{"id":2876,"date":"2025-03-18T18:57:21","date_gmt":"2025-03-18T18:57:21","guid":{"rendered":"https:\/\/w3buddy.com\/?p=2876"},"modified":"2026-01-15T13:10:33","modified_gmt":"2026-01-15T07:40:33","slug":"automate-oracle-dba-login-with-a-custom-alias-on-linux","status":"publish","type":"post","link":"https:\/\/w3buddy.com\/blog\/automate-oracle-dba-login-with-a-custom-alias-on-linux\/","title":{"rendered":"Automate Oracle DBA Login with a Custom Alias on Linux"},"content":{"rendered":"\n

Managing Oracle databases on an Amazon Linux 2 EC2 instance often requires switching users and setting environment variables before running SQL*Plus. This guide will walk you through setting up a custom alias (s<\/strong>) that lets you instantly connect to Oracle as sysdba without manual switching. <\/p>\n\n\n\n

Note<\/strong>– You can also use this for all other Linux OS.<\/p>\n\n\n\n

Step 1: Log in as ec2-user<\/strong><\/h2>\n\n\n\n

First, log in to your Amazon Linux 2<\/strong> EC2 instance using SSH:<\/p>\n\n\n\n

[ec2-user@ip-172-31-46-238 ~]$ uname -a\nLinux ip-172-31-46-238.ap-south-1.compute.internal 5.10.234-225.910.amzn2.x86_64 #1 SMP Fri Feb 14 16:52:40 UTC 2025 x86_64 x86_64 x86_64 GNU\/Linux\n[ec2-user@ip-172-31-46-238 ~]$\n[ec2-user@ip-172-31-46-238 ~]$ whoami\nec2-user\n[ec2-user@ip-172-31-46-238 ~]$<\/code><\/pre>\n\n\n\n
Step 2: Grant Sudo Access to ec2-user<\/strong><\/h2>\n\n\n\n
To allow ec2-user<\/strong> to switch to oracle and run SQL*Plus without a password, run:<\/p>\n\n\n\n
[ec2-user@ip-172-31-46-238 ~]$ whoami\nec2-user\n[ec2-user@ip-172-31-46-238 ~]$ sudo visudo<\/code><\/pre>\n\n\n\n
Add the following line at the end:<\/p>\n\n\n\n
ec2-user ALL=(oracle) NOPASSWD: \/bin\/bash, \/u01\/app\/oracle\/product\/19c\/db_1\/bin\/sqlplus<\/code><\/pre>\n\n\n\n
Note:<\/strong> Before adding this line, verify your SQL*Plus version and correct path by running:<\/p>\n\n\n\n
[oracle@ip-172-31-46-238 ~]$ which sqlplus\n\/u01\/app\/oracle\/product\/19c\/db_1\/bin\/sqlplus<\/code><\/pre>\n\n\n\n
If your SQL*Plus is located in a different directory, update the path accordingly in the sudoers file.<\/p>\n\n\n\n
Save and exit the editor.<\/p>\n\n\n\n
For your reference:<\/strong> <\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Step 3: Modify the .bashrc File for ec2-user<\/strong><\/h2>\n\n\n\n
To make the alias work every time you log in, edit the .bashrc file:<\/p>\n\n\n\n
Add the following alias at the end of the file:<\/p>\n\n\n\n
alias s=\"sudo -u oracle bash -c 'source \/home\/oracle\/.bash_profile; read -p \\\"Enter ORACLE_SID: \\\" ORACLE_SID; export ORACLE_SID; echo \\\"Connecting to ORACLE_SID=\\$ORACLE_SID...\\\"; sqlplus \/ as sysdba'\"<\/code><\/pre>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Explanation:<\/strong> What this above command is doing exactly…<\/h2>\n\n\n\n
    \n
  1. alias s=”…”<\/strong>\n
      \n
    • Creates an alias named s<\/strong>, so when you type s<\/strong>, it executes the enclosed command.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
    • sudo -u oracle bash -c ‘…’<\/strong>\n
        \n
      • Runs the command inside single quotes ('...'<\/code>) as the oracle<\/strong> user.<\/li>\n\n\n\n
      • -u oracle<\/strong> means switch to the <\/code>oracle <\/code><\/strong>user.<\/li>\n\n\n\n
      • bash -c ‘…’<\/strong> runs the given commands in a new bash shell.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • source \/home\/oracle\/.bash_profile;<\/strong>\n
          \n
        • Loads the Oracle environment variables defined in .bash_profile<\/strong> for the oracle<\/strong> user.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
        • read -p \\”Enter ORACLE_SID: \\” ORACLE_SID;<\/strong>\n
            \n
          • Prompts the user to enter the ORACLE_SID<\/strong> (Database System Identifier).<\/li>\n\n\n\n
          • Stores the user input in the variable ORACLE_SID<\/code>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
          • export ORACLE_SID;<\/strong>\n
