Digital Signature

A digital signature is a mathematical technique which is used to validate the authenticity and integrity of a message, software or digital document. It is equivalent to handwritten signature or stamped seal, but it offers more security.

In many countries, including United States of America, digital signatures are considered as a legal signature. Indian law has recognized electronic signature or e-signature, under the Information Technology Act, 2000 (IT Act) for over 18 years

Types of Digital signature:

1. Simple
2. Basic
3. Advanced & Qualified

Simple: A simple digital signature doesn’t follow any encryption method. Here, the example is Email signature which we put at the bottom of every email.

There are several disadvantages of this method like unable to recognize user’s identity or changes that happened in a file after a document signed. This type of signature can be easily duplicated.

Basic: Basic digital signatures are almost similar to simple one except that it shows the changes that occurred after the document signed. However, this signature also cannot guarantee the security of the identity. Although, using the Asymmetric Cryptography method, the service providers do not verify the user’s identity.

Advanced & Qualified:  This type of signature is considered as the safest one legal too. It has all the features available in simple and basic along with two-way factor authentication. Using this signature, we can find out the user identity which is important in case of any fraud. The authentication method used also varies: sending one time passwords via SMS, to biometric scanning on mobile phones.

How Digital Signature Work

The digital signature consists of two keys i.e., private and public which based on asymmetric encryption. Here, the private key is used to create a digital signature and the public key is for verifying the digital signature.

For creating a digital signature, we need to take message or file and run it through Hash function. Then combine the result with private key and run it again through a signing algorithm like RSA (Rivest-Shamir-Adleman) or DSA (Digital Signature Algorithm) and as a result we found a digital signature.

The last step is to verification of the signature, so we need a public key to authenticate it. The public key is used to extract the message which was originally combined with the private key to produce the digital signature. The retrieved messaged is now compared with the recipient’s own generated hash value with the extracted message. If both values are equal, then it mean that integrity of the message has been preserved else the secret key used for signing wasn’t this public key’s pair.

Digital Signature Process Illustration

Advantages and Disadvantages

Advantages:

Speed: Digital signatures are speedy comparatively to traditional signatures. Here, we need not to wait for any paper documents to send by courier.

Costs: There is no cost involved with digital signatures in terms of document, postal charges etc.

Security: The use of digital signature reduces the risk of documents being intercepted, read, destroyed or altered while in transit.

Tracking: A digitally signed documents can easily be tracked in a short amount of time.

Disadvantages:

Certificates & Software: To use digital signature, both sender and receiver have to buy a digital certificates\software from trusted certification authorities.

Law: In some countries, cyber law regarding the digital certificates are weak and it may be a risk.

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Happy Learning!!!

SQL Server 2022 – An Introduction

SQL Server 2022 – An Introduction

(Azure-enabled, with continued performance & security innovation)

SQL Server 2022 public review is available now and it is having more features related with Azure. It is the part of the Microsoft Intelligent Data Platform, which unifies operational databases, analytics and data governance.

Top Features:

1. Azure Synapse link for SQL
2. Link feature for Azure SQL Managed Instance
3. Intelligent Query Processing enhancement
4. Query Store
5. Security Enhancements
6. Contained Availability Groups
7. Data lake virtualization and object storage

Azure Synapse Link for SQL

This feature provides near real time analytics, hybrid transactional and analytical processing with minimal impact on operational systems.

Nowadays, there is less requirement of ETL and ELT pipelines due to cost and time consumption and instead of that Microsoft has launched this Synapse Link which can help us in replicating the data from SQL based operational stores to Azure Synapse Analytics.

Link feature for Azure SQL Managed Instance

          Link feature is a new option to connect the Azure SQL Managed Instance with SQL Server hosted anywhere. Here, with an approach that uses near real time data replication to Azure using Always On technology, you can offload workloads to read only secondary on Azure to take advantage of a fully managed database platform, performance and scale. The link can be used as long as we need it and get all the modern benefits of Azure today without migrating to the cloud.

