go out-of-date with the next update. It may be necessary to calculate a delta value from the INTEG report, FREEZE the region with DSE, DUMP the current -FILEHEADER value, then apply the delta and CHANGE the -BLOCKS_FREE, and finally turn -OFF the FREEZE.

Use only with: -FILEHEADER

-B[YTESTREAM]=transaction_number

Changes the transaction number in the file header of the last incremental backup to the value specified. Use this qualifier only in conjunction with the -FILEHEADER qualifier. For compatibility issues with priot versions, this can still be specified as -B_COMPREHENSIVE.

-D[ATABASE]=transaction_number

Changes the hexadecimal transaction number in the file header of the last comprehensive backup to the value specified. Use this qualifier only in conjunction with the -FILEHEADER qualifier. For compatibility issues with prior versions, this can still be specified as -B_COMPREHENSIVE.

-B_R[ECORD]=transaction_number

Changes the hexadecimal transaction number in the file header field that maintains this information about the last -RECORD backup.

-CO[RRUPT_FILE]=boolean

Indicates whether or not a region completed a successful recovery with the MUPIP JOURNAL -RECOVER command. Possible values are: T[RUE] or F[ALSE].

Changing this flag does not correct or cause database damage. When CORRUPT_FILE is set to TRUE, the DSE DUMP command displays a message like the following:

%GTM-W-DBFLCORRP, /home/gtmnode1/mumps.dat Header indicates database file is corrupt
[Caution] Caution
After a CHANGE -FILEHEADER -CORRUPT=TRUE, the file is unavailable to future GT.M access other than DSE. Under normal conditions, there should never be a need to change this flag manually. A MUPIP SET -PARTIAL_BYPASS_RECOV sets this flag to false.

Use only with: -FILEHEADER

-COM[MITWAIT_SPIN_COUNT]=value

Specifies the decimal number of times a GT.M process waiting for control of a block to complete a block update should spin before yielding the CPU when GT.M runs on SMP machines. When run on a uniprocessor system, GT.M ignores this parameter. On SMP systems, when a process needs a critical section that another process has, if critical sections are short (as they are by design in GT.M), spinning a little with the expectation that the process with the critical section will release it shortly provides a way to enhance performance at the cost of increased CPU usage. Eventually, a process awaiting a critical section yields the CPU if spinning for a little does not get it the needed critical section. Note that on heavily loaded systems, increasing COMMITWAIT_SPIN_COUNT may not trade off CPU for throughput, but may instead degrade both. If you set the COMMITWAIT_SPIN_COUNT to 0, the waiting process performs a sequence of small sleeps instead of the spins or yields.

The default value is 16.

Use only with: -FILEHEADER

-CU[RRENT_TN]=transaction_number

Changes the hexadecimal current transaction number for the current region.

  • Raising the -CURRENT_TN can correct "block transaction number too large" errors

  • This qualifier has implications for MUPIP BACKUP -INCREMENTAL and -ONLINE.

  • Used with the -BLOCK qualifier, CURRENT_TN places a transaction number in a block header.

Use only with: -FILEHEADER

-DATA[_RESERVED_BYTES]=data_reserved_bytes

Sets data reserved bytes. GT.M will not utilize whatever space is reserved in performing updates on data blocks in the database.

Use only with: -FILEHEADER

-DECLOCATION

Specifies an offset with the file header. If -VALUE is specified (in decimal), GT.M puts it at that location.

Use only with: -FILEHEADER

-E[NCRYPTION_HASH]

Changes the hash of the password stored in the database file header if and when you change the hash library. For more information on key management and reference implementation, refer to Chapter 12: “Database Encryption.

[Caution] Caution

An incorrect hash renders the database useless.

Use only with: -FILEHEADER

-[NO]EPOCHTAPER

Sets a flag that indicates whether or not epoch tapering should be done. The default value is -EPOCHTAPER.

For more information, refer to “Region Qualifiers”.

-FL[USH_TIME][=delta_time]

Changes the flush_time default interval (in delta_time).

  • The time entered must be between zero and one hour. Input is interpreted as decimal.

  • A -FLUSH_TIME with no value resets the -FLUSH_TIME to the default value (one second for BG and 30 seconds for MM).

  • The units of delta_time are hours:minutes:seconds:centi-seconds (hundredths of a second). For example, to change the flush time interval to a second, delta_time would be 00:00:01:00. To change it to 30 minutes, delta_time would be 00:30:00:00. Valid values for the qualifier are one centi-second to one hour.

Use only with: -FILEHEADER

-FR[EEZE]=value

Sets availability of the region for update. Possible values are: T[RUE] or F[ALSE]. Use to "freeze" (disable database writes) or "unfreeze" the database.

Use only with: -FILEHEADER

For information about a preferred method of manipulating FREEZE, refer to “FREEZE ” of the General Database Management chapter.

DSE releases -FREEZE when it EXITs. To hold the database(s), CHANGE -FILEHEADER -FREEZE=TRUE and then SPAWN to perform other operations.

-FU[LLY_UPGRADED]=boolean

Sets a flag that indicates whether or not the database was fully upgraded from a prior version to the current database format. The value is either T[RUE] or F[ALSE].

Use only with: -FILEHEADER

-GV[STATSRESET]

Resets all the database file header global access statistics to 0. Note that this erases all statistics previously accumulated in the database file header.

Use only with: -FILEHEADER

-HEXLOCATION

Specifies a hexadecimal offset with the file header. If -VALUE is specified, GT.M puts it at that location.

Use only with: -FILEHEADER

-INDEX[_RESERVED_BYTES]=index_reserved_bytes

Sets index reserved bytes. GT.M will not utilize whatever space is reserved in performing updates on index blocks in the database.

Use only with: -FILEHEADER

-INT[ERRUPTED_RECOV]=boolean

Sets a flag that indicates whether or not a recovery with the MUPIP JOURNAL -RECOVER command was interrupted. The value is either T[RUE] or F[ALSE].

Use only with: -FILEHEADER

-K[EY_MAX_SIZE]=key_max_size

Changes the decimal value for the maximum allowable key size. Reducing KEY_MAX_SIZE can restrict access to existing data and cause GT.M to report errors. Do not create incompatible key and record sizes.

Before permanently changing the key size using DSE, use GDE to check that the appropriate Global Directory contains the same key size for the region. This prepares for future MUPIP CREATEs and performs a consistency check on the key and record size values. For more information on key and record sizes, refer to Chapter 4: “Global Directory Editor.

