TurboIMAGE/XL Database Management System Reference Manual (30391-90012)
Table Of Contents
- 1 Introduction
- 2 Database Structure and Protection
- 3 Defining a Database
- 4 Using the Database
- 5 TurboIMAGE/XL Library Procedures
- Using TurboIMAGE/XL Intrinsics
- DBBEGIN
- DBCLOSE
- DBCONTROL
- DBDELETE
- DBEND
- DBERROR
- DBEXPLAIN
- DBFIND
- DBGET
- DBINFO
- INTRINSIC NUMBER 402
- Syntax
- Parameters
- Discussion
- Mode 101: Item Number
- Mode 102: Item Name
- Mode 103: Items in Database
- Mode 104: Items in Data Set
- Mode 113: BTREEMODE1 and Wildcard Character
- Mode 201: Set Number
- Mode 202: Set Name
- Mode 203: Sets in Database
- Mode 204: Sets with Item
- Mode 205: Set Capacity
- Mode 206: Number of Data Set Chunks
- Mode 207: Size of Data Set Chunks
- Mode 208: Primary and Actual Capacity
- Mode 209: B-Tree Attachment
- Mode 301: Paths
- Mode 302: Key or Search Item
- Mode 401: Logging
- Mode 402: ILR
- Mode 403: Dynamic Roll-Back
- Mode 404: Logging Subsystem Information
- Mode 406: Database Information
- Mode 501: Subsystem Access
- Mode 502: Critical Item Update
- Modes 8nn: Third-Party Indexing
- Mode 901: Language
- DBLOCK
- DBMEMO
- DBOPEN
- DBPUT
- DBUNLOCK
- DBUPDATE
- DBXBEGIN
- DBXEND
- DBXUNDO
- 6 Host Language Access
- Model Program
- ORDERS Database Model Program
- Main Body of Program
- Opening the Database
- Retrieving All the Records on a Chain (with Item Level Locking)
- Retrieving a Data Entry Using a Record Number
- Retrieving Master Data Using a Key Value
- Retrieving Data Serially (with Set Level Locking)
- Adding an Entry
- Updating an Entry
- Deleting an Entry
- Rewinding a Data Set
- Obtaining Database Information
- Obtaining Error Messages and Explanations
- Closing the Database
- C
- COBOL II
- Defining Data Types, Variables, and Intrinsics
- Main Body of Program
- Opening the Database
- Retrieving All the Records on a Chain (with Item Level Locking)
- Retrieving a Data Entry Using a Record Number
- Retrieving Master Data Using a Key Value
- Retrieving Data Serially (with Set Level Locking)
- Adding an Entry
- Updating an Entry
- Deleting an Entry
- Rewinding a Data Set
- Obtaining Database Information
- Obtaining Error Messages and Explanations
- Closing the Database
- FORTRAN 77
- Pascal
- RPG
- 7 Logging and Recovery
- Database Utilities Used in Logging and Recovery
- Recovery Options
- Logical Transactions
- Dynamic Roll-Back Recovery
- Intrinsic Level Recovery
- Logging Preparation
- Step 1--Checking MPE/iX Logging Configuration
- Step 2--Acquiring Logging Capability
- Step 3--Logging to Tape or Disk
- Step 4--Building a Log File for Logging to Disk
- Step 5--Creating the Log Identifier
- Step 6--Setting the Log Identifier
- Step 7--Setting Flags for the Database Backup Copy
- Step 8--Making a Database Backup Copy
- TurboSTORE/iX 7x24 True-Online Backup
- Logging Status
- Logging Maintenance
- Roll-Forward Recovery
- Roll-Back Recovery
- DBRECOV Commands Used with Roll-Forward and Roll-Back Recovery
- Recovery Tables
- Post-Recovery Options
- The Mirror Database
- 8 Using the Database Utilities
- Restructuring the Database with TurboIMAGE/XL Utilities
- Summary of Utility Routines
- Utility Program Operation
- DBLOAD
- DBRECOV
- >CONTROL
- >EXIT
- >FILE
- >RECOVER
- >ROLLBACK
- >RUN
- DBRESTOR
- DBSTORE
- DBUNLOAD
- DBUTIL
- >>ACTIVATE
- >>ADDINDEX
- >>CREATE
- >>DEACTIVATE
- >>DETACH
- >>DISABLE
- >>DROPINDEX
- >>ENABLE
- >>ERASE
- >>EXIT
- >>HELP
- >>MOVE
- >>PURGE
- >>REBUILDINDEX
- >>REDO
- >>RELEASE
- >>SECURE
- >>SET
