Postgresql – Unable to create oracle_fdw extension on Postgres

I am following the instructions here to install Oracle foreign data wrapper, oracle_fdw, on a PostgreSQL server.

Oracle version: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 – 64bit Production, running on Red Hat Linux 7.2

PostgreSQL version: PostgreSQL 9.4.4 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.7.2-5) 4.7.2, 64-bit, running on Debian 7 (wheezy).

I was able to install sqlplus and connect from PostgreSQL server to Oracle server using sqlplus successfully, so connectivity is not a problem.

But when I try to create the extension, I get the following error:

postgres=# create extension oracle_fdw;
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

Then I took clues from https://github.com/dalibo/pg_qualstats/issues/1 and added oracle_fdw to shared_preload_libraries in postgresql.conf like this:

shared_preload_libraries = 'oracle_fdw'

but now I can't restart Postgres:

# service postgresql restart
[....] Restarting PostgreSQL 9.4 database server: main[....] The PostgreSQL server failed to start. Please check the log output: t=2016-09-15 11:05:42 PDT d= h= p=23300 a=FATAL: XX000: invalid cache ID[FAILt=2016-09-15 11:05:42 PDT d= h= p=23300 a=LOCATION: SearchSysCacheList, syscache.c:1219 ... failed!
 failed!

Looking into /var/log/postgresql/postgresql-9.4-main.log I only see these two lines:

t=2016-09-15 11:05:42 PDT d= h= p=23300 a=FATAL:  XX000: invalid cache ID: 41
t=2016-09-15 11:05:42 PDT d= h= p=23300 a=LOCATION:  SearchSysCacheList, syscache.c:1219

Removing oracle_fdw from shared_preload_libraries allows postgres to be restarted, so this is the one causing restart to fail. So I removed oracle_fdw from shared_preload_libraries and kept it just like this in postgresql.conf:

shared_preload_libraries = ''

Then I was able to restart Postgres.

Here are the exact steps done:

OS version for PostgreSQL server

# cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 7 (wheezy)"
NAME="Debian GNU/Linux"
VERSION_ID="7"
VERSION="7 (wheezy)"
ID=debian
ANSI_COLOR="1;31"
HOME_URL="http://www.debian.org/"
SUPPORT_URL="http://www.debian.org/support/"
BUG_REPORT_URL="http://bugs.debian.org/"
root@app-4:/# cat /etc/debian_version
7.8
root@app-4:/# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 7.8 (wheezy)
Release:    7.8
Codename:   wheezy

Installation of Oracle Instant Client

Installed using the instructions given here:
https://help.ubuntu.com/community/Oracle%20Instant%20Client

I downloaded the following rpm files from http://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html:

• oracle-instantclient-basic-10.2.0.3-1.x86_64.rpm
• oracle-instantclient-devel-10.2.0.3-1.x86_64.rpm
• oracle-instantclient-sqlplus-10.2.0.3-1.x86_64.rpm

and installed them on the PostgreSQL server using the following commands:

# apt-get install alien
# alien -i oracle-instantclient-basic-10.2.0.3-1.x86_64.rpm
# alien -i oracle-instantclient-devel-10.2.0.3-1.x86_64.rpm
# alien -i oracle-instantclient-sqlplus-10.2.0.3-1.x86_64.rpm

Confirming the installations:

# dpkg --list | grep -i oracle
ii  oracle-instantclient-basic         10.2.0.3-2                    amd64        Instant Client for Oracle Database 11g
ii  oracle-instantclient-devel         10.2.0.3-2                    amd64        Development headers for Instant Client.
ii  oracle-instantclient-sqlplus       10.2.0.3-2                    amd64        SQL*Plus for Instant Client.

Connecting to Oracle server using sqlplus

# su - postgres
postgres@app-4:~$ sqlplus <ORACLE_USER>/<ORACLE_PASS>@//<ORACLE_HOST>:<ORACLE_PORT>/<SID>

SQL*Plus: Release 10.2.0.3.0 - Production on Fri Sep 16 09:55:02 2016

Copyright (c) 1982, 2006, Oracle.  All Rights Reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> select count(*) from <TEST_TABLE>;

  COUNT(*)
----------
    937530

SQL> 

So this works fine.

