ERROR: could not load library “/opt/PostgreSQL/9.0/lib/postgresql/plperl.so”: libperl.so:

Above error thrown, when I was trying to create language plperlu. It indicates that there is a missing library libperl.so. Check out the steps performed to overcome this issue and successfully creating the plperlu language in PostgreSQL.

Method 1 (Finding the libperl.so and making softlink to that location)

postgres=# create LANGUAGE plperlu;
ERROR:  could not load library "/opt/PostgreSQL/9.0/lib/postgresql/plperl.so": libperl.so: cannot open shared object file: No such file or directory
postgres=# q

Now, search for the file libperl.so on your box and add that location to your LD_LIBRARY PATH. Dont forget switching user to postgres.

[root@localhost /]# find -name libperl.so
./usr/lib/perl5/5.10.0/i386-linux-thread-multi/CORE/libperl.so
./usr/lib/perl5/CORE/libperl.so
./usr/lib/perl5/5.10.0/i386-linux-thread-multi/CORE

[root@localhost /]# su - postgres

Set the LD_LIBRARY_PATH

-bash-4.1$ export LD_LIBRARY_PATH=/usr/lib/perl5/5.10.0/i386-linux-thread-multi/CORE:$LD_LIBRARY_PATH

Restart the cluster to effect the changes.

-bash-4.1$ pg_ctl restart
waiting for server to shut down....... done
server stopped
server starting

You are now ready to create the language.

-bash-4.1$ psql
psql (9.0.1)
Type "help" for help.

postgres=# create LANGUAGE plperlu;
CREATE LANGUAGE

Method 2 (By installing the latest ActivePerl)

Step 1:
After installing ActivePerl, set the LD_LIBRARY_PATH.

postgres@localhost:/opt/ActivePerl-5.12/lib/CORE> export LD_LIBRARY_PATH=/opt/ActivePerl-5.12/lib/CORE:/opt/PostgreSQL/9.0/lib/postgresql

Step 2:

postgres@localhost:/opt/PostgreSQL/9.0/lib/postgresql> ldd plperl.so 
       linux-vdso.so.1 =>  (0x00007fff8cf79000)
       libperl.so => /opt/ActivePerl-5.12/lib/CORE/libperl.so (0x00007fbd3d654000)
       libnsl.so.1 => /lib64/libnsl.so.1 (0x00007fbd3d40a000)
       libdl.so.2 => /lib64/libdl.so.2 (0x00007fbd3d206000)
       libm.so.6 => /lib64/libm.so.6 (0x00007fbd3cfb0000)
       libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007fbd3cd74000)
       libutil.so.1 => /lib64/libutil.so.1 (0x00007fbd3cb71000)
       libpthread.so.0 => /lib64/libpthread.so.0 (0x00007fbd3c954000)
       libc.so.6 => /lib64/libc.so.6 (0x00007fbd3c5f5000)
       /lib64/ld-linux-x86-64.so.2 (0x00007fbd3dad8000)

Step 3:

postgres@localhost:/opt/PostgreSQL/9.0/lib/postgresql> pg_ctl restart

postgres@localhost:/opt/PostgreSQL/9.0/lib/postgresql> psql
psql (9.0.2)
Type "help" for help.

postgres=# create language plperlu;
CREATE LANGUAGE

Post your comments.

–Raghav