- >>SHOW
- Syntax
- Parameters
- Example (Show Users)
- Example Discussion
- Example (Show All)
- Example Discussion
- Example (Show Capacity)
- Format of Show Device List
- Example (Show Device)
- Format of Show Indices
- Example (Show Indices)
- Format of Show Locks List
- Example 1 (Show Locks)
- Example 1 Discussion
- Example 2 (Show Locks)
- Example 2 Discussion
- >>VERIFY
- 9 Using a Remote Database
- 10 Internal Structures and Techniques
- 11 B-Tree Indices
- A Error Messages
- B Results of Multiple Access
- C Database Design Considerations
- D Multiple Calls to DBLOCK
- E TurboIMAGE/XL Log Record Formats
- F MPE/iX Log Record Formats
- G Recovery and Logging Quick Reference
- H TurboIMAGE/XL versus TurboIMAGE/V
350 Chapter7
Logging and Recovery
Roll-Forward Recovery
Performing Roll-Forward Recovery
To complete the transaction roll-forward process following a hard system failure, perform
the following steps:
1. Following a start recovery operation to bring up the system, locate the applicable log
file medium to be used for roll-forward recovery.
If logging to tape, the correct tape needs to be mounted. If using the MPE/iX CHANGELOG
feature and there are multiple log file tapes, this will be the first tape in the series if
DBSTORE was used. If TurboSTORE/iX 7x24 True-Online Backup (with
ONLINE=START or ONLINE=END option) was used to backup the database and
AUTO option is used, this may not be the first file in the series. If logging to disk,
TurboIMAGE/XL automatically locates the first log file in the given logging cycle after
checking for the logid in the root file. When TurboSTORE/iX 7x24 True-Online Backup
(with ONLINE=START or ONLINE=END option) is used, necessary information such
as the log file name in use, log file record numbers, date, and time of backup is recorded
in the root file before backup. When the database is restored from this backup, the SHOW
database
ALL command of DBUTIL displays this information.
Note that the system boot-up process writes a crash record to the last volume of the
user log set. If a start recovery operation is not performed, this will not occur, causing
DBRECOV to issue a warning.
2. Check your backup listings to see when your database was last stored. If time permits,
store your damaged database with DBSTORE. Having a current backup of your damaged
database is an extra measure to protect against lost data due to a damaged log file.
3. Restore the backup of the database; this backup was created at the beginning of the
current logging maintenance cycle. Use the SHOW
database
command of DBUTIL to
find out which log file will be used to start recovery. If the TurboSTORE/iX 7x24
True-Online Backup (with ONLINE=START or ONLINE=END option) was used for
backup, the log file name is displayed. Otherwise, it will be the first log file in this
logging cycle.
4. Enter the following MPE/iX command:
:RUN DBRECOV.PUB.SYS
5. If you used the MPE/iX STORE command without ONLINE=START or ONLINE=END
option to store the database when you started your logging cycle, enter the >CONTROL
NOSTORE command of DBRECOV.
6. Enter the DBRECOV >RECOVER command below (where database name is the name of
the individual database to be recovered):
>RECOVER
database name
[,
database name2
,...,
database nameN
]
7. Enter all other desired DBRECOV commands (>FILE, >CONTROL with other options
except NOSTORE shown above, and >PRINT.) Refer to chapter 8 for more information.
8. If you want to recover the database(s), enter the DBRECOV >RUN command. Otherwise,