Brioteq

Simple Java Program to get User Inputs:

Calculate area of rectangle by getting user input values length and width. create object and call method using object.

Formula for Area of rectangle = length x width

import java.util.Scanner; //Calculate area of rectangle by getting user input values length and width //create object and call method using object //formula : Area of rectangle = length * width public class CalArea { public…

Inheriting the attributes and method from one class(super or parent class) to other class(sub class or child class) sub class- the class that inherits from another class Super class- the class being inherited from Multilevel Inheritance is inheriting like below: Super class(Grandmother) | Sub class(mother) | Sub class(child) Below is simple real time example program that calculates employee…

Scripts to find table, schema and database size:

Application team will ask ORACLE DB’s to take export backup of tables, schema and database to import in another place. To take backup, we need to know what is the size of the table or schema or database. So that we can check if we have enough space at file system level for saving export backup. Below are SQL Queries,commands and scripts to find schema size, table size and database size.

To find…

Details should be taken before stopping ORACLE DB for planned activity:

In UNIX and Linux, any planned downtime activity at OS/database level needs the oracle database to shutdown prior to the activity. If its a planned activity, taking below details helps to verify the database after activity completed. Also, it helps to validate and find the reason if any critical error occured after downtime activity. Collect the details and save it in notepad which can be removed…

Resolving Tablespace alerts- with real time example

An Oracle database consists of one or more logical storage units called Tablespaces, which collectively store all of the database’s data.Each tablespace in an Oracle database consists of one or more files called datafiles, which are physical structures that conform to the operating system in which Oracle is running.

For example, the simplest Oracle database would have one tablespace and one…

Troubleshooting ORACLE Database Out of Memory Errors-ORA 4031:

Below error will be registered in alert log of ORACLE database when out of memory error occurs: ORA 4031

An ORA-4031 error is raised when memory is unavailable for use or reuse in the System Global Area (SGA). The error message will indicate the memory pool getting errors and high level information about what kind of allocation failed and how much memory was unavailable.

The problem with…

Real time Capacity planning for ORACLE database- step by step:

Capacity planning for ORACLE database comes into play when ORACLE file system reaches above threshold level. The UNIX team will receive file system utilization alert and since its ORACLE database disk, they will ask us to clear some space to bring it under threshold.

Before asking for space, we need to check last one year database growth, tablespace utilization in database and how much space…

What is the purpose of the table_exists_action parameter in the import of data pump (impdp)?

Using a data pump import (impdp), there are four possible actions for table_exists_action:

TABLE_EXISTS_ACTION = {SKIP | APPEND | TRUNCATE | REPLACE}

As the name implies, table_exists_action is used in impdp when the table already exists in the database where the import is being executed.

table_exists_action=skip: This says to ignore the data in the import file and leave the existing…

Production and standby database- Real time Queries and Scripts:

Below are basic SQL commands and scripts to check whether database is production or standby and whether production & standby database are in sync.

1.Query to check database is production or standby:

SQL> select database_role from v$database;

DATABASE_ROLE

PRIMARY

2.Scripts to check archivelog gap in production and standby:

Execute the below query on the Primary database

SQL>…

How to find Archivelog destination?

If archivelog destination is 100% full then backup fails, which can be resolved by moving archivelog files to other location. Each and every database have unique archivelog destination.

The archive log location can be found by below commands. Either the directory name mentioned directly or stored in parameter file.

Scenario 1: IF archive location is mentioned in DB_Recovery

UNIX…

How to crosscheck Archivelog missed or moved to other location?

If archivelog file missed or deleted, the backup fails and below error will be occurred. This can be resolved by following below steps.

Below error will be occured in the backup log file:

Starting backup at 04-JUN-12 current log archived released channel: t1 RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS…

How to enable or disable Archive log mode in Oracle database 11g?

How to enable Archivelog mode in Oracle database 11g Mode of Logging

There are two types of logging modes in Oracle database :-

ARCHIVELOG :- In this type of logging whatever oracle writes in a redo log file related to transactions in database, saved to another location after a log file has been filled . This location is called Archive location. if database is in Archive log mode then in…

How to find database name and restart when UNIX server rebooted?

This is critical scenario when UNIX server rebooted and database has not been started automatically. The details of the database name will be mostly maintained by ORACLE DBA’s and in which server what databases running list also will be maintained.

Also, in the UNIX server the ORACLE_SID names will be updated in crontab. In one server, more than one databases might be running.

Example:

s…