Use only with: -FILEHEADER

-KI[LL_IN_PROG]=value

Changes the value of the KILLs in progress field. The value can be "NONE" or a positive decimal integer.

Use only with: -FILEHEADER

-N[ULL_SUBSCRIPTS]=value

Controls whether GT.M accepts null subscripts in database keys.

  • value can either be T[RUE], F[ALSE], ALWAYS, NEVER, or EXISTING. See GDE chapter for more information on these values of null_subscript.

  • Prohibiting null subscripts can restrict access to existing data and cause GT.M to report errors.

  • The default value is never.

  • DSE cannot change the null subscript collation order. Instead, use GDE to change the null subscript collation order, MUPIP EXTRACT the current content, MUPIP CREATE the database file(s) with the updated collation and MUPIP LOAD the content.

Use only with: -FILEHEADER

-OV[ERRIDE]

Releases or "steals" a FREEZE owned by another process.

Use only with: -FREEZE

-[NO]Q[DBRUNDOWN]

Sets a flag that indicates whether or not the database is enabled for quick rundown. The default value is -NOQDBRUNDOWN.

For more information, refer to “Region Qualifiers”.

-REC[ORD_MAX_SIZE]=record_max_size

Changes the decimal value for the maximum allowable record size. Use the -RECORD_MAX_SIZE qualifier only in conjunction with the -FILEHEADER qualifier. Reducing RECORD_MAX_SIZE can restrict access to existing data and cause GT.M to report errors. Do not create incompatible key and record sizes.

Before making a permanent change to the records size using DSE, use GDE to check that the appropriate Global Directory contains the same record size for the region. This prepares for future MUPIP CREATEs and performs a consistency check on the key and record size values. For more information on key and record sizes, refer to Chapter 4: “Global Directory Editor.

-REF[ERENCE_COUNT]=reference_count

Sets a field that tracks how many processes are accessing the database with read/write permissions. MUPIP INTEG and DSE use decimal numbers for -REFERENCE_COUNT. To accurately determine the proper reference count, restrict CHANGE -FILEHEADER -REFERENCE_COUNT to the case where the process running DSE has exclusive (standalone) access to the database file. When DSE has sole access to a database file the -REFERENCE_COUNT should be one (1). This is an informational field and does not have any effect on processing.

-REG[_SEQNO]=sequence-number

In an LMS environment, this sets the "Region Seqno" field. For more information, refer to Chapter 7: “Database Replication.

-RESERVED_BYTES=reserved_bytes

Sets both data and index reserved bytes. GT.M will not utilize whatever space is reserved in a block.

Use only with: -FILEHEADER

-RESYNC_S[EQNO]=sequence-number

In an LMS environment, this sets the hexadecimal value of the "Resync Seqno" field. For more information, refer to Chapter 7: “Database Replication.

-RESYNC_T[N]=sequence-number

In an LMS environment, this sets the hexadecimal value ofthe "Resync transaction" field. For more information, refer to Chapter 7: “Database Replication.

-SPIN_SLEEP_MASK]=hexadecimal-mask

Changes the hexadecimal Spin sleep time mask that controls the maximum time in nanoseconds the process sleeps on a sleep spin; zero (0), the default causes the process to just yield to the OS scheduler.

Use only with: -FILEHEADER

-SLEE[P_SPIN_COUNT]=integer

Changes the hexadecimal Mutex Sleep Spin Count that controls the number of times a process waiting on a shared resource (usually a database) suspends its activity after exhausting its Mutex Hard Spin Count and before enquing itself to be awakened by a process releasing the resource

Use only with: -FILEHEADER

-[NO]STD[NULLCOL]

Changes the collation of empty string ("NULL") subscripts for the database file. Although it is not the default, STDNULLCOLL is required with certain other characteristics, and highly recommended in any case. If you change this when there are existing "NULL" subscripts the results may be problematic. FIS recommends you establish this characteristic with GDE and load data with a consistent setting.

Use only with: -FILEHEADER

-STRM_NUM=stream-number -STRM_R[EG_SEQNO]=str_num's_region_sequence_number

Changes the hexadecimal values of Stream and its Reg Seqno. Use -STRM_NUM and -STRM_REG_SEQNO together as part of the same CHANGE -FILEHEADER command.

Use only with: -FILEHEADER

-TI[MERS_PENDING]=timers_pending

Sets a field that tracks the decimal number of processes considering a timed flush. Proper values are 0, 1, and 2.

Use the CHANGE -TIMERS_PENDING qualifier only upon receiving instructions from FIS.

Use only with: -FILEHEADER

-TO[TAL_BLKS]=total_blocks

Changes the hexadecimal total blocks field of the current file. Use only with: -FILEHEADER

[Caution] Caution

The total blocks field should always reflect the actual size of the database. Change this field only if it no longer reflects the database size.

-TR[IGGER_FLUSH]=trigger_flush

Sets the decimal value for the triggering threshold, in buffers, for flushing the cache-modified queue.

Use the CHANGE -TRIGGER_FLUSH qualifier only upon receiving instructions from FIS, and only in conjunction with the -FILEHEADER qualifier.

-WR[ITES_PER_FLUSH]=writes_per_flush

Set the decimal number of block to write in each flush. The default value is 7.

Use only with -FILEHEADER

Examples for CHANGE

Example:

DSE> change -block=3 -bsiz=400

This command changes the size of block 3 to 1024 bytes.

Example:

DSE> change -block=4 -tn=10000

This command changes sets the transaction number to 65536 (Hex: 10000) for block 4.

Example:

DSE> change -block=2 -record=4 -CMPC=10 -key="^CUS(""Jones,Vic"")"

This command changes the compression count of the key ^CUS(Jones,Vic) to 10. It is assumed that the key CUS(Jones,Tom) already exists. The following table illustrates how GT.M calculates the value of CMPC in this case.

RECORD KEY

COMPRESSION COUNT

RESULTING KEY in Record

CUS(Jones,Tom)

0

CUS(Jones,Tom)

CUS(Jones,Vic)

10

Vic)

CUS(Jones,Sally)

10

Sally)

CUS(Smith,John)

4

Smith,John)

Example:

DSE> dump -fileheader

This command displays fields of the file header.