Intelligent Query Processing enhancement

          There is a big enhancement with query processing e.g., Parameter Sensitive Plan. Here, parameter sensitive plan optimization automatically enables multiple active cached plans for a single parameterized statement. Cached execution plans accommodate largely different data sizes based on the customer provided runtime parameter value.

Query Store

          Query store feature was first introduced in SQL Server 2016 and provides the ability for DBA to gain insights on query plan. Now , in SQL Server 2022, it is enabled by default for all newly created SQL Server databases to help customer better track performance history, troubleshoot query plan related issues and enable new query processor capabilities.

Security Enhancements

          There are several improvements which have been implemented in SQL Server 2022 to provide strong security to the products to save customer data. So, SQL Server 2022 include Azure Active Directory authentication, support for richer queries in Always Encrypted, backing up and restoring certificates using the PFX format etc. In addition, there is an improvement with tempdb contention which is completely addressed, and system page latch concurrency has been added to eliminate GAM and SGAM.

Contained Availability Group

          There is a new option contained which consists system databases (Master & MSDB) at the availability group introduced. The feature supports managing objects (users, logins, permissions, agent jobs etc.) at the availability group level and helps us in replicating it within the database replicas.

Data lake virtualization & object storage

          SQL Server 2022 introduces new object storage integration to the data platform, enabling you to integrate SQL Server with S3-compatible object storage, in addition to Azure Storage.

Data Lake virtualization integrates PolyBase with S3-compatible object storage, using the S3 REST API.

Note

SQL Server Evaluation edition is free download and available for 180 days. Please click on this link (https://info.microsoft.com/ww-landing-sql-server-2022.html) to proceed to download.

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Azure Migration program for the organizations in India

I am writing this blog to aware organizations and their representative for Azure migration and FastTrack program announced by Microsoft in recent time. There are two programs which will help organizations to make a cloud journey step by step with the help of Microsoft’s specialist and its concerned teams.

These programs are named as Azure Migration Program and FastTrack for Azure.

Both programs have been designed for the organizations in India to accelerate their digital transformation and cloud journey with business-tailored guidance and support directly from our engineering teams.

Programs Benefits:

1. Step-by step trainings directly from Microsoft and cloud migration specialized partners.
2. Microsoft will provide free Azure migration tools before, during and after migration
3. Microsoft’s support availability for the organizations

To get more insights about this programs, please click on the below links:

Azure Migration Program: https://azure.microsoft.com/en-in/migration/migration-program/

FastTrack for Azure: https://azure.microsoft.com/en-us/programs/azure-fasttrack/#overview

https://forms.gle/sL34NGWhKFxDiKDw6

Top 25 Acronym related to cloud computing

AZURE –Microsoft Azure, formerly known as Windows Azure, is Microsoft’s cloud computing platform. There is no full form of AZURE available.

AWS – Amazon Web Services

GCP– Google Cloud Professional

IaaS – Infrastructure-as-a-Service

PaaS -Platform-as- a-Service

SaaS – Software-as-a-Service

BYOC – Bring Your Own Cloud

CI – Continuous Integration

COA – Cloud Oriented Architecture

DaaS – Desktop as a Service

DBaaS – Database as a Service

DNS – Domain Name Server

EC2 – Amazon Elastic Compute Cloud

EFS – Elastic File System

IoT – Internet of Things

JSON – JavaScript Object Notation

ML – Machine Learning

RDS – Relational Database Services

S3 – Amazon Simple Storage Service

SSD – Solid State Drive

SSH – Secure Shell

VDI – Virtual Desktop Infrastructure

VM – Virtual Machine

VPC – Virtual Private Cloud

VPN – Virtual Private Network

DBA Classes

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To click on below link to register yourself if interested for offline\online classes.

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Facts about SQL Elastic Pool in Azure – (Interview Q & A)

Facts about SQL Elastic Pool in Azure 

(Interview Q & A)

SQL Elastic Pool

This service comes under Database in Azure. Elastic pool works for SQL Databases, it is a simple, cost-effective solution for managing and scaling multiple databases which have varying and unpredictable usage demands.

Elastic Pool is a collection of databases with a shared set of resources managed via a SQL Database Server.

