I am using sql*plus bind variables because I needed to connect to 2 different databases
and compare their results.
The standby database is in mounted mode, so this precludes the idea of trying to get this information
across a database link.

The sql script is then called by a shell script. (check_stby.sh) which gets called by
a host-user-defined-metric in Enterprise Manager’s Grid Control system.

If the returned value exceeds the metric’s threshold, an alert is triggered and I receive an
email warning me to check the status of the standby database.

check_stby.sql

set echo off
set feedback off
set termout off
VARIABLE prim_seq NUMBER
variable stby_seq number
variable diff number

connect sys/xxxx@primarydb.world.com as sysdba
begin
select max(sequence#)into :prim_seq from v$archived_log;
end;
/

connect sys/xxxx@standbydb.world.com as sysdba
begin
select max(sequence#) into :stby_seq from v$log_history;
end;
/

begin
:diff := :prim_seq - :stby_seq   ;
end;
/
exit :diff;

check_stby.sh

#!/bin/ksh

export ORACLE_HOME=/home/oracle/product/10.2.0

$ORACLE_HOME/bin/sqlplus -s /nolog @check_stby.sql

echo "em_result="$?"
"

Recommended reading:

Save it to a file on your server or PC and run it to complete dropping the Oracle demo tables.

Demo_drop.sql

====== start of section to cut ======

--
-- Copyright (c) Oracle Corporation 1988, 2000.  All Rights Reserved.
--
--
-- DESCRIPTION
--   This script drops the SQL*Plus demonstration tables created by
--   demobld.sql.  It should be STARTed by each owner of the tables.
--
-- USAGE
--   From within SQL*Plus, enter:
--       START demodrop.sql

SET TERMOUT ON
PROMPT Dropping demonstration tables.  Please wait.
SET TERMOUT OFF

DROP TABLE EMP;
DROP TABLE DEPT;
DROP TABLE BONUS;
DROP TABLE SALGRADE;
DROP TABLE DUMMY;

SET TERMOUT ON
PROMPT Demonstration table drop is complete.

EXIT

====== end of section to cut ======

Drop scott user

If you want to drop the scott user, do the following (login as DBA ):

Save it to a file on your server or PC and follow the instructions in the
oracle sqlplus demo table article
to complete building the Oracle demo tables.

Demobld.sql

====== start of section to cut ======

--
-- Copyright (c) Oracle Corporation 1988, 2000.  All Rights Reserved.
--
-- NAME
--   demobld.sql
--
-- DESCRIPTION
--   This script creates the SQL*Plus demonstration tables in the
--   current schema.  It should be STARTed by each user wishing to
--   access the tables.  To remove the tables use the demodrop.sql
--   script.
--
--  USAGE
--    From within SQL*Plus, enter:
--        START demobld.sql

SET TERMOUT ON
PROMPT Building demonstration tables.  Please wait.
SET TERMOUT OFF

DROP TABLE EMP;
DROP TABLE DEPT;
DROP TABLE BONUS;
DROP TABLE SALGRADE;
DROP TABLE DUMMY;

CREATE TABLE EMP
       (EMPNO NUMBER(4) NOT NULL,
        ENAME VARCHAR2(10),
        JOB VARCHAR2(9),
        MGR NUMBER(4),
        HIREDATE DATE,
        SAL NUMBER(7, 2),
        COMM NUMBER(7, 2),
        DEPTNO NUMBER(2));

INSERT INTO EMP VALUES
        (7369, 'SMITH',  'CLERK',     7902,
        TO_DATE('17-DEC-1980', 'DD-MON-YYYY'),  800, NULL, 20);
INSERT INTO EMP VALUES
        (7499, 'ALLEN',  'SALESMAN',  7698,
        TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600,  300, 30);
INSERT INTO EMP VALUES
        (7521, 'WARD',   'SALESMAN',  7698,
        TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250,  500, 30);
INSERT INTO EMP VALUES
        (7566, 'JONES',  'MANAGER',   7839,
        TO_DATE('2-APR-1981', 'DD-MON-YYYY'),  2975, NULL, 20);
INSERT INTO EMP VALUES
        (7654, 'MARTIN', 'SALESMAN',  7698,
        TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);
INSERT INTO EMP VALUES
        (7698, 'BLAKE',  'MANAGER',   7839,
        TO_DATE('1-MAY-1981', 'DD-MON-YYYY'),  2850, NULL, 30);
INSERT INTO EMP VALUES
        (7782, 'CLARK',  'MANAGER',   7839,
        TO_DATE('9-JUN-1981', 'DD-MON-YYYY'),  2450, NULL, 10);
INSERT INTO EMP VALUES
        (7788, 'SCOTT',  'ANALYST',   7566,
        TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);
INSERT INTO EMP VALUES
        (7839, 'KING',   'PRESIDENT', NULL,
        TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);
INSERT INTO EMP VALUES
        (7844, 'TURNER', 'SALESMAN',  7698,
        TO_DATE('8-SEP-1981', 'DD-MON-YYYY'),  1500,    0, 30);
INSERT INTO EMP VALUES
        (7876, 'ADAMS',  'CLERK',     7788,
        TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);
INSERT INTO EMP VALUES
        (7900, 'JAMES',  'CLERK',     7698,
        TO_DATE('3-DEC-1981', 'DD-MON-YYYY'),   950, NULL, 30);
INSERT INTO EMP VALUES
        (7902, 'FORD',   'ANALYST',   7566,
        TO_DATE('3-DEC-1981', 'DD-MON-YYYY'),  3000, NULL, 20);
INSERT INTO EMP VALUES
        (7934, 'MILLER', 'CLERK',     7782,
        TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);

CREATE TABLE DEPT
       (DEPTNO NUMBER(2),
        DNAME VARCHAR2(14),
        LOC VARCHAR2(13) );

INSERT INTO DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');
INSERT INTO DEPT VALUES (20, 'RESEARCH',   'DALLAS');
INSERT INTO DEPT VALUES (30, 'SALES',      'CHICAGO');
INSERT INTO DEPT VALUES (40, 'OPERATIONS', 'BOSTON');

CREATE TABLE BONUS
        (ENAME VARCHAR2(10),
         JOB   VARCHAR2(9),
         SAL   NUMBER,
         COMM  NUMBER);

CREATE TABLE SALGRADE
        (GRADE NUMBER,
         LOSAL NUMBER,
         HISAL NUMBER);

INSERT INTO SALGRADE VALUES (1,  700, 1200);
INSERT INTO SALGRADE VALUES (2, 1201, 1400);
INSERT INTO SALGRADE VALUES (3, 1401, 2000);
INSERT INTO SALGRADE VALUES (4, 2001, 3000);
INSERT INTO SALGRADE VALUES (5, 3001, 9999);

CREATE TABLE DUMMY
        (DUMMY NUMBER);

INSERT INTO DUMMY VALUES (0);

COMMIT;

SET TERMOUT ON
PROMPT Demonstration table build is complete.

EXIT

====== end of section to cut ======

Recommended reading:

Scott is the standard example schema used to run queries and scripts to show how Oracle works.

Scott schema creation.

Create the scott user on your database if it does not already exist.

Connect to the database as a dba user, like sys or system.

Demobuild execution.

The script to create the tables (demobld.sql) is located in
%oracle_home%sqlplusdemodemobld.sql
or
$ORACLE_HOME/sqlplus/demo/demobld.sql,
for either windows or unix.

Depending on which version of Oracle you use, it will create the following tables:

• EMP
• DEPT
• BONUS
• SALGRADE
• DUMMY

How to run it:

To drop the demo tables, run the demodrop.sql script in the same directory.