Installing oracle_fdw

Downloaded oracle_fdw version 1.4.0 i.e. file oracle_fdw-1.4.0.zip from
http://pgxn.org/dist/oracle_fdw/

Then unzipped it and installed it like this:

root@app-4:/home/arun/oracle_fdw-1.4.0# ls
CHANGELOG  LICENSE   META.json             oracle_fdw--1.1.sql  oracle_fdw.control  oracle_fdw.o   oracle_gis.c  oracle_utils.c  README.oracle_fdw  TODO
expected   Makefile  oracle_fdw--1.0--1.1.sql  oracle_fdw.c     oracle_fdw.h    oracle_fdw.so  oracle_gis.o  oracle_utils.o  sql
root@app-4:/home/arun/oracle_fdw-1.4.0# make
...
root@app-4:/home/arun/oracle_fdw-1.4.0# make install
/bin/mkdir -p '/usr/lib/postgresql/9.4/lib'
/bin/mkdir -p '/usr/share/postgresql/9.4/extension'
/bin/mkdir -p '/usr/share/postgresql/9.4/extension'
/bin/mkdir -p '/usr/share/doc/postgresql-doc-9.4/extension'
/usr/bin/install -c -m 755  oracle_fdw.so '/usr/lib/postgresql/9.4/lib/oracle_fdw.so'
/usr/bin/install -c -m 644 oracle_fdw.control '/usr/share/postgresql/9.4/extension/'
/usr/bin/install -c -m 644 oracle_fdw--1.1.sql oracle_fdw--1.0--1.1.sql '/usr/share/postgresql/9.4/extension/'
/usr/bin/install -c -m 644 README.oracle_fdw '/usr/share/doc/postgresql-doc-9.4/extension/'

Creating extension in Postgres

root@app-4:/# su - postgres
postgres@app-4:~$ psql
psql (9.4.4)
Type "help" for help.

postgres=# create extension oracle_fdw;
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!> \q

Stack Trace

I installed the GNU debugger (gdb) as recommended by Laurenz Albe in his answer and got the following stack trace (without the debugging symbols for now):

Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
#0  0x0000000000000000 in ?? ()
#1  0x00007ff657dfcc99 in DirectFunctionCall1Coll ()
#2  0x00007ff657de19a9 in ?? ()
#3  0x00007ff657de3037 in SearchCatCacheList ()
#4  0x00007ff4c5fcce7d in _PG_init () at oracle_fdw.c:648
#5  0x00007ff657dfb717 in ?? ()
#6  0x00007ff657dfc051 in load_external_function ()
#7  0x00007ff657b6b486 in fmgr_c_validator ()
#8  0x00007ff657dfdeba in OidFunctionCall1Coll ()
#9  0x00007ff657b6aedc in ProcedureCreate ()
#10 0x00007ff657bcf645 in CreateFunction ()
#11 0x00007ff657d14e73 in ?? ()
#12 0x00007ff657d140c7 in standard_ProcessUtility ()
#13 0x00007ff657bc89ed in ?? ()
#14 0x00007ff657bc98de in CreateExtension ()
#15 0x00007ff657d154c1 in ?? ()
#16 0x00007ff657d140c7 in standard_ProcessUtility ()
#17 0x00007ff657d11243 in ?? ()
#18 0x00007ff657d11e96 in ?? ()
#19 0x00007ff657d12b3d in PortalRun ()
#20 0x00007ff657d0fb1a in PostgresMain ()
#21 0x00007ff657acbdad in ?? ()
#22 0x00007ff657caf351 in PostmasterMain ()
#23 0x00007ff657acccba in main ()
Continuing.

Program terminated with signal SIGSEGV, Segmentation fault.
The program no longer exists.

UPDATE: I was able to install the extension on Postgres 9.4.9 running on debian 8 (8.6, jessie). I used Oracle instant client version 12.1.0.2.0-1 and oracle_fdw version 1.5.