Elastic pool contains multiple databases which reside on a single server and share a fixed number of resources at a set price.

 Important Points

There is no per-database charge for elastic pools. You are billed for each hour a pool exists at the highest eDTU or vCores, regardless of usage or whether the pool was active for less than an hour.

Elastic pools enable the developer to purchase resources for a pool shared by multiple databases to accommodate unpredictable periods of usage by individual databases. Resources configuration can be done based either on the DTU-based purchasing model or the vCore-based purchasing model.

Within the pool, individual databases are given the flexibility to auto-scale within set parameters. Under heavy load, a database can consume more resources to meet demand. Databases under light loads consume less, and databases under no load consume no resources. Additional resources can be added to an existing pool with minimum downtime. Similarly, if extra resources are no longer needed they can be removed from an existing pool at any point in time. And you can add or remove databases from the pool. If a database is predictably under-utilizing resources, move it out.

When moving databases into or out of an elastic pool, there is no downtime except for a brief period of time (on the order of seconds) at the end of the operation when database connections are dropped.

Benefits

1.The more databases you can add to a pool the greater your savings become. Depending on your application utilization pattern, it’s possible to see savings with as few as two S3 databases.

2. A single database can be moved in and out of an elastic pool, which gives us flexibility.

3. Elastic pools in Azure SQL Database enable SaaS developers to optimize the price performance for a group of databases within a prescribed budget while delivering performance elasticity for each database.

When a database can join Pool

A database should be considered for a pool when its peak utilization is about 1.5 times greater than its average utilization.

DTU-based purchasing model example An S3 database that peaks to 100 DTUs and on average uses 67 DTUs or less is a good candidate for sharing eDTUs in a pool. Alternatively, an S1 database that peaks to 20 DTUs and on average uses 13 DTUs or less is a good candidate for a pool.

Business continuity options for databases in an elastic pool

Pooled databases generally support the same business continuity features that are available to single databases.

Point-in-time restore

Point-in-time restore uses automatic database backups to recover a database in a pool to a specific point in time.

Geo-restore

Geo-restore provides the default recovery option when a database is unavailable because of an incident in the region where the database is hosted

Active geo-replication

For applications that have more aggressive recovery requirements than geo-restore can offer

Creating a new SQL Database elastic pool using the Azure portal

Two ways to create:

1. All services >> Databases >> SQL Elastic Pools
2. Or you can create an elastic pool by navigating to an existing server and clicking + New poolto create a pool directly into that server.

 Important Point

You can create multiple pools on a server, but you can’t add databases from different servers into the same pool.

Pre-requisite to create Elastic Pool:

1. Subscription
2. Resource Group
3. Elastic Pool Name
4. Server
5. Compute + Storage

Interview Q & A based on Elastic Pool

1. What is an eDTU?

eDTU stands for the elastic Data Throughput Unit. It is a unit used to measure several counters like CPU, Memory, disk read, writes and other similar counters related to performance. With eDTUs, you can measure the performance offered by the different options

2. What is the difference between DTU and vCore?

With the DTU model you pay one fixed price for your compute (or IO/memory), as well as your data storage and back up retention. With the vCore model you have separate charges for your compute (what type of node or compute power you’re using) and a separate charge for your storage.

3. What components the DTU of Azure SQL consists of?

The DTU model is based on the Database Transaction Unit, and is a blended mix of CPU, I/O and memory (RAM) capabilities based on a benchmark OLTP workload called ASDB. The vCore model is based on the number of virtual CPU cores you require, and this can be scaled up as your workload increases

4. What is public IP and Private IP in Azure?

Public IP addresses allow Internet resources to communicate inbound to Azure resources. Public IP addresses enable Azure resources to communicate to Internet and public-facing Azure services. … A resource without a public IP assigned can communicate outbound

5. What will happen when SQL Azure database will reach the max size?

If the SQL Azure database will reach the max size, data read or fetch operations will still work on it but create, insert or update operations will stop with it. You can choose to drop, delete or truncate the data in this condition.

https://docs.google.com/forms/d/e/1FAIpQLSdQ8y7cpqlcR4PyCNOGFRYJ2bp0dNFb25GykncrHKbKDZLJwQ/viewform?embedded=true“>http://

Cloud Computing – Lockdown (COVID 19) A trouble or an opportunity to move into MS CLOUD

 

Hope, you all are doing good during this pandemic while working from home. Really, it is tough time to meet out colleagues’ friends, relatives and families. We miss each and every moment of office e.g. tea time, lunch, dinner, one-one meeting, discussions, presentations etc. However, missing all these things but still I think this is the precious time for our learning through digital ways.  there are several ways to enhance our knowledge and gain experience while at home.