Example:

DSE> change -fileheader -blk_siz=2048

This command changes the block size field of the fileheader to 2048 bytes. The block field must always be a multiples of 512 bytes.

Example:

DSE> change -fileheader -blocks_free=5B

This command changes the blocks free fields of the file header to 91 (Hex: 5B). Example:

Example:

DSE> change -fileheader -b_record=FF

This command sets the RECORD backup transaction to FF.

Example:

DSE> change -fileheader corrupt_file=FALSE

This command sets the CORRUPT_FILE field to false.

Example:

DSE> change -fileheader -current_tn=1001D1BF817

This command changes the current transaction number to 1100000000023 (Hex: 1001D1BF817). After you execute this command, subsequent transaction numbers will be greater than 1001D1BF817.

Example:

DSE> change -fileheader -flush_time=00:00:02:00
This command changes the flush time field of the file header to 2 seconds.

Example:

DSE> change -fileheader -freeze=true

This command makes the default region unavailable for updates.

Example:

DSE> change -fileheader -key_max_size=20

This command changes the maximum key size to 20. Note that the default max key size is 64.

Example:

DSE> CHANGE -FILEHEADER -NULL_SUBSCRIPTS="EXISTING"

This command changes the Null Subscripts field of the file header to EXISTING. Note that DSE cannot change the null subscript collation order. See GDE chapter for more information on changing the null subscript collation.

Example:

DSE> change -fileheader -record_max_size=496

This command sets the maximum record size as 496 for the default region.

Example:

DSE> change -fileheader -reference_count=5

This command sets the reference count field of the file header to 5.

Example:

DSE> change -fileheader -timers_pending=2

This command sets the timers pending field of the file header to 2.

Example:

DSE> change -fileheader -TOTAL_BLKS=64

This command sets the total size of the database to 100 (Hex: 64) blocks.

Example:

DSE> change -fileheader -trigger_flush=1000

This command sets the Flush Trigger field of the file header to 1000. Note the default value of Flush Trigger is 960.

Example:

DSE> change -fileheader -writes_per_flush=10

This command changes the number of writes/flush field of the file header to 10. Note that the default value for the number of writes/flush is 7.

Example:

DSE> change -fileheader -zqgblmod_seqno=FF

This command changes the ZGBLMOD_SEQNO field to 255(Hex: FF).

CAche

Operates on the cache of a database having BG access method. The format of the CACHE command is:

CA[CHE] 
[
-ALL
-RE[COVER]
-SH[OW]
-VE[RIFY]
] 

Qualifiers of CACHE

-RE[COVER] [-ALL]

Resets the cache of a database having BG access method to a "clean" state.

  • With -ALL specified, DSE includes all region of the current global directory for cache recovery.

  • Attempt DSE CACHE -RECOVER only if a DSE CACHE -VERIFY commands reports the cache is "NOT clean".

-SH[OW]

Displays the cache data structure information. All values are in 8-byte hexadecimal form. If the database has encryption turned on, SHOW additionally displays an element that gives information about the encrypted global buffer section in shared memory.

-VE[RIFY] [-ALL]

Verifies the integrity of the cache data structures as well as the internal consistency of any GDS blocks in the global buffers of the current region.

  • With -ALL specified, DSE performs cache verification on all regions of the current global directory.

  • It reports the time, the region and a boolean result indicating whether the cache is clean or NOT clean. If you see "NOT clean" in report, execute DSE CACHE -RECOVER as soon as possible to reset the cache in a clean state.

Examples for CACHE

Example:

DSE> CACHE -VERIFY

This command checks the integrity of the cache data structures as well as the internal consistency of GDS blocks in the global buffers of the current region.

Example:

DSE> CACHE -VERIFY -ALL
Time 26-FEB-2011 14:31:30 : Region DEFAULT : Cache verification is clean
Execute CACHE recover command if Cache verification is "NOT" clean.

This command reports the state of database cache for all regions.

Example:

DSE> CACHE -RECOVER

This command reinitializes the cache data structures of the current region and reverts the cache of a database having BG access to "clean" state.

Example:

DSE> CACHE -SHOW
File    /home/jdoe/node1/areg.dat
Region  AREG
Region AREG : Shared_memory       = 0x00002B6845040000
Region AREG :  node_local         = 0x0000000000000000
Region AREG :  critical           = 0x0000000000010000
Region AREG :  shmpool_buffer     = 0x0000000000023000
Region AREG :  lock_space         = 0x0000000000125000
Region AREG :  cache_queues_state = 0x000000000012A000
Region AREG :  cache_que_header   = 0x000000000012A030 : Numelems = 0x00000407 : Elemsize = 0x00000098
Region AREG :  cache_record       = 0x0000000000150458 : Numelems = 0x00000400 : Elemsize = 0x00000098
Region AREG :  global_buffer      = 0x0000000000177000 : Numelems = 0x00000400 : Elemsize = 0x00000400
Region AREG :  db_file_header     = 0x0000000000277000
Region AREG :  bt_que_header      = 0x00000000002B7000 : Numelems = 0x00000407 : Elemsize = 0x00000040
Region AREG :  th_base            = 0x00000000002C71D0
Region AREG :  bt_record          = 0x00000000002C7200 : Numelems = 0x00000400 : Elemsize = 0x00000040
Region AREG :  shared_memory_size = 0x00000000002D8000
DSE>

CLose

The CLOSE command closes the currently open output file.

The format of the CLOSE command is:

CL[OSE]

The CLOSE command has no qualifiers.

CRitical

Displays and/or modifies the status and contents of the critical section for the current region. The format of the CRITICAL command is:

CR[ITICAL] 
[
-A[LL] 
-I[NIT]
-O[WNER]
-REL[EASE]
-REM[OVE]
-RES[ET]
-S[EIZE]
]
  • The critical section field identifies, by its process identification number (PID), the process presently managing updates to database.

  • Think of a critical section as a common segment of a train track. Just as a train moves through the common segment as quickly as possible, the same way a process moves as quickly as possible through any critical section so that other processes can use it.

  • By default, the CRITICAL command assumes the -OWNER qualifier, which displays the status of the critical section.

Qualifiers of CRITICAL

-A[LL]

Display all ids of processes owning critical section from all regions. If there are no processes owning critical section in a region, ALL displays "the CRIT is currently unowned" message for each region.

-I[NIT]

Reinitializes the critical section.

