TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

138 Chapter5
TurboIMAGE/XL Library Procedures
Using TurboIMAGE/XL Intrinsics
Database Protection
When each procedure is called, TurboIMAGE/XL verifies that the requested operation is
compatible with the user class number and access mode established when the database is
opened.
Unused Parameters
When calling some procedures for a specific purpose, one of the parameters can be ignored;
however, it still must be listed in the call statement. An application program may find it
useful to set up a variable named Not_Used_Parm or DUMMY to be listed as the unused
parameter as a reminder that the value of the parameter does not affect the procedure call.
Refer to the examples in chapter 6.
The Status Array
The status array is a communication area. If the procedure executes successfully, the
contents of the array reflect this as described under each intrinsic discussion in this
chapter. If the procedure fails, standard error information is returned in the array as
described in this chapter and appendix A.
Transactions
TurboIMAGE/XL transactions are defined below:
Refer to chapters 4 and 7 for more information on transactions.
Table 5-3. Types of Transactions
Transaction Definition
Single A single call to an intrinsic. A single transaction is not delimited by DBBEGIN and
DBEND, or DBXBEGIN and DBXEND.
Logical A sequence of one or more procedure calls that begins with a DBBEGIN or
DBXBEGIN call and ends with a DBEND or DBXEND call. A logical transaction can
contain several intrinsic calls, but is logically considered one transaction.
Static A logical transaction that begins with a DBBEGIN call and ends with a DBEND call.
A static transaction spans only one database, and can be recovered with
DBRECOV.
Dynamic A logical transaction that begins with a DBXBEGIN call and ends with a DBXEND
call. A dynamic transaction can be rolled back dynamically with DBXUNDO. A
dynamic transaction spans only one database.
Multiple
database
A logical transaction that spans more than one database. A multiple database
transaction begins with a DBBEGIN call and ends with a DBEND call. A multiple
database transaction can be recovered with DBRECOV. A dynamic transaction can
also span more than one database by beginning with a DBXBEGIN call and ending
with a DBEND call.