Om Prakash Jaiswal wrote: > I installed RHEL7.3 64 bit is enterprise version.Downloaded postgresql9.6.3 64 bit for Linux.Installed in /opt directory. > RPM -ivh postgresql9.6-plperl96.rpm.Find libperl.so. it was at /usr/lib64/perl5/CORE directory.vi /etc/ld.so.conf.d/libperl.conf < /usr/lib64/perl5/CORE ldconfig > vi /etc/ld.so.conf.d/libpostgres.conf</opt/postgres/9.6/lib > reboot machine.Now create extension plperlu.Error /opt/postgres/9.6/lib/postgresql/plperl.so undefined symbol: Perl_save_strlen. Most likely this indicates that the plperl.so is compiled against a different version of Perl than the one that provides libperl.so. I don't understand what you installed (or rather, you did not say), but I suspect you have a weird (unsupported) combination of packages. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services