  • The -INIT and -RESET qualifiers together cause all GT.M processes actively accessing that database file to signal an error.

  • FIS recommends against using -INIT without the -RESET parameter when other processes are actively accessing the region because it risks damaging the database.

Use only with: -RESET

-O[WNER]

Displays the ID of the process at the head of the critical section. DSE displays a warning message when the current process owns the critical section.

Use alone

Example:

DSE> critical -OWNER
Write critical section is currently unowned

-REL[EASE]

Releases the critical section if the process running DSE owns the section.

Use alone.

-REM[OVE]

Terminates any write ownership of the critical section. Use this when the critical section is owned by a process that is nonexistent or is known to no longer be running a GT.M image.

Use alone.

[Caution] Caution

Using CRITICAL -REMOVE when the write owner of a critical section is an active GT.M process may cause structural database damage.

-RES[ET]

Displays the number of times the critical section has been through an online reinitialization.

Using -RESET with -INIT causes an error for processes that are attempting to get the critical section of the region. Under the guidance of FIS, use -RESET -INIT as a way to clear certain types of hangs.

Use only with: -INIT

-S[EIZE]

Seizes the critical section (if available).

  • You can also use SEIZE to temporarily suspend database updates.

  • Subsequently, execute CRITICAL -RELEASE command to restore normal operation.

Examples for CRITICAL

Example:

DSE> critical -OWNER Write critical section owner is process id 4220

This command displays the ID of the process holding the critical section. Note that on catching a process ID on a lightly loaded (or unloaded) system (for example, text environment) is like catching lightening in a bottle. Therefore, you can artificially hold a critical section using the DSE CRIT -SEIZE command in one session and view the owner using a different session.

Dump

Displays blocks, records, or file headers. DUMP is one of the primary DSE examination commands.

The format of the DUMP command is:

D[UMP]  
[
-A[LL]
-B[LOCK]=block_number
-C[OUNT]=count
-F[ILEHEADER]
-G[LO]
-G[VSTATS]
-[NO]C[RIT]
-[NO]H[EADER]
-O[FFSET]=offset
-R[ECORD]=record-number
-U[PDPROC]
-Z[WR]
]

Use the error messages reported by MUPIP INTEG to determine what to DUMP and examine in the database. DUMP also can transfer records to a sequential file for future study and/or for input to MUPIP LOAD (see the section on OPEN). The DUMP command requires specification of an object using either -BLOCK, -HEADER, -RECORD, or -FILEHEADER.

Qualifiers of DUMP

-A[LL]

When used with -FILEHEADER, the -A[LL] qualifier displays additional information on the database most of which is useful for FIS in diagnosing issues. A complete description of all the elements that show up with the DSE DUMP -FILEHEADER -ALL command are beyond the scope of this book.

Meaningful only with: -FILEHEADER

-B[LOCK]=block-number

Specifies the starting block of the dump. For commands without an object qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, (that is, on the first block-oriented command), DSE uses block one (1).

Incompatible with: -ALL, -FILEHEADER and -UPDPROC.

-C[OUNT]=count

Specifies the number of blocks, block headers, or records to DUMP.

Incompatible with: -ALL, -FILEHEADER and -UPDPROC.

-F[ILEHEADER]

Dumps file header information. A DSE dump of a database file header prints a 0x prefix for all fields printed in hexadecimal format. Refer to the "Introduction" section for a description of the file header fields.

Use only with -ALL or -UPDPROC

-G[LO]

Dumps the specified record or blocks into the current output file in Global Output (GO) format. FIS strongly suggests using -ZWR rather than -GLO as the ZWR format handles all possible content values, including some that are problematic with -GLO.[The GLO format is not supported for UTF-8 mode - use the ZWR format with UTF-8 mode.

Incompatible with: -ALL, -FILEHEADER, -UPDPROC and -ZWR.

-G[VSTATS]

Displays the access statistics for global variables and database file(s).

-NO[CRIT]

Allows DSE DUMP to work even if another process is holding a critical section. Since results in this mode may be inconsistent, it should only be used if the critical section mechanism is not operating normally.

-[NO]H[EADER]

Specifies whether the dump of the specified blocks or records is restricted to, or excludes, headers. -HEADER displays only the header, -NOHEADER displays the block or record with the header suppressed. DUMP without the -[NO]HEADER qualifier dumps both the block/record and the header.

By default, DUMP displays all information in a block or record.

Incompatible with: -ALL, -FILEHEADER, -GLO, -UPDPROC and -ZWR.

-O[FFSET]=offset

Specifies the offset, in bytes, of the starting record for the dump. If the offset does not point to the beginning of a record, DSE rounds down to the last valid record start (e.g., DUMP -OFF=10 starts at -OFF=A if that was the beginning of the record containing offset 10).

Incompatible with: -ALL, -FILEHEADER, and -RECORD.

-R[ECORD]=record_number

Specifies the record number of the starting record of the dump. If you try to dump a record number that is larger than the last actual record in the block, a DSE error message provides the number of the last record in the block.

Incompatible with: -ALL, -FILEHEADER, and -OFFSET.

-U[PDPROC]

Displays the helper process parameters with the fileheader elements.

Use only with -FILEHEADER.

-Z[WR]

Dumps the specified record or blocks into the current output file in ZWRITE (ZWR) format.

Incompatible with: -ALL, -GLO, -HEADER and -FILEHEADER.

Examples for DUMP

Example:

DSE> DUMP -FILEHEADER

This command displays an output like the following:

File    /home/jdoe/.fis-gtm/V7.1-002_x86_64/g/gtm.dat
Region  DEFAULT
File            /home/jdoe/.fis-gtm/V7.1-002_x86_64/g/gtm.dat
Region          DEFAULT
Date/Time       12-SEP-2023 17:31:20 [$H = 66729,63080]
  Access method                           BG  Global Buffers                  1024
                                              Block size (in bytes)           4096
  Maximum record size                    256  Starting VBN                    8193
  Maximum key size                        64  Total blocks      0x0000000000000065
  Null subscripts                      NEVER  Free blocks       0x0000000000000062
  Standard Null Collation              FALSE  Free space                0x00000000
  Last Record Backup      0x0000000000000001  Extension Count                  100
  Last Database Backup    0x0000000000000001  Number of local maps               1
  Last Bytestream Backup  0x0000000000000001  Lock space                0x00000028
  In critical section             0x00000000  Timers pending                     0
  Cache freeze id                 0x00000000  Flush timer              00:00:01:00
  Freeze match                    0x00000000  Flush trigger                    960
  Freeze online                        FALSE  Freeze online autorelease      FALSE
  Current transaction     0x0000000000000001  No. of writes/flush                7
  Maximum TN              0xFFFFFFF803FFFFFF  Certified for Upgrade to          V7
  Maximum TN Warn         0xFFFFFFD813FFFFFF  Desired DB Format                 V7
  Master Bitmap Size                    8176  Blocks to Upgrade 0x0000000000000000
  Create in progress                   FALSE  Modified cache blocks              0
  Reference count                          1  Wait Disk                          0
  Journal State                [inactive] ON  Journal Before imaging          TRUE
  Journal Allocation                    2048  Journal Extension               2048
  Journal Buffer Size                   2312  Journal Alignsize               4096
  Journal AutoSwitchLimit            8386560  Journal Epoch Interval           300
  Journal Yield Limit                      8  Journal Sync IO                FALSE
  Journal File: /home/jdoe/.fis-gtm/V7.0-002_x86_64/g/gtm.mjl
  Mutex Hard Spin Count                  128  Mutex Sleep Spin Count           128
  Mutex Queue Slots                     1024  KILLs in progress                  0
  Replication State                      OFF  Region Seqno      0x0000000000000001
  Zqgblmod Seqno          0x0000000000000000  Zqgblmod Trans    0x0000000000000000
  Endian Format                       LITTLE  Commit Wait Spin Count            16
  Database file encrypted              FALSE  Inst Freeze on Error           FALSE
  Spanning Node Absent                  TRUE  Maximum Key Size Assured        TRUE
  Defer allocation                      TRUE  Spin sleep time mask      0x00000000
  Async IO                               OFF  WIP queue cache blocks             0
  DB is auto-created                   FALSE  DB shares gvstats               TRUE
  LOCK shares DB critical section      FALSE  Read Only                        OFF
  Recover interrupted                  FALSE  Full Block Write                   0
  StatsDB Allocation                    2050
  Data Reserved Bytes                      0  Index Reserved Bytes               0

Note that the certain fileheader elements appear depending on the current state of database. For example, if Journaling is not enabled in the database, DSE does not display Journal data element fields.

Example:

$ dse dump -fileheader -updproc

This command displays the fileheader elements along with the following helper process parameters:

Upd reserved area [% global buffers]     50  Avg blks read per 100 records          200
Pre read trigger factor [% upd rsrvd]    50  Upd writer trigger [%flshTrgr]          33

For more information, refer to the fileheader elements section in GT.M Database Structure(GDS).

EValuate

Translates a hexadecimal number to decimal, and vice versa.

The format of the EVALUATE command is:

EV[ALUATE]  
[
-D[ECIMAL]
-H[EXADECIMAL]
-N[UMBER]=number
]

The -DECIMAL and -HEXADECIMAL qualifiers specify the input base for the number. The -NUMBER qualifier is mandatory. By default, EVALUATE treats the number as having a hexadecimal base.

Qualifiers of Evaluate

-D[ECIMAL]

Specifies that the input number has a decimal base.

Incompatible with: -HEXADECIMAL .

-H[EXADECIMAL]

Specifies that the input number has a hexadecimal base.

Incompatible with: -DECIMAL

-N[UMBER]=number

Specifies the number to evaluate. Required.

Examples for EVALUATE

Example:

DSE> evaluate -number=10 -decimal
Hex:  A   Dec:  10

This command displays the hexadecimal equivalent of decimal number 10.

Example:

DSE> evaluate -number=10 -hexadecimal
Hex:  10   Dec:  16

This command displays the decimal equivalent of hexadecimal 10.

Example:

$ dse evaluate -number=10
Hex:  10   Dec:  16

This command displays the decimal equivalent of Hexadecimal 10. Note that if you do not specify an qualifier with -NAME, then EVALUATE assumes Hexadecimal input.

EXit

The EXIT command ends a DSE session.

The format of the EXIT command is:

EX[IT]

The EXIT command has no qualifiers.

Find

Locates a given block or region. The format of the FIND command is:

F[IND]  
[
-B[LOCK]=block-number
-E[XHAUSTIVE]
-F[REEBLOCK] -H[INT]
-K[EY]=key
-[NO]C[RIT]
-R[EGION][=region]
-SI[BLINGS]
-ST[ATS]
]
  • At the beginning of a DSE session, use the FIND -REGION command to select the target region.

  • The FIND command, except when used with the -FREEBLOCK and -REGION qualifiers, uses the index tree to locate blocks. FIND can locate blocks only within the index tree structure. If you need to locate keys independent of their attachment to the tree, use the RANGE command.

Qualifiers of FIND

-B[LOCK]=block_number

Specifies the block to find.

On commands without the -BLOCK= qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

Incompatible with: -KEY, -REGION

-E[XHAUSTIVE]

Searches the entire index structure for the desired path or siblings.

  • FIND -EXHAUSTIVE locates blocks that are in the tree but not indexed correctly.

  • FIND -EXHAUSTIVE locates all paths to a "doubly allocated" block.

[Note] Note

A doubly allocated block may cause inappropriate mingling of data. As long as no KILLs occur, double allocation may not cause permanent loss of additional data. However, it may cause the application programs to generate errors and/or inappropriate results. When a block is doubly allocated, a KILL may remove data outside its proper scope. See "Maintaining Database Integrity Chapter" for more information on repairing doubly allocated blocks.

Incompatible with: -KEY, -REGION, -FREEBLOCK

-F[REEBLOCK]

Finds the nearest free block to the block specified by -HINT. FREEBLOCK accepts bit maps as starting or ending points.

  • The -FREEBLOCK qualifier is incompatible with all other qualifiers except -BLOCK and -HINT.

  • The -HINT qualifier is required with the -FREEBLOCK qualifier.

  • FIND -FREEBLOCK relies on the bitmaps to locate its target, so be sure to fix any blocks incorrectly marked "FREE" before using this command. See MAP -BUSY for more information on fixing incorrectly marked free errors.

Required with -HINT; compatible with -BLOCK and [NO]CRIT.

-H[INT]=block_number

Designates the starting point of a -FREEBLOCK search.

