instantclient在linux下的安装配置过程
1.新建oracle用户，使用root用户
useradd oracle
passwd oracle
2.安装oracle-instantclient
yum localinstall -y oracle-instantclient12.1-basic-12.1.0.1.0-1.x86_64.rpm oracle-instantclient12.1-sqlplus-12.1.0.1.0-1.x86_64.rpm
安装结算后，在 /usr/lib/文件夹下会出现一个新的文件夹oracle
3.修改/usr/lib/oracle文件夹的所有权
cd /usr/lib
chown -R oracle:oracle oracle
4.修改oracle用户的 .bash_profile文件，添加相应环境变量，使用oracle用户
$ vi .bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin

export PATH

export ORACLE_HOME=/usr/lib/oracle/12.1/client64
export LD_LIBRARY_PATH=/usr/lib/oracle/12.1/client64/lib
export TNS_ADMIN=$ORACLE_HOME/network/admin
export PATH=$PATH:$ORACLE_HOME/bin
5. .bash_profile文件生效
$ . ./.bash_profile
6.生成tnsnames.ora文件
$ vi /usr/lib/oracle/12.1/client64/network/admin/tnsnames.ora
CACTESTDB =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.109.10)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = cactestdb)
    )
  )
7.测试
$ sqlplus /nolog

SQL*Plus: Release 12.1.0.1.0 Production on Sat Jan 4 05:27:00 2014

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

SQL> conn scott/tiger@CACTESTDB
ERROR:
ORA-28000: the account is locked
SQL> conn system/manager@CACTESTDB
Connected.
SQL> select * from scott.emp;

     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM
---------- ---------- --------- ---------- --------- ---------- ----------
    DEPTNO
----------
      7369 SMITH      CLERK           7902 17-DEC-80        800
        20

      7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300
        30

      7521 WARD       SALESMAN        7698 22-FEB-81       1250        500
        30


     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM
---------- ---------- --------- ---------- --------- ---------- ----------
    DEPTNO
----------
      7566 JONES      MANAGER         7839 02-APR-81       2975
        20

      7654 MARTIN     SALESMAN        7698 28-SEP-81       1250       1400
        30