HP 3000 Manuals HP 3000 Manuals
Appendix H TurboIMAGE/XL versus TurboIMAGE/V
Overview
TurboIMAGE/XL is available on the HP 3000 Series 900. This database
management system is very similar to TurboIMAGE/V. However, some
differences exist due to the architecture of the 900 series and the
MPE/iX features of which TurboIMAGE/XL takes advantage. Specific
TurboIMAGE/XL differences are listed here:
* Transaction Management (XM), an internal MPE/iX service, is used
to do the following:
* Ensure intrinsic level physical consistency of the database
as a default unless the AUTODEFER option is enabled.
Incomplete intrinsics will be backed out and not reapplied.
This performs the same functionality as Intrinsic Level
Recovery (ILR) on MPE V.
* Guarantee via Intrinsic Level Recovery (ILR) that not more
than one DBDELETE or DBPUT per process will be lost. ILR
should be disabled on TurboIMAGE/XL.
* Recover transactions via dynamic roll-back recovery while
other database activity is occurring.
* Mapped files are used instead of extra data segments for run-time
control blocks. Another control block, the Database User Local
Index (DBUX), has been added.
* The maximum number of DBOPENs per process is 127 (63 per database)
depending on the availability of system resources.
* Some status area information returned by TurboIMAGE/XL library
procedures is different for MPE/iX applications because of the
change from 16-bit to 32-bit architecture.
* Some information returned by DBINFO mode 402 is different because
of the change in how ILR is implemented.
* For roll-back recovery: If logging to disk, the user log file and
the database must reside in the same volume set. If logging to
tape, the database must be in the system volume set.
* DBSTORE has a TRANSPORT option in the INFO=string for moving
TurboIMAGE/XL databases to MPE V.
* Applications can change the values of detail data set search and
sort items via the critical item update (CIUPDATE) option.
* Third-party indexing software that works in conjunction with
TurboIMAGE/XL provides the capability to do generic key searches,
multiple keyword retrievals, and sorted sequential searches on any
database that is enabled for third-party indexing.
The rest of this appendix discusses the major differences in detail.
They include the following:
* Intrinsic Level Recovery
* Control Blocks
* Status Area
* Moving from MPE/iX to MPE V
TurboIMAGE/XL differences are summarized in Table H-1 .
Moving to TurboIMAGE/XL
To move a database from MPE V to MPE/iX, you need to perform the
following tasks:
1. Disable both ILR and roll-back recovery (use the >>DISABLE command
of DBUTIL).
2. On MPE V, store the database with DBSTORE (or use the MPE V STORE
command).
3. On MPE/iX, restore the database with DBRESTOR (or use the MPE/iX
RESTORE command).
For more detailed migration information, refer to the Migration Process
Guide.
Table H-1. TurboIMAGE/XL Differences
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- Area Affected - Changes/Additions -
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- Data Set Size - - The maximum data set size is 4 gigabytes. -
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| DBEXPLAIN | - Information for DBEXPLAIN is stored in the Database |
| | User Local Control Block (DBU). |
| | - Calls to DBEXPLAIN must be made immediately after |
| | receiving an error status. |
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| DBOPEN | - A maximum of 127 DBOPENs is allowed per process (63 |
| | per database). |
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| DBSTORE Command | - A TRANSPORT option has been added for use when moving |
| | a TurboIMAGE/XL database to MPE V. |
| | - The move from MPE/iX to MPE V may not be possible if |
| | data sets are larger than the MPE V file size limit. |
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| DBUPDATE | - If the critical item update (CIUPDATE) option of |
| | DBUTIL is set to ON or ALLOWED for a database, |
| | applications can use DBUPDATE to change the values of |
| | detail data set search and sort items. |
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| Dynamic Roll-Back Recovery | - Physical integrity of the database is provided by |
| | MPE/iX Transaction Management (XM) logging, by |
| | default. |
| | - Dynamic roll-back works in conjunction with XM and |
| | ensures the logical integrity of the database after a |
| | program abort or system failure. |
| | - Transactions are rolled back online while other |
| | database activity is occurring. |
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| Intrinsic Level Recovery | - Physical consistency of the database is provided by |
| | MPE/iX Transaction Management as a default. |
| | - The ILR log file is replaced by the MPE/iX Transaction |
| | Management log file. |
| | - Incomplete intrinsics are backed out and will not be |
| | reapplied. |
- - - DBUPDATE is included in the recovery. -
| | - DBINFO mode 402 no longer contains ILR recovery |
| | information. |
| | - To move between MPE V and MPE/iX, disable ILR and |
| | roll-back recovery. |
- - - ILR is not required for roll-back recovery. -
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- Remote Database Access - - Only NS/3000 is supported on MPE/iX. -
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Table H-1. TurboIMAGE/XL Differences (cont.)
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- Area Affected - Changes/Additions -
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- Roll-Back Recovery - - ILR is not required. -
| | - If logging to disk,the user log file and the database |
| | must be in the same volume set. If logging to tape, |
| | the database must be on the system volume set. |
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- Run-Time Control Blocks - - Mapped files are used for control blocks. -
| | - A control block called the Database User Local Index |
| | (DBUX), which is unique to a process, has been added. |
| | It contains dynamic roll-back information, as well as |
| | the addresses and file numbers of all the DBUs and |
| | DBRs belonging to a specific process. |
| | - The database ID number returned by DBOPEN now serves |
| | as an index into the DBUX. |
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| Status Area | - Status elements 5, 7, 8, and 10 are modified for |
| | Native Mode (NM) applications. |
| | - For condition code -9, elements 2, 3, and 4 have a new |
| | format for both Compatibility Mode (CM) and NM |
| | applications. |
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| Third-Party Indexing | - If your database is configured for indexing using a |
| | supported third-party product, you have the capability |
| | to do generic key searches, multiple keyword |
| | retrievals, and sorted sequential searches on that |
| | database using the DBFIND and DBGET intrinsics. Refer |
| | to your third-party vendor documentation for details. |
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- TURBO Trace and Profiler - - TURBO Trace and Profiler are not available. -
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