FIND -FREE -HINT locates the "closest" free block to the hint. This provides a tool for locating blocks to add to the B-tree, or to hold block copies created with SAVE that would otherwise be lost when DSE exits. FIND -FREE relies on the bitmaps to locate its target, so be sure to fix any blocks incorrectly marked "FREE" before using this command.

Required with: -FREEBLOCK; compatible with -BLOCK and [NO]CRIT.

-K[EY]=key

Searches the database for the block containing the specified key or if the key does not exist, the block that would contain it, if it existed.

  • Enclose an M-style key in quotation marks (" "). FIND -KEY is useful in locating properly indexed keys. The -KEY qualifier is incompatible with all other qualifiers.

  • FIND -KEY= uses the index to locate the level zero (0) block , or data block, containing the key. If the key does not exist, it uses the index to locate the block in which it would reside. Note that FIND only works with the index as currently composed. In other words, it cannot FIND the "right" place, only the place pointed to by the index at the time the command is issued. These two locations should be, and may well be, the same; however, remind yourself to search for, understand and take into account all information describing any current database integrity issues.

  • DSE accepts ^#t as a valid global name when specifying a key.

Compatible only with [NO]CRIT.

-[NO]C[RIT]

Allows FIND to work even if another process is holding a critical section.

As results in this mode may be inconsistent, it should only be used if the critical section mechanism is not operating normally

-R[EGION][=region]

Switches to the named Global Directory region.

-REGION without a specified region, or -REGION="*", displays all existing regions in the database.

Use Alone.

-SI[BLINGS]

Displays the block number of the specified block and its logical siblings in hexadecimal format.

The logical siblings are the blocks, if any, that logically exist to the right and left of the given block in the database tree structure.

Incompatible with: -FREEBLOCK, -HINT, -KEY, -REGION

-ST[ATS]

Switches to the named Global Directory shadow for the region's shared gvstats.

Compatible only with R[EGION].

Examples for FIND

Example:

DSE> find -exhaustive -block=180
Directory path
Path--blk:off
1:10 2:1E
Global paths
Path--blk:off
6:51 1A4:249 180

This command locates block 180 by looking through the B-tree index for any pointer to the block. This command finds even those blocks that are connected to the tree but the first key in the block does not match the index path.

Example:

DSE> find -free -hint=180
Next free block is D8F.

This command locates the "closest" free block to block 180.

You can use this command as a tool for locating blocks to add to the B-tree, or to hold block copies created with SAVE that would otherwise be lost when DSE exits.

Example:

DSE>find -key="^biggbl(1)"

This command locates the key ^biggbl(1) in the database.

Example:

DSE> find -freeblock -hint=232

This commands starts to search for free block after block 232.

Example:

DSE> FIND -FREEBLOCK -HINT=232 -NOCRIT

This command searches for freeblocks after block 232 even if another process is holding a critical section.

Example:

DSE> find -sibling -block=10

This command operates like FIND -BLOCK; however it reports the numbers of the blocks that logically fall before and after block 180 on the same level. This command produces an output like the following:

Left sibling    Current block   Right sibling
        0x0000000F      0x00000010      0x00000011

Help

The HELP command explains DSE commands. The format of the HELP command is:

-H[ELP] [help topic]

Integrit

Checks the internal consistency of a single non-bitmap block. INTEGRIT reports errors in hexadecimal notation.

The format of the INTEGRIT command is:

I[NTEGRIT] -B[LOCK]=block-number
[Note] Note

Unlike MUPIP INTEG, this command only detects errors internal to a block and cannot detect errors such as indices incorrectly pointing to another block. For information on the utility that checks multiple blocks, refer to the “INTEG ” of the General Database Management chapter.

Qualifiers of Integrit

-B[LOCK]=block_number

Specifies the block for DSE to check. On commands with no -BLOCK qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

-NO[CRIT]

Allows DSE INTEG to work even if another process is holding a critical section. Since results in this mode may be inconsistent, it should only be used if the critical section mechanism is not operating normally.

Maps

Examines or updates bitmaps. The format of the MAPS command is:

M[APS] 
[
-BL[OCK]=block-number
-BU[SY]
-F[REE]
-M[ASTER]
-R[ESTORE_ALL]
]

MAPS can flag blocks as being either -BUSY or -FREE. The -MASTER qualifier reflects the current status of a local bitmap back into the master map. The -RESTORE_ALL qualifier rebuilds all maps and should be used with caution since it can destroy important information.

By default, MAPS shows the status of the bitmap for the specified block.

Qualifiers for MAP

-BL[OCK]=block_number

Specifies the target block for MAPS. The -BLOCK qualifier is incompatible with the -RESTORE_ALL qualifier.

On commands with no -BLOCK= or -RESTORE_ALL qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

Incompatible with: -RESTORE_ALL

-BU[SY]

Marks the current block as busy in the block's local map and appropriately updates the master bitmap. BUSY accepts bit map blocks.

Compatible only with: -BLOCK

-F[REE]

Marks the current block as free in the block's local map and appropriately updates the master bitmap.

Compatible only with: -BLOCK

-M[ASTER]

Sets the bit in the master bitmap associated with the current block's local map according to whether or not that local map is full. MASTER accepts bit map blocks.

Use only with: -BLOCK.

-R[ESTORE_ALL]

Sets all local bitmaps and the master bitmap to reflect the blocks used in the database file.

Use -RESTORE_ALL only if the database contents are known to be correct, but a large number of the bitmaps require correction.

[Caution] Caution

The -RESTORE_ALL qualifier rebuilds all maps and should be used with a great deal of caution as it can destroy important information.

Use alone.

Examples

Example:

DSE> MAPS -BLOCK=20 -FREE

This command flags block 20 as free. A sample DSE DUMP output block 0 is as follows:

Block 0  Size 90  Level -1  TN 10B76A V7   Master Status: Free Space
                Low order                         High order
Block        0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       20: |  :XXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       40: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       60: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       80: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       A0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       C0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block       E0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      100: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      120: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      140: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      160: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      180: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      1A0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      1C0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
Block      1E0: |  XXXXXXXX  XXXXXXXX  XXXXXXXX  XXXXXXXX  |
'X' == BUSY  '.' == FREE  ':' == REUSABLE  '?' == CORRUPT

Note that BLOCK 20 is marked as REUSABLE, which means FREE but in need of a before-image journal record.

