DATABASE LINK FROM ORACLE TO MySQL

All bold statements are shell commands or configuration steps.

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DATABASE LINK FROM ORACLE TO MySQL

1. Introduction

This document describes steps to create a database link between Oracle to MySQL (Heterogeneous Services) / Oracle Gateway, Regarding Oracle Documentation Gateways will integrate with any number of non-Oracle systems from an Oracle application.

All bold statements are shell commands or configuration steps.

2. Database Link Configuration

A database link is a schema object in one database that enables you to access objects on another database. The other database need not be an Oracle Database system. However, to access non-Oracle systems you must use Oracle Heterogeneous Services.

It is a connection between two physical database servers that allows a client to access them as one logical database.

2.1 Configure Database Link from ORACLE to MySQL

To start Configure Database Link we need to follow the below steps:

Step #1:-

Determine the Version for dg4odbc on the Operating system using

>file $ORACLE_HOME/bin/dg4odbc

This Command Explain which version of ODBC Driver.

Step #2:-

Install unixODBC and MySQL connector (This step should be done as root user).

# yum install unixODBC

# yum install mysql-connector-odbc

Step #4:-

(As Oracle User). Export Variables.

In Linux – .bash_profile

In Solaris -.profile

export LD_LIBRARY_PATH=/usr/lib64:/usr/lib64/libmyodbc5.so:$ORACLE_HOME/lib

export ODBCINI=/etc/odbc.ini

export ODBCSYSINI=/etc

Step #5:-

(As Root User).

Configure odbc.ini located in (/etc), the file should look like the below:-

# Driver from the mysql-connector-odbc package

# Setup from the unixODBC package

[MySQL]

Description = ODBC for MySQL

Driver = /usr/lib64/libmyodbc5.so

Setup = /usr/lib64/libodbcmyS.so

# Driver64 = /usr/lib64/libmyodbc5.so

# Setup64 = /usr/lib64/libodbcmyS.so

FileUsage = 1

DATABASE = cs_dm_stage

UID = <username>

PWD = welcome123!@#

Option = 3

SERVER = nyads2hslrdb02.na.weightwatchers.net

PORT = 3306

It’s configured.

Step #6:-

As Oracle User:-

[root@server etc]# cd /usr/lib64

[root@server lib64]# ldd libmyodbc5.so

linux-vdso.so.1 => (0x00007fff1afff000)

libltdl.so.7 => /usr/lib64/libltdl.so.7 (0x00007f4b16c01000)

libmysqlclient_r.so.16 => /usr/lib64/mysql/libmysqlclient_r.so.16 (0x00007f4b1686c000)

libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f4b16635000)

libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f4b1641c000)

libm.so.6 => /lib64/libm.so.6 (0x00007f4b16197000)

libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f4b15f7a000)

libssl.so.10 => /usr/lib64/libssl.so.10 (0x00007f4b15d0d000)

libcrypto.so.10 => /usr/lib64/libcrypto.so.10 (0x00007f4b15928000)

libz.so.1 => /lib64/libz.so.1 (0x00007f4b15712000)

libodbcinst.so.2 => /usr/lib64/libodbcinst.so.2 (0x00007f4b15501000)

libc.so.6 => /lib64/libc.so.6 (0x00007f4b1516c000)

libdl.so.2 => /lib64/libdl.so.2 (0x00007f4b14f68000)

libfreebl3.so => /usr/lib64/libfreebl3.so (0x00007f4b14d65000)

/lib64/ld-linux-x86-64.so.2 (0x0000003f64c00000)

libgssapi_krb5.so.2 => /lib64/libgssapi_krb5.so.2 (0x00007f4b14b20000)

libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f4b14839000)

libcom_err.so.2 => /lib64/libcom_err.so.2 (0x00007f4b14635000)

libk5crypto.so.3 => /lib64/libk5crypto.so.3 (0x00007f4b14408000)

libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f4b141fd000)

libkeyutils.so.1 => /lib64/libkeyutils.so.1 (0x00007f4b13ff9000)

libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f4b13ddf000)

libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f4b13bc0000)

The Most Important Thing in the above output is to check if there is nothing in the library “Not Found”.

Step #7:-

(As Oracle User).

Test connection using odbc only, Only on OS Level

# ./isql –v MySQL

The below is output:-

Connected

Until this step we didn’t do anything only configure odbc, next step will explain how to configure Oracle.

Step #8:-

Configuration for Oracle Start with initSID.ora file. Oracle already create a template located in $ORACLE_HOME/hs/admin just copy it with the new name, the default one is initdg4odbc.ora we can leave without change and edit it.

**SQL > Select * from “cs_memberdata_staging”@ mysql_dblink;**