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<head><title>Using Fastexport with DBD::Teradata</title></head>
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<center><h2>Using Fastexport with DBD::Teradata</h2></center>
<p>
DBD::Teradata 2.2.0 provides improved support for Fastexport.
Using Fastexport with DBD::Teradata requires some special considerations.
<p>
<b>DBD::Teradata does not support recovery logging of utilities; i.e.,
you cannot PAUSE and then restart DBD::Teradata-based utility applications.</b>
<p>
The attributes hash provided to tdat_UtilitySetup includes the following
keys:<p>
<table border=1>
<tr bgcolor=orange><th>Attribute</th><th>Required ?</th><th width="70%">Description</th></tr>
<tr>
<td align=center valign=top><b>Utility</b></td>
<td align=center valign=top>Yes</td>
<td valign=top>set to 'EXPORT'</td></tr>
<tr>
<td align=center valign=top><b>SQL</b></td>
<td align=center valign=top>Yes</td>
<td valign=top>
A SELECT statement to be used for the export. Note that parameterized SELECTs, and multi-statement
SELECTs have not yet been tested.</td></tr>
<tr>
<td align=center valign=top><b>Target</b></td>
<td align=center valign=top>Yes</td>
<td valign=top>can be set to either a subroutine reference, a file description.<p>
A file description is specified as<p>
<code>< VARTEXT 'c' | INDICDATA | DATA > <i>filename</i></code><p>
where 'c' is the separator character. Use '|' for compatibility with
the default Teradata VARTEXT file format. INDICDATA indicates a fastload
formatted file with indicator bytes, and DATA indicates a fastload
formatted file without indicator bytes.</td></tr>
<tr>
<td align=center valign=top><b>Report</b></td>
<td align=center valign=top>No</td>
<td valign=top>a subroutine reference which is called with a status message as the Fastexport progresses.</td></tr>
<tr>
<td align=center valign=top><b>Sessions</b></td>
<td align=center valign=top>Yes</td>
<td valign=top>the number of export sessions to use</td></tr>
<tr>
<td align=center valign=top><b>Context</b></td>
<td align=center valign=top>No</td>
<td valign=top>a hashref that can contain anything the application
desires; it will be passed to the Source subroutine reference each time
records are to be collected</td></tr>
<tr>
<td align=center valign=top><b>MP</b></td>
<td align=center valign=top>No</td>
<td valign=top>when set to a nonzero numeric value, or the string 'nothreads',
causes multiple processes to be fork()'d, 1 per export session.
When set to the string 'threads', causes multiple threads to be spawned, 1 per export session.
This attribute may provide performance improvement
on certain platforms (esp. multiprocessor platforms).</td></tr>
<tr>
<td align=center valign=top><b>Retry</b></td>
<td align=center valign=top>No</td>
<td valign=top>either a scalar or arrayref; if scalar, indicates the number of seconds
to wait between retrying to start the fastexport in the event the prior attempt failed due to
no remaining utility job slots available on the database. If an arrayref, the first
element is the number of seconds between retries, and the second element is the maximum
number of retry attempts. The scalar form will retry indefinitely.</td></tr>
</table><p>
<h3>Examples</h3>
<h4>Multijob MP Export with subroutine source</h4>
<pre><code>
my $ctldbh = DBI->connect('dbi:Teradata:dbc', $username, $password,
{ RaiseError => 0, PrintError => 0, tdat_lsn => 0 });
my $total = $ctldbh->tdat_UtilitySetup(
{
Utility => 'EXPORT',
Sessions => $sesscount,
SQL => 'SELECT * FROM alltypetst',
Report => \&report_cb,
Target => \&save_data,
Context => {
Count => \$count,
Runtime => \$mlstarted,
Base => [ 0, 1000000 ]
},
MP => 1,
Retry => [ 120, 3] # retry every 2 minutes up to 3 times
});
print $ctldbh->errstr
unless ($total && ($total > 0));
sub report_cb {
my ($msg) = @_;
print $msg, "\n";
}
</code>
</pre>
<h4>Multithreaded MP Export with INDICDATA source</h4>
<pre>
<code>
my $ctldbh = DBI->connect('dbi:Teradata:dbc', $username, $password,
{ RaiseError => 0, PrintError => 0, tdat_lsn => 0 });
my $total = $ctldbh->tdat_UtilitySetup(
{
Utility => 'EXPORT',
Sessions => $sesscount,
SQL => 'SELECT * FROM alltypetst',
Report => \&report_cb,
Source => 'INDICDATA rawdata.dat',
MP => 'threads'
});
print $ctldbh->errstr
unless ($total && ($total > 0));
</code>
</pre>
<h4>Multijob MP Export with VARTEXT source</h4>
<pre>
<code>
my $ctldbh = DBI->connect('dbi:Teradata:dbc', $username, $password,
{ RaiseError => 0, PrintError => 0, tdat_lsn => 0 });
my $total = $ctldbh->tdat_UtilitySetup(
{
Utility => 'EXPORT',
Sessions => $sesscount,
SQL => 'SELECT * FROM alltypetst',
Report => \&report_cb,
Source => "VARTEXT '|' vardata.txt",
MP => 1
});
print $ctldbh->errstr
unless ($total && ($total > 0));
</code>
</pre>
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