Example:

DSE> maps -block=20 -busy

This command marks block 20 as busy. A sample DSE DUMP output of block 0 is as follows:

Block 0  Size 90  Level -1  TN 1 V7   Master Status: Free Space
                Low order                         High order
Block        0: |  XXX.....  ........  ........  ........  |
Block       20: |  X.......  ........  ........  ........  |
Block       40: |  ........  ........  ........  ........  |
Block       60: |  ........  ........  ........  ........  |
Block       80: |  ........  ........  ........  ........  |
Block       A0: |  ........  ........  ........  ........  |
Block       C0: |  ........  ........  ........  ........  |
Block       E0: |  ........  ........  ........  ........  |
Block      100: |  ........  ........  ........  ........  |
Block      120: |  ........  ........  ........  ........  |
Block      140: |  ........  ........  ........  ........  |
Block      160: |  ........  ........  ........  ........  |
Block      180: |  ........  ........  ........  ........  |
Block      1A0: |  ........  ........  ........  ........  |
Block      1C0: |  ........  ........  ........  ........  |
Block      1E0: |  ........  ........  ........  ........  |
'X' == BUSY  '.' == FREE  ':' == REUSABLE  '?' == CORRUPT

Note that the BLOCK 20 is marked as BUSY.

OPen

Use the OPEN command to open a file for sequential output of global variable data. The format of the OPEN command is:

OP[EN] F[ILE]=file
  • OPEN a file to which you want to "dump" information.

  • If an OPEN command does not have a -FILE qualifier, DSE reports the name of the current output file.

Qualifiers for OPEN

-F[ILE]=file-name

Specifies the file to open.

Examples for OPEN

Example:

DSE> OPEN
Current output file:  var.out

This command displays the current output file. In this case, the output file is var.out.

Example:

DSE> OPEN -FILE=var1.out

The command OPEN -FILE=var1.out sets the output file to var1.out.

OVerwrite

Overwrites the specified string on the given offset in the current block. Use extreme caution when using this command.

The format of the OVERWRITE command is:

OV[ERWRITE] 
[
-D[ATA]=string
-O[FFSET]=offset
]

Qualifiers for OVERWRITE

-B[LOCK]=block number

Directs DSE to OVERWRITE a specific block. If no block number is specified, the default is the current block.

-D[ATA]=string

Specifies the data to be written. Use quotation marks around the string and escape codes of the form \a or \ab, where "a" and "b" are hexadecimal digits representing non-printing characters. \\ translates to a single backslash.

-O[FFSET]=offset

Specifies the offset in the current block where the overwrite should begin.

Examples for Overwrite

Example:

DSE>overwrite -block=31 -data="Malvern" -offset=CA

This command overwrites the data at the specified location.

Page

Sends one form feed to the output device. Use PAGE to add form feeds to a dump file, making the hard copy file easier to read. If you plan to use the dump file with MUPIP LOAD, do not use PAGE.

The format of the PAGE command is:

P[AGE]

The PAGE command has no qualifiers.

RAnge

The RANGE command finds all blocks in the database whose first key falls in the specified range of keys. The RANGE command may take a very long time unless the range specified by -FROM and -TO is small. Use FIND -KEY and/or FIND -KEY -EXHAUSTIVE first to quickly determine whether the key appears in the index tree.

The format of the RANGE command is:

RA[NGE] 
[
-F[ROM]=block-number
-T[O]=block-number
-I[NDEX]
-LOS[T]
-[NO]C[RIT]
-[NO]BU[SY]
-S[TAR]
-LOW[ER]=key
-U[PPER]=key                
]

Qualifiers of RANGE

-F[ROM]=block_number

Specifies a starting block number for the range search. DSE RANGE accept bit maps as starting or ending points.

By default, RANGE starts processing at the beginning of the file.

-T[O]=block-number

Specifies an ending block number for the range search. DSE RANGE accept bit maps as starting or ending points. By default, RANGE stops processing at the end of the file.

-I[NDEX]

Restricts a search to index blocks.

-LOS[T]=block_number

Restricts a search to blocks not found by a FIND -BLOCK.

-LOW[ER]=key

Specifies the lower bound for the key range.

-[NO]BU[SY]=busy/free

Restricts a search to either BUSY or FREE blocks.

-[NO]C[RIT]

Allows DSE RANGE to work even if another process is holding a critical section. Since results in this mode may be inconsistent, it should only be used if the critical section mechanism is not operating normally.

-S[TAR]

Includes index blocks that contain a single star key.

-U[PPER]=key

Specifies the upper bound for the key range.

Examples for RANGE

Example:

DSE> range -lower="^abcdefgh" -upper="^abcdefghi" -from=A -to=CC

This command searches for a specified keys between block 10 and block 204. Note that the range (between FROM and TO) of blocks must be valid blocks specified in hexadecimal.

Example:

DSE> range -lower="^abcdefgh" -upper="^abcdefghi" -from=A -to=CC -noindex

This command searches only data blocks for the specified keys between block 10 and block 204.

Example:

DSE> range -lower="^abcdefgh" -upper="^abcdefghi" -from=A -to=CC -index

This command searches only index blocks for the specified keys between block 10 and block 204.

Example:

DSE> range -lower="^abcdefgh" -upper="^abcdefghi" -lost

This command includes lost blocks while searching for the specified keys and reports only blocks which are not currently indexed.

Example:

DSE> range -lower="^Fruits(15)" -upper="^Fruits(877)" -from=A -to=F
Blocks in the specified key range:
Block: 0000000A Level: 0
Block: 0000000B Level: 0
Block: 0000000C Level: 0
Block: 0000000D Level: 0
Block: 0000000E Level: 0
Block: 0000000F Level: 0
Found 6 blocks

This command search for keys between ^Fruits(15) and ^Fruits(877).

REMove

Removes one or more records or a save buffer.

The format of the REMOVE command is:

REM[OVE]
[
-B[LOCK]=block-number
-C[OUNT]=count
-O[FFSET]=offset
-R[ECORD]=record-number
-V[ERSION]=version-number
]

The version number is specified in decimal.

Qualifiers of REMOVE

-B[LOCK]=block_number

Specifies the block associated with the record or buffer being deleted.

On commands with no -BLOCK= qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

BLOCK accepts blocks higher than the current database size because they deal with set of saved block copies rather than the database and there are situations where a saved block may be outside the current database size (for example, due to a concurrent MUPIP REORG -TRUNCATE).

