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SQL Server 2016 Hosting - HostForLIFE.eu :: TRIM Function In SQL Server 2017

clock February 20, 2019 10:22 by author Peter

With the release of SQL Server 2017, a new TRIM() is also introduced which helps to remove the white space/characters from both sides of a string. Before 2017, this functionality was achieved by using the following SQL functions.
    REPLACE - used o replace a character from a string
    LTRIM - trim the white spaces from the left side of a string
    RTRIM - trim the white spaces from the right side of a string

I can explain the functionality with two scenarios.

Let's assume, we have a string named ' ABC ' and we are going to eliminate the white spaces from both sides of the string.
 
In SQL, we usually use the LTRIM and RTRIM function like in the code below.
    SELECT LTRIM( RTRIM(' ABC ')) 

Now, this can be done by using a single TRIM function.
    SELECT TRIM(' ABC ') 

Test results from SSMS can be seen below.

Assume we have a string named 'X ABC Y' and we need to extract 'ABC' from that. As usual, we will go with the REPLACE function as follows.
    SELECT REPLACE(REPLACE('X ABC Y','X ',''),' Y','') 

Here you go with the TRIM function.
    SELECT TRIM('XY ' FROM 'X ABC Y') 

Test results from SSMS are shown below.

Note - It is necessary that you have to mention the trailing charter in the TRIM function, otherwise, this will not work as expected.
 
For example, if you try to remove the 'white space' only from the string 'X  ABC  Y', then TRIM will not help you. Similarly,  if you don't mention the letter 'Y', TRIM will not remove the white space after the string, even though you already mentioned the 'X' and the 'white space' characters inside the TRIM function. See these scenarios in the below screenshot.
 
Test results from SSMS,

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AngularJS Hosting - HostForLIFE.eu :: AES Encryption/Decryption With Angular 7

clock February 15, 2019 10:15 by author Peter

Most of the time, a developer requires encryption and decryption for encoding a message or information in such a way that only authorized person can retrieve that information.
In this article, I will discuss the implementation of AES encryption and decryption with Angular 7 while developing an application.

So, the first question that comes in our mind is "What is AES?".
AES stands for "Advanced Encryption Standard".
It is a tool that is used to encrypt and decrypt the simple text using AES encryption algorithm.
This algorithm was developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen.
AES was designed to be efficient in both, hardware and software, and supports a block length of 128 bits and key lengths of 128, 192, and 256 bits.

When to use AES Encryption

When you want to encrypt a confidential text into a decryptable format, for example - when you need to send some sensitive data in an e-mail.
The decryption of the encrypted text is possible only if you know the right password.

Now, try to implement the AES encryption and decryption in Angular 7. It's very easy to implement in Angular 7 with the help of crypto-js.

First, we create a new project with the following command.
ng new EncryptionDescryptionSample 

After that, install crypto.js file, by the following command.
npm install crypto-js --save 

For better UI, we also install bootstrap by the following command.
npm install bootstrap --save 

After running the above command, check the package.json file if it is installed or not. Your file should look like this.
AES Encryption/Decryption with Angular 7

Now, go to "app.component.html" file and replace the existing code with the below code.
<h1 class="text-center">Encrypt-Decrypt with AES</h1> 
 
<br> 
<div> 
  <div class="row"> 
    <div class="col-sm-6"> 
      <button type="button" class="btn btn-primary btn-lg btn-block"> 
        Encryption 
      </button> 
      <br> 
      <div class="form-group"> 
        <label for="txtTextToConvert">Plain Text</label> 
        <input type="text" class="form-control" placeholder="Enter text you want to encrypt" [(ngModel)]="plainText"> 
      </div> 
 
      <div class="form-group"> 
        <label for="txtPassword">Password</label> 
        <input type="password" class="form-control" placeholder="Enter encryption password" [(ngModel)]="encPassword"> 
      </div> 
      <textarea class="form-control" readonly rows="3">{{conversionEncryptOutput}}</textarea> 
      <br> 
      <button type="button" class="btn btn-success float-right" (click)="convertText('encrypt')">Encrypt</button> 
    </div> 
    <div class="col-sm-6"> 
      <button type="button" class="btn btn-dark btn-lg btn-block"> 
        Decryption 
      </button> 
      <br> 
      <div class="form-group"> 
        <label for="txtTextToConvert">Encrypted Text</label> 
        <input type="text" class="form-control" placeholder="Enter text you want to decrypt" [(ngModel)]="encryptText"> 
      </div> 
 
      <div class="form-group"> 
        <label for="txtPassword">Password</label> 
        <input type="password" class="form-control" placeholder="Enter decryption password" [(ngModel)]="decPassword"> 
      </div> 
      <textarea class="form-control" readonly rows="3">{{conversionDecryptOutput}}</textarea> 
      <br> 
      <button type="button" class="btn btn-success float-right" (click)="convertText('decrypt')">Decrypt</button> 
    </div> 
  </div> 
</div> 