This is specially for our DBA friends who are working on premises or who are learning Database technology so I would recommend that they need to take a step ahead and wonder into the cloud.

Of course, I am talking about cloud computing. As, there are several cloud vendors available with the Cloud technologies, so we need not to waste our time and learn something named cloud computing as it is the huge demand of the market now-a-days.

What is cloud Computing ?.

 

Popular Cloud Vendors

1. Microsoft Azure
2. Amazon Web Services (AWS)
3. Google Cloud
4. Alibaba Cloud
5. IBM Cloud
6. Oracle

Services Offered by Cloud Providers

All these providers are providing multiple services in the form of

1. IAAS (Infrastructure as a service)
2. PAAS (Platform as a service)
3. SAAS (Software as a service)

How to learn MS Azure

1. Simple create an account on Microsoft Azure site ( https://portal.azure.com/#home)
2. User your any credit card and it will deduct only Rs.2 which is refundable
3. Microsoft will give you 30 days free services for learning purpose
4. Start learning after creating your account
5. User services through Market place on the portal

Note: Different cloud providers provide different free time duration on their website.

From the point view of database, we need to learn database services in the cloud. We can support database in two ways in Azure

1. SQL Server in Azure Virtual Machine (IAAS)
2. SQL Database (PAAS)

For the first point, we need to create a virtual machine first just like we do work on premise and then work on SQL Server.

However, SQL Database is in built service in Azure and we can directly work on the same by connecting to Azure portal.

I have written other blogs previously on such stuff, please go through the same for more details (How to learn Microsoft Cloud- Azure) & (Introduction to Microsoft Azure)

Summary: From this blog, I have tried to provoke my friends to go out and have a journey into MS cloud which will be fruitful in future. A lot of free cloud stuff is available on MS website and on Google so move and learn something new and enhance the knowledge.

Happy Learning!

 

 

 

SQL Server Error 8942 – Know The Reasons and Solution of This Problem

Summary: In this article, I am going to tell you the reasons behind the problem SQL server error 8942 also we will discuss the step by step procedure to resolve this issue. But for this, the user has to read this article carefully. So without consuming much time lets start.

Microsoft SQL Server is a highly featured rich and result oriented application. Most of the organization use this software to store and handle important business data in the form of tables. This application stores the data in MDF ( primary database file), PDF ( Secondary database file) and LDF log file. But sometimes due to lack of knowledge and improper handling of SQL Server the SQL users have to face an unknown error SQL Server Error 8942.

Server: Msg 8942, Level 16, State 1 Table error: Object ID O_ID, index ID I_ID, page P_ID. Test (TEST) failed. Slot S_ID, offset 0xADDRESS overlaps with the prior row.

So in the forthcoming article, We are going to discuss the possible reasons for this problem and also we will discuss the procedure to resolve this issue easily.

Possible Reason Behind SQL Server Error 8942

Here the common causes of this error. Some of which are described below

1. In case of Overlapping of Slots – The offset of the next slot must be greater than the previous slot. If the offset slot S_ID is not greater or equal than the previous slot then the user has to face this error.

2. Hardware Malfunction– Sometimes due to hardware malfunction can also lead to SQL Server Error 8942 error.

3. Improper Shutdown of SQL Server – Improperly or forceful closure of the SQL Server will also lead to this problem.

As we have seen the reason for the above problem the user can try the DBCC CHECKDB command without using the repair clause. But in case if you won’t be able to resolve this error then the user can take the help of an Expert solution to resolve this problem. 