-C[OUNT]=count

Specifies the number of records to remove.

By default, REMOVE deletes a single record.

Incompatible with: -VERSION

-O[FFSET]=offset

Specifies the offset (in bytes) of the record to be removed. If the offset does not point to the beginning of a record, DSE rounds down to the beginning of the record containing the offset (for example, REMOVE -OFF=10 starts at OFF=A if that was the last prior record boundry).

Incompatible with: -VERSION, -RECORD

-R[ECORD]=record_number

Specifies the number that identifies the record to remove. The -RECORD qualifier is incompatible with the -OFFSET and -VERSION qualifiers.

Incompatible with: -VERSION, -OFFSET

-V[ERSION]=version_number

Specifies the version number, in decimal, of the save buffer to remove. If there are more than one version of a block, -VERSION is required; otherwise REMOVE works on that sole version. -VERSION is incompatible with all qualifiers except -BLOCK.

If there is only one version of the specified -BLOCK= block in the current region, DSE REMOVE defaults to that version.

Use only with: -BLOCK; decimal

REStore

The RESTORE command restores saved versions of blocks.

RES[TORE]   
[
-B[LOCK]=block-number
-F[ROM]=from
-R[EGION]=region
-V[ERSION]=version-number  
]

The version number is specified in decimal.

Qualifiers of RESTORE

-B[LOCK]=block_number

Specifies the block to restore.

For commands with no -BLOCK= qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, (i.e., on the first block-oriented command), DSE uses block one (1).

BLOCK accepts blocks higher than the current database size because it deal with set of saved block copies rather than the database and there are situations where a saved block may be outside the current database size (for example, due to a concurrent MUPIP REORG -TRUNCATE).

-F[ROM]=block_number

Specifies the block number of the SAVE buffer to restore.

DSE restores the block specified with -BLOCK qualifier with the block specified by the -FROM qualifier. If there is only one version of the specified -FROM= block, DSE RESTORE defaults to that version and it always restores the original block transaction number.

By default, RESTORE uses the target block number as the -FROM block number.

-R[EGION]=region

Specifies the region of the saved buffer to restore.

By default, RESTORE uses SAVE buffers from the current region.

-V[ERSION]=version_number

Specifies the decimal version number of the block to restore. The version number is required.

SAve

The SAVE command preserves versions of blocks, or displays a listing of saved versions for the current DSE session. SAVE can preserve 128 versions. Saved information is lost when DSE EXITs.

Use with the RESTORE command to move SAVEd blocks to a permanent location, and as a safety feature use SAVE to retain copies of database blocks before changing them.

The format of the SAVE command is:

SA[VE] 
[
-B[LOCK]=block-number
-C[OMMENT]=string
-L[IST]
-[NO]C[RIT]
]

Qualifiers of SAVE

-B[LOCK]=block_number

Specifies the block to restore.

On commands with no -BLOCK= qualifier, DSE uses the last block handled by a DSE operation. When no block has been accessed, that is, on the first block-oriented command, DSE uses block one (1).

-C[OMMENT]=string

Specifies a comment to save with the block. Enclose the comment in quotation marks (" ").

Incompatible with: -LIST

-L[IST]

Lists saved versions of specified blocks. The -LIST qualifier is incompatible with the -COMMENT qualifier.

By default, SAVE -LIST provides a directory of all SAVEd blocks.

LIST may display blocks higher than the current database size because it deals with set of saved block copies rather than the database and there are situations where a saved block may be outside the current database size (for example, due to a concurrent MUPIP REORG -TRUNCATE);

Incompatible with: -COMMENT

-[NO]C[RIT]

Allows DSE SAVE to work even if another process is holding a critical section. Since results in this mode may be inconsistent, it should only be used if the critical section mechanism is not operating normally.

SHift

Use the SHIFT command to shift data in a block, filling the block with zeros, or shortening the block. The format of the SHIFT command is:

SH[IFT]  
[
-B[ACKWARD]=b_shift
-BL[OCK]=block_number
-F[ORWARD]=f_shift
-O[FFSET]=offset
]

b_shift must always be less than or equal to offset. This means that DSE SHIFT in the backward direction is restricted to the maximum of OFFSET number of bytes. This ensures that the shift does not cross block boundaries, either intentionally or unintentionally.

Qualifiers of SHIFT

-B[ACKWARD]=shift

Specifies the number of bytes to shift data in the direction of the block header.

Incompatible with: -FORWARD

-BL[OCK]=block_number

Specifies the block number to perform the DSE SHIFT.

-F[ORWARD]=shift

Specifies the number of bytes to shift data toward the end of the block.

Incompatible with: -BACKWARD

-O[FFSET]=offset

Specifies the starting offset, in bytes, of the portion of the block to shift.

SPawn

Use the SPAWN command to fork a child process for access to the shell without terminating the current DSE environment.

The format of the SPAWN command is:

SP[AWN] [shell-command]
  • The SPAWN command accepts an optional command string for execution by the spawned sub-process. If the SPAWN has no command string parameter, the created sub-process issues a shell prompt and accepts any legal shell command. To terminate the sub-process, use the shell logout command.

  • The SPAWN command has no qualifiers.

  • DSE SPAWN works with an argument. If the argument contains spaces, enclose it with quotes.

The SPAWN command has no qualifiers.

DSE SPAWN works with an argument. If the argument contains spaces, enclose it with quotes.

Examples of SPAWN

Example:

DSE> SPAWN "mumps -run ^GDE"

This command suspends a DSE session and executes the shell command mumps -run ^GDE.

Wcinit

Use the WCINIT command to reinitialize the global buffers of the current region. Because it cleans out the cache, the WCINIT command should not be used except under the guidance of FIS.

[Caution] Caution

A WCINIT command issued while normal database operations are in progress can cause catastrophic damage to the database.

The format of the WCINIT command is:

W[CINIT]
  • The WCINIT command has no qualifiers.

  • When you issue the WCINIT command, DSE issues the CONFIRMATION: prompt. You must verify the WCINIT command by responding with "YES."

    If you do not confirm the WCINIT, DSE issues the message:

     No action taken, enter yes at the CONFIRMATION prompt to initialize global buffers.
  • WCINIT operations are more safely performed by MUPIP RUNDOWN. Use this command only under instructions from FIS.