              \n
            • Exports the entered ORACLE_SID<\/strong> so that SQL*Plus uses it.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • echo \\”Connecting to ORACLE_SID=\\$ORACLE_SID…\\”;<\/strong>\n
                \n
              • Displays a message indicating which ORACLE_SID<\/strong> is being used.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
              • sqlplus \/ as sysdba<\/strong>\n
                  \n
                • Launches SQL*Plus in SYSDBA<\/strong> mode, allowing administrative database operations.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
                  How It Works:<\/strong><\/h3>\n\n\n\n
                    \n
                  • Every time you type s<\/code> in the terminal:\n
                      \n
                    1. It switches to the oracle <\/strong>user.<\/li>\n\n\n\n
                    2. Loads Oracle environment variables.<\/li>\n\n\n\n
                    3. Asks for the ORACLE_SID<\/strong>.<\/li>\n\n\n\n
                    4. Exports it for the session.<\/li>\n\n\n\n
                    5. Displays which SID it’s connecting to.<\/li>\n\n\n\n
                    6. Opens SQL*Plus<\/strong> as sysdba<\/strong>.<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n\n\n\n
                      This ensures that even if multiple databases are running, you manually select the correct one each time! \u2705<\/p>\n\n\n\n
                      Step 4: Apply the Changes<\/strong><\/h2>\n\n\n\n
                      After saving the file, apply the changes:<\/p>\n\n\n\n
                      source ~\/.bashrc<\/code><\/pre>\n\n\n\n
                      Step 5: Test the New Alias<\/strong> from ec2-user<\/h2>\n\n\n\n
                      Now, simply run: s<\/strong> and see the magic…<\/p>\n\n\n\n
                        \n
                      1. When database already up and running.<\/li>\n<\/ol>\n\n\n\n
                        \"\"<\/figure>\n\n\n\n
                          \n
                        1. When database is down then also it will ask for Oracle SID.<\/li>\n<\/ol>\n\n\n\n
                          \"\"<\/figure>\n\n\n\n
                          Conclusion<\/strong><\/h2>\n\n\n\n
                          Now, with just a single command (s<\/code>), you can quickly access SQL*Plus as sysdba <\/strong>without manually switching users or setting environment variables. This saves time and ensures consistency in database administration on Amazon Linux 2.<\/p>\n\n\n\n
                          Let me know if you need any further refinements!<\/p>\n","protected":false},"excerpt":{"rendered":"
                          Managing Oracle databases on an Amazon Linux 2 EC2 instance often requires switching users and setting environment variables before running SQL*Plus. This guide will walk you through setting up a custom alias (s) that lets you instantly connect to Oracle as sysdba without manual switching. Note– You can also use this for all other Linux […]<\/p>\n","protected":false},"author":1,"featured_media":2882,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"googlesitekit_rrm_CAowu461DA:productID":"","footnotes":""},"categories":[1225],"tags":[],"class_list":["post-2876","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/posts\/2876","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/comments?post=2876"}],"version-history":[{"count":3,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/posts\/2876\/revisions"}],"predecessor-version":[{"id":2887,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/posts\/2876\/revisions\/2887"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/media\/2882"}],"wp:attachment":[{"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/media?parent=2876"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/categories?post=2876"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/w3buddy.com\/blog\/wp-json\/wp\/v2\/tags?post=2876"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}