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
Chapter 4 95
Using the Database
Opening the Database
(63 per database) depending on the availability of system resources. The DBUX
remains allocated until the user's process is terminated.
• The TurboLock Table is a permanent file, TURBOLKT.PUB.SYS, that is created by
DBOPEN (if it does not exist beforehand). Thereafter, it is opened when the first user
opens any database on the system. It is purged when the system is rebooted. Each
system has only one TURBOLKT file. It is used to avoid deadlocks for all IMAGE/SQL
users. Additionally, it is also used to detect potential deadlock for TurboIMAGE/XL
users if, and only if, deadlock detection is activated by DBCONTROL mode 7.
• The Global Dynamic Multi-database Transaction Table is a permanent file,
TURBOGTX.PUB.SYS, that is created by DBXBEGIN (if it does not exist beforehand).
Thereafter, it is opened for all users who employ dynamic multi-database transaction(s)
(DMDBX). Each system has only one TURBOGTX file, and it remains on the system even
after the system is rebooted. It is used for tracking DMDBX.
• The DBQUIESCE and DBOPEN Table, QOPEN, is an unnamed global object and is first
created by DBOPEN when the first writer of any database enabled for user logging opens
a database. It is subsequently accessed only by writers of databases enabled for user
logging. Each system has only one QOPEN table, and it is purged when all processes
accessing it are terminated. It contains information pertaining to DBOPEN and user
logging process. This information is used to write to log records for DBRECOV and to
coordinate with DBQUIESCE called by TurboSTORE/iX 7x24 True-Online Backup.
• The DBQUIESCE LOCK Table, QLOCK, is an unnamed permanent global structure that
is created by DBOPEN (if it does not exist beforehand). There is one per system, and it is
accessed by all writers to all databases. It is purged only at system reboot time. It is
used for containing database information required to quiesce database(s) for
TurboSTORE/iX 7x24 True-Online Backup.
All TurboIMAGE/XL intrinsics process on the DBU except accesses for global and buffer
area information found in the two global blocks (DBG and DBB).
Passwords
When you open the database you must provide a valid password to establish your user
class number. If you do not provide one, you will be granted user class number 0. If you
are the database creator and supply a semicolon as a password, you are assigned user class
64, which grants you unlimited database access privileges. Passwords and user classes are
discussed in chapter 2.
Database Access Modes
There are eight different access modes for opening the database with the DBOPEN
procedure. Each mode determines the type of operation that you can perform on the
database, as well as the types of operations other users can perform concurrently. To
simplify the definition of the various DBOPEN modes, the following terminology is used:
• Read access modes (5, 6, 7, and 8) allow the user to locate and read data entries.
• Update access mode (2) allows read access and permits the user to replace values in
all data items except master data set key items and detail data set search and sort
items. The critical item update (CIUPDATE) option, which can permit the values of