Wednesday, January 6, 2021

What is Character Functions

 


Hello, friends in this article we are going to discuss how to use Character Functions in SQL. The character functions accept only Character type values and return in character and number both.


Type of Character Functions

There are eight types of Character Functions in SQL.

  1. CONCAT
  2. SUBSTR
  3. LENGTH
  4. INSTR
  5. LPAD
  6. RPAD
  7. REPLACE
  8. TRIM

So, let's understand the working of each function one by one.

1. CONCAT

The CONCAT function joint two or more strings and display as a single string. We can use a minimum of two strings with the CONCAT function. For example, we have two strings like “OCP” and “TECHNOLOGY” and we want to display both strings together.

SQL> SELECT  CONCAT('OCP','TECHNOLOGY') FROM DUAL;

The output from the above query is “OCPTECHNOLOGY“.

2. SUBSTR

The SUBSTR function Retrieve a part of the string as specified the length in function, as you can see in the below output. As we have a string like “OCPTECHNOLOGY” and we just want to display only the first three characters of the string.

SQL> SELECT SUBSTR('OCPTECHNOLOGY',1,3) FROM DUAL;

So, from the above query, we get the “OCP” as output.

3. LENGTH

The LENGTH function calculates the length of a string as a numeric value. Suppose we have a string like “OCPTECHNOLOGY” and we just want to count the letters of the sting, so you can use the length function.

SQL> SELECT LENGTH('OCPTECHNOLOGY') FROM DUAL;

The output is 13.

4. INSTR

The INSTR function shows the position of a given character in number. For example, you want to find out the position of “T” later from the “OCPTECHNOLOGY” string.

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Wednesday, January 15, 2020

Data Guard Physical Standby and Logical Standby Database Architecture in...

In this tutorial, we will learn
-Types of Standby Databases
-Background Services
-Data Guard Architecture
-Protection mode of Data Guard

Types of Standby Database
-Physical Standby
-Logical Standby

Discuss Later
Snapshot Standby
Active-Standby

Background Process work behind the Data Guard Configuration
*LNS - Log Network Service ( Running on the Primary Database)
*RFS - Remote File Service (Running on the Standby Database)
*MRP - Media Recovery Process (Running on the Standby Database)
*LSP - Logical Standby Process (Running on Logical Standby Database)

Standby
*Standby is a block to block a copy of the production database.
*The Standby Database also called is Physical Standby.
*The MRP process Manage the recovery which applies the received redo on physical standby.

Logical Standby
*Convert received redo in SQL statement and execute on standby.
*Logical standby database read/write operations (not on the replicated tables)
*Structure not same .
*Involve a few extra processes.
*Not all data types are supported.

Redo Transport Services
*SYNC - Synchronous Redo Transport
*ASYNC - Asynchronous Redo Transport

Note:- Both have the same responsibility to transport redo from production to standby.

SYNC - Synchronous Redo Transport
*Zero Data Loss
*Performance impact

ASYNC - Asynchronous Redo Transport
*Data Loss
*Zero performance impact

Protection mode for Data Guard
Maximum Performance
*It uses ASYNC redo transport
*Priority given to performance
*Minimum data loss


Maximum Availability
*It uses SYNC redo transport (Required)
*First Priority given availability and second priority is data protection
*If standby not available, the primary will wait and then proceed

Maximum Protection
*It uses SYNC redo transport (Required)
*Zero data loss
*If standby not available, the primary will be hangs and database will be abort
*Suggested more than one standby configured

#DataGuard #Architecture #DGtutorial







Sunday, January 5, 2020

Oracle Data Guard Tutorial Full Series in Hindi

Oracle Data Guard full course series in Hindi.



Hello Friends, in this series we are going to cover full data Guard tutorial

in the first part, we cover the following topics.





Our Topics

1. Introduction to Oracle Data Guard

2. How to configure oracle data guard from scratches.

3. How to configure the DG Broker.

4. How to manage Physical and Logical standby.

5. How to switchover the role.

6. How to convert the physical standby database into Active standby

7. How to convert the physical standby database into snapshot standby



Please write your views in the comment box.



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How to create Database in RPM base Installation Oracle 19c - Full Guide

In this video, we are going to demonstrate to you how to create a database in RPM-based installation database 19c, Full guide on the Production environment.



For more detail please visit on my website Click Here





Wednesday, August 7, 2019

How to create and use DB Link between two servers step by step

In this video, I'm going to show you how to create DB Link between two oracle databases, and how to use DB link remotely,
DB Link complete tutorial step by step.

oracle find objects using database link.
oracle heterogeneous services 12c.
database link from oracle to sql server linux.
heterogeneous db link in oracle.
how to create dblink between two different databases in oracle.
create database link using tns.
grant create database link.
how to check db links in oracle.


How to Create a Dblink, dblink in 12c and 11g, creation of database link, heterogeneous dblink,


#DBLink #dblinkin12c #oracledblink







Thursday, July 18, 2019

How to use RMAN in NOARCHIVELOG mode

Hello Friends in this video i'm going to show you how to use take rman backup if your database is running in noarchivelog mode.





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How to Resolve RMAN-06149: cannot BACKUP DATABASE in NOARCHIVELOG mode.







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