Note: The user can also read another post to Restore SQL database. 

Automated Method to Recover SQL Database If You Are Facing SQL Server Error 8942

The user can try the manual solution to tackle this problem. But this includes the high possibility of data loss situation. So, in that case, the user can try the SQL database recovery software to resolve this issue. This can easily repair the corrupted and damaged SQL recovery software. This is an efficient recovery tool that can easily recover SQL tables, stored procedures, indexes, functions, triggers, etc. For complete details and Working of this software, the user can try the free version of SQL database recovery software to recover SQL database. 

 

Steps to Recover Crucial SQL Database

1. Launch the SQL Database Recovery Software from your system

2. Now select the Corrupted MDF file from your system.

3. Choose the Scan mode from Quick Scan and Advanced Scan. The user can click on preview deleted SQL Records in red color.

4. Click on the OK button. The tool will show the complete preview of SQL database objects.

5. Now Click on the Export button and select the Server name and authentication type.

6. The user can select the database or the user can export to the Existing database.

7. Select the database items you want to recover.

8. Select the option from With schema and data.

9. Now click on the Export button to start the process.

Final Words

In this article, we have discussed the step by step process to SQL Server Error 8942. We have given the reasons for the above error. The manual process has so many limitations so in that case, the user can try the SQL Recovery Software to tackle this problem.

Perform SQL Server Deleted Data Recovery in a Simplified Way

Many times SQL server database users have to face disastrous situations. Sometimes users perform delete operation in the database without having any backup of the data. Due to this misoperation, the database administrators have to face lots of issues.
If you have also deleted the data accidentally and you do not have the recent backup available or your backup file is corrupted or unreadable. Then in this blog, we will discuss how to perform SQL server deleted data recovery easily.

As we know that the user may have to face data loss situation at any time due to several known and unknown reasons. And also sometimes many tables and other components of the database turns into the unreadable state. Let us understand the problem with the help of query asked by the SQL users in the forum site.

“Hi to all! One of My Colleague has accidentally deleted 1000 records from a table named Y (id int, name varchar (20), salary int). Now is there have any way to perform SQL server deleted data recovery easily. I do not have the recent backup of the database. Please help me to get back my data.”

Here are The Requirements to Perform SQL Server Deleted Data Recovery

1. Make sure SQL Server is installed on your machine
2. SQL Server Management Studio is installed.
3. SysTools SQL Database Recovery tool is Required to recover deleted records from SQL database.

Perform SQL Server Deleted Data Recovery by Using Trusted Solution 

To recover deleted records from SQL database the user can take the help of trusted and reliable solution SysTools SQL Database Recovery tool. This is advanced software which can easily recover all the database objects such as tables, stored procedure, functions, etc. This software can easily repair the corrupt MDF and NDF file data. Moreover, this utility comes with easy to use user interface so that everyone can easily use this software with ease. Also this software is compatible with SQL server 2017, 2016, 2014, 2012, 2008 / 2008R2, 2005, 2000 database files.

Follow the Steps to Perform SQL Server Deleted Data Recovery Process

1. Download and Install the Software on your machine.
2. Now click on open and browse the MDF file from its location.
3. After that select the Scan Mode from the Quick Scan and Advanced Scan.
4. Select the SQL server version and if you don’t know the version then choose auto-detect SQL server file.
5. In the database, authentication selects the server name and the authentication mode.
6. Select the destination process by creating a new database or exporting to the existing database.
7. Now you have to click on the checkbox to export the desired components of the database.
8. choose the export option from with only schema and schema and data.
9. Finally, click on Export option to start the export process.

Note: Please make sure to check the checkbox export deleted records option.

Also: The user can another similar post how to recover deleted records in SQL server

Summing Up

In this article, we have discussed how to perform SQL server deleted data recovery. We have resolved the problem faced by the users how to recover deleted records from SQL table by using SQL recovery software. This software has easy to use, simple user interface so that the user can easily use this software to recover deleted database objects.

