OraExplain, an Oracle tuning tool that DBAs can use to explain SQL execution plans and examine their SQL cache, was the first widely available tool that combined Perl/Tk and Perl DBI. OraExplain was created by Alan Burlison, a Solaris kernel gatekeeper for Sun Microsystems, and Tim Bunce quickly added the original ora_explain.pl module to the DBD::Oracle driver download bundle. So when you obtain DBD::Oracle , you'll get OraExplain automatically (at least if you're installing on Unix).
Figure 3-5. Finding and running OraExplain
Follow these installation steps: