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

-FI[LEHEADER]

Enables modification of specific fields in the file header. The -FILEHEADER qualifier is incompatible with the -BLOCK and all qualifiers related to -BLOCK (that is -BSIZ, -CMPC, -LEVEL, -OFFSET, -RECORD, -RSIZ, and -TN qualifiers).

-BLK[_SIZE]=block_size

Changes the decimal block size field of the current file.

The block size cannot be changed to an arbitrary value. It always rounds the block size to the next higher multiple of 512, because database block sizes must always be a multiple of 512.

Use the CHANGE -BLK_SIZE qualifier only upon receiving instructions from Fidelity and only in conjunction with the -FILEHEADER qualifier.

-BLO[CKS_FREE]=free blocks

Changes the free blocks field of the current file. Use the -BLOCK_FREE qualifier only in conjunction with the -FILEHEADER qualifier.

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

-CO[RRUPT_FILE]=value

Sets the file-corrupt field in the file header. Possible values are: T[RUE] or F[ALSE]. Use the -CORRUPT_FILE qualifier only in conjunction with the -FILEHEADER qualifier.

-CU[RRENT_TN]=transaction_number

Changes the current transaction number for the current region. It also places a transaction number in a block header. This qualifier has implications only for MUPIP BACKUP -INCREMENTAL. Raising the -CURRENT_TN can correct "block transaction number too large" errors .

-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 is centi-seconds (hundredths of a second). For example, to change the flush time interval to a second, delta_time would be 100. To change it to 30 minutes, delta_time would be 180,000 (30*60*100). Valid values for the qualifier are one to 360,000 (an hour).

Use the CHANGE -FLUSH_TIME qualifier only upon receiving instructions from Fidelity and only in conjunction with the -FILEHEADER qualifier.

-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 the -FREEZE qualifier only in conjunction with the -FILEHEADER qualifier.

For information about a preferred method of manipulating FREEZE, refer to the MUPIP FREEZE section of the "MUPIP" chapter.

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

-K[EY_MAX_SIZE]=key_max_size

Changes the decimal value for the maximum allowable key size. Use the -KEY_MAX_SIZE qualifier only in conjunction with the -FILEHEADER qualifier. 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 the "Global Directory Editor" chapter.

-N[ULL_SUBSCRIPTS]=value

Sets the acceptability of null subscripts in database keys. Possible values are: T[RUE] or F[ALSE]. Prohibiting null subscripts can restrict access to existing data and cause GT.M to report errors.

DSE rejects null subscripts for the -KEY qualifier for various commands if they are disabled by the NULLSUBSCRIPTS flag in the file header.

-Q[UANTUM_INTERVAL][=delta_time]

Changes the amount of time a single system holds control of writes to the database file. The time entered must be between 0 and 1 hour. The defualt value is one second for BG and 30 seconds for MM.

This qualifier applies only to clustered databases. Input is interpreted as decimal. A -QUANTUM_INTERVAL with no value resets the -QUANTUM_INTERVAL to the default value (one second).

Use the CHANGE-QUANTUM_INTERVAL qualifier only upon receving instructions from Fidelity and only in conjunction with the -FILEHEADER qualifier.

-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 the "Global Directory Editor" chapter.

-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.

-TI[MERS_PENDING]=timers_pending

Sets a field that tracks the 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 Fidelity, and then only in conjunction with the -FILEHEADER qualifier.

-TO[TAL_BLKS]=total_blocks

Changes the total blocks field of the current file. Use the -TOTAL_BLKS qualifier only in conjunction with the -FILEHEADER qualifier.

-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 Fidelity, and only in conjunction with the -FILEHEADER qualifier.

-WR[ITES_PER_FLUSH]=writes_per_flush

Sets the decimal number of blocks to write in each flush.

Use the CHANGE -WRITES_PER_FLUSH qualifier only upon receiving instructions from Fidelity, and then only in conjunction with the -FILEHEADER qualifier.