Perl DBI and DBD::Oracle - Secrets of the Oracle Database - page 241

my @row=$sth->fetchrow_array;
printf "Connected as user %s.\n", $row[0];
$ chmod +x os.pl
$ ./os.pl
Connected as user OPS$ORACLE.
Connect Attributes
There are four additional attributes that may be passed to the connect method. They are
AutoCommit , ora_module_name , PrintError , and RaiseError . Each is explained in detail in the
next sections, and recommendations for optimal values in conjunction with the ORACLE
DBMS are given. You may pass one or more of these attributes to the connect method, by sepa-
rating them with commas.
AutoCommit
The setting of the AutoCommit attribute decides whether or not each execution of an INSERT ,
UPDATE , DELETE , or MERGE statement is committed immediately and implicitly or explicitly at a
later time by executing $dbh->commit . The default setting of AutoCommit is 1 (enabled). Since
committing each change individually severely degrades the response time of any application,
it is imperative that AutoCommit is explicitly set to 0 (disabled).
Module Name
The attribute ora_module_name may be used to set V$SESSION.MODULE , which is useful for letting
the database administrator identify an application. The result of setting ora_module_name is the
same as if the procedure DBMS_APPLICATION_INFO.SET_MODULE were called in an anonymous
block, but is achieved with almost no extra coding. The default value is perl on UNIX and
perl.exe on Windows. Note that module names set in this way are ignored by tracing and
client statistics functionality controlled with DBMS_MONITOR (see also related data dictionary
views DBA_ENABLED_TRACES and DBA_ENABLED_AGGREGATIONS ).
PrintError
PrintError controls the behavior of the Perl DBI in case of an error. The default value is 1 (enabled),
which means errors are printed on the standard error output. When PrintError=0 is set, the
application is responsible for printing error messages when deemed appropriate. Since not all
errors may be fatal or even indicative of a problem, the recommended setting is 0 (disabled).
RaiseError
RaiseError controls whether or not DBI raises a Perl exception whenever an error is encoun-
tered. It applies to all DBI methods except connect . As an alternative, the return codes of each
individual DBI call may be checked. Since it is much more convenient to embed many DBI
calls in an eval block that catches exceptions than coding an if else sequence for each DBI call
based on the return code, using eval is the much preferred approach. The default value of
RaiseError is 0 (disabled). When RaiseError=1 (enabled) is set, exceptions are raised whenever
a DBI call fails.