How to Get and Install 32 bit Linux Packages

For Oracle 12c, both 32bit and 64bit packages are required to be installed, but it seems 32bit one is missing :

[root@racnode2 ~]# rpm -qa | grep glibc-devel
glibc-devel-2.17-292.0.1.el7.x86_64
[root@racnode2 ~]#

When try to install by yum, it says it has been installed already.

[root@racnode2 ~]# yum install glibc-devel
Package glibc-devel-2.17-292.0.1.el7.x86_64 already installed and latest version
Nothing to do
[root@racnode2 ~]#

Search the repository.

[root@racnode2 ~]# yum search glibc-devel
Loaded plugins: ulninfo
=================== N/S matched: glibc-devel ====================
glibc-devel.i686 : Object files for development using standard C libraries.
glibc-devel.x86_64 : Object files for development using standard C libraries.

Name and summary matches only, use "search all" for everything.

Install the 32 bit package.

[root@racnode2 ~]# yum install glibc-devel.i686
Loaded plugins: ulninfo
Resolving Dependencies
--> Running transaction check
---> Package glibc-devel.i686 0:2.17-292.0.1.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==================================================================
Package Arch Version Repository Size
==================================================================
Installing:
glibc-devel i686 2.17-292.0.1.el7 ol7_latest 1.1 M

Transaction Summary
=================================================================
Install 1 Package

Total download size: 1.1 M
Installed size: 1.0 M
Is this ok [y/d/N]: y
Downloading packages:
glibc-devel-2.17-292.0.1.el7.i686.rpm | 1.1 MB 00:00:02
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : glibc-devel-2.17-292.0.1.el7.i686 1/1
Verifying : glibc-devel-2.17-292.0.1.el7.i686 1/1

Installed:
glibc-devel.i686 0:2.17-292.0.1.el7

Complete!
[root@racnode2 ~]#