TRANSACTION BEGIN

Begin Tracking Record Changes

This directive must be executed before I/O directives that alter or delete the contents of a record can be recovered. Users may perform many I/O operations before all or none of them are made permanently to the data base. All records that have been altered are locked until a commitment has been made in regard to this TRANSACTION BEGIN.

Syntax

TRANSACTION BEGIN [,ERR=line-ref|,ERC=error-code]

line-ref

is the program line number or label to branch to if this directive produces an error.

error-code

is a programmer-defined error code. Valid values are positive or negative whole numbers.

Remarks

If a LOG OPEN directive is not executed before a TRANSACTION BEGIN directive, the TRANSACTION BEGIN will perform a LOG OPEN using the values in PRM TPLOGPATH and TPLOGNAME. The default value for TPLOGPATH is /usr/lib/basic/TPLOGS (or your Windows home path) and the default value for TPLOGNAME is “TPLOG.”+ TaskId.

Only one TRANSACTION BEGIN directive can be active.

You cannot perform a LOG CLOSE in between a TRANSACTION BEGIN and a COMMIT or ROLLBACK sequence.

Starting with release level 8.3.1 you can OPEN additional data files after the
TRANSACTION BEGIN command is executed.

Starting with release level 8.6.0 you can CLOSE channels between a TRANSACTION BEGIN and a COMMIT or ROLLBACK. However, CLOSEd channels will not be available until a COMMIT or ROLLBACK directive is executed. This restriction ensures that all locks will remain in effect.

Examples

00010  TRANSACTION BEGIN
00020  CH1=UNT; OPEN(CH1) "MSORTFILE"
00030  CH2=UNT; OPEN(CH2) "DIRECTFILE"
00040  CLEAR ERC;
       K$ = KEY(CH1);
       READ RECORD(CH1) A$;
       WRITE RECORD (CH2,KEY=K$,ERC=99) A$;
       REMOVE(CH1,KEY=K$,ERC=99);
       IF ERC
        ROLLBACK
       ELSE
         COMMIT
       FI

See also

COMMIT, LOG CLOSE, LOG OPEN, and ROLLBACK directives

From the Thoroughbred Basic Language Reference, Volume III: R–Z, version 8.9.1. Open this page in the PDF