 

 

SQL DBA Interview Q & A on Stretch Database

Introduction to Stretch Database in Azure

There are different databases and services are available in Microsoft Azure.  Here, I am going to focus on stretch database/feature which is available from SQL Server 2016 onward.

Different types of databases & services in Azure

1. Azure Cache for Redshift
2. Azure Cosmos DB
3. Azure Data Explorer
4. Azure Database for Maria DB
5. Azure Database for MySQL
6. Azure SQL Database
7. Azure database for PostgreSQL
8. Data Factory
9. SQL Data Warehouse
10. SQL Server Stretch Database
11. Table Storage

SQL Server Stretch Database:

This feature allows us to stretch our database to Azure for warm and cold transactional data. We can provide longer retention times. It saves our cost around 40% less expensive than adding more enterprise storage.

Stretch database bills compute and storage separately. Compute usage is represented with Database Stretch Unit (DSU), customer can scale up and down the level of performance/DSUs they need at any time.

Here, Database sizes are limited to 240 TB.

This picture shows how to enable the Stretch feature and use it to save our cold data to Azure.

Interview Q &A

1.What editions of SQL Server are compatible with Stretch Database?

Stretch Database is a feature of SQL Server 2016. It is available on all editions of SQL Server 2016.

2.Can I change the performance level of my Stretch Database?

You can adjust the performance level of your Stretch Database. Changing performance levels takes a matter of minutes and your databases are online and available during the change.

3.What is a DSU (Database Stretch Unit)?

A SQL Stretch Database Stretch Unit (DSU) represents the power of the query and is quantified by workload objectives: how fast rows are written, read and computed against. This measure helps customers assess the relative amount of performance needed for their workload.

4.How much data can I stretch to Azure?

You can stretch up to 240 TB of data with Stretch Database.

5.How can I un-stretch my database?

You can move your data back to the on-premises environment at any time. If you decide to unsubscribe from Stretch Database, you must move data back on premises via un-stretching or export to a storage service in order to retain access to the data.

Note: Egress charges apply for data moving out of Azure. For more information on un-stretch or exporting data, please see the SQL Server 2016 Stretch Database documentation.

6.How much storage will my databases consume?

You will consume approximately the same amount of storage in Stretch Database as you currently do in SQL Server as the data originally stored in SQL Server is moved to Stretch Database.

7.Can I stretch to another SQL Server instead of Stretch Database?

Stretch Database currently does not support stretching to another SQL Server. You cannot stretch a SQL Server database to another SQL Server database.

8.If I have an existing Stretch database from SQL Server 2016 RC0 or earlier, can I just upgrade RC1 or later and run on the new Stretch Database service?

Direct upgrade is not supported. If you need to retain data already stretched to Azure, you will need to first un-migrate the data from Azure to your SQL Server database. Upon completion, you can upgrade and re-stretch to the new Stretch Database service. Please note that un-migrating data from Azure will incur data egress charges. If you are on RC1 or later, you may upgrade to a newer version using any existing upgrade methods supported by SQL Server.

9.How can I stretch to a SQL Stretch database?

You will need to first un-migrate the data from Azure back to your SQL Server database. Upon completion, you can upgrade and re-stretch to the new Stretch Database service. Please note that un-migrating data from Azure will incur data egress charges.

Microsoft Azure Sentinel

Today’s demand is how to protect the organization and its data from the cyber threat because data is most important things for any organization. As companies are moving to Cloud therefore some cloud based technology is needed to work on that. To keep it as an important area, Microsoft has announced two cloud-based technologies named as:

1. Microsoft Azure Sentinel
2. Microsoft Threat Experts

Azure Sentinel enables us to protect our entire organization by letting us see and stop threats before they cause harm. As Sentinel is built on Azure so we can take advantage of limitless cloud speed and scale and invest our time in security.

Azure sentinel supports open standards such as common event format and broad partner connections, including Microsoft Intelligent Security Association partners such as Check Point, Cisco, F5, Fortinet, Palo Alto Networks and Symantec etc. Azure Sentinel is available in preview today from the Azure portal.

As this is a new technology and it is in preview in Azure therefore to learn more please explore to Microsoft website.

https://news.microsoft.com/en-in/