Now, visit "app.component.ts" file and write the below code,
import { Component } from '@angular/core'; 
import * as CryptoJS from 'crypto-js'; 
 
@Component({ 
  selector: 'app-root', 
  templateUrl: './app.component.html', 
  styleUrls: ['./app.component.css'] 
}) 
export class AppComponent { 
  title = 'EncryptionDecryptionSample'; 
   
  plainText:string; 
  encryptText: string; 
  encPassword: string; 
  decPassword:string; 
  conversionEncryptOutput: string; 
  conversionDecryptOutput:string; 
   
  constructor() { 
  } 
  //method is used to encrypt and decrypt the text 
  convertText(conversion:string) { 
      if (conversion=="encrypt") { 
        this.conversionEncryptOutput = CryptoJS.AES.encrypt(this.plainText.trim(), this.encPassword.trim()).toString(); 
      } 
      else { 
        this.conversionDecryptOutput = CryptoJS.AES.decrypt(this.encryptText.trim(), this.decPassword.trim()).toString(CryptoJS.enc.Utf8); 
      
    } 
  } 


In the above code, we used the Encrypt method of AES and passed our plain text with a password to encrypt the string. Similarly, we used the Decrypt method of AES and passed our encrypted text with a password to decrypt the string. Be sure that both times, your password is the same. For using both of these methods, you need to import "CryptoJS" from crypto-js.
import * as CryptoJS from 'crypto-js'; 

Now, let us run the project by using the following command.
ng serve --o 

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SQL Server 2016 Hosting - HostForLIFE.eu :: Brief Introduction To Indexes In SQL Server

clock February 12, 2019 10:42 by author Peter

If you want to find a record in a table without having an index, the system will scan the whole table to get that record. Well, this is a very costly operation in terms of time. For example, if your table has 10 million records, it will scan all these records to find the value. To overcome this problem, indexes are used. Indexes use the B-TREE search algorithm to search a record in a table, which is way faster than the table scan.

Types of Index
Below are the frequently used types of Indexes.

  • Clustered Index
    A clustered index is an index that defines the physical order of records to be stored in a table. Therefore, the table can have only one clustered index. 
  • Non-Clustered Index
    A non-clustered index is similar to an index in a book. The data is stored in one place and the index is stored in another place. Here, the index has pointers to the storage location of the data. Therefore, a table can have more than one Non-clustered index. 
The syntax for creating an index.
CREATE INDEX <Index Name>  
ON <Table Name> (<Column Name>);  
  
/*Example of creating index on Lastname column of Persons table*/  
  
CREATE INDEX idx_lastname  
ON Persons (LastName); 

Benefits of indexing foreign key columns

There are two primary benefits of using the Index on foreign key.
  1. Makes delete operation of parent table faster
    When you delete a row from a parent table, the SQL Server checks if there are any rows which reference the row being deleted in the child table. To find the rows efficiently, an index on the foreign key column is extremely useful.
  2. Making joins faster
    Using Index, SQL Server can more effectively find the rows to join to when the child and parent tables are joined.

Can we have multiple indexes on the same column?

  • As you can have only one clustered index per table, you cannot have multiple clustered indexes on the same column; however, you can have multiple non-clustered indices on the same column.

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SQL Server 2017 Hosting :: How to Know that Your SQL Server Eat too Much Memory?

clock January 29, 2019 08:14 by author Scott

Sounds impossible, right? The saying goes that you can never be too rich or too thin or have too much memory.

However, there is one good indication that your SQL Server is probably overprovisioned, and to explain it, I need to cover 3 metrics.

1. Max Server Memory is set at the instance level: right-click on your SQL Server name in SSMS, click Properties, Memory, and it’s “Maximum server memory.” This is how much memory you’re willing to let the engine use. (The rocket surgeons in the audience are desperate for the chance to raise their hands to point out different things that are or aren’t included in max memory – hold that thought. That’s a different blog post.)

2. Target Server Memory is how much memory the engine is willing to use. You can track this with the Perfmon counter SQLServer:Memory Manager – Target Server Memory (KB):

SELECT *
FROM sys.dm_os_performance_counters
WHERE counter_name LIKE '%Target Server%';

Generally, when you start up SQL Server, the target is set at your max. However, SQL Server doesn’t allocate all of that memory by default. (Again, the experts wanna raise hands and prove how much they know – zip it.)

3. Total Server Memory is roughly how much the engine is actually using. (Neckbeards – seriously – zip it until the end of the post. I’m not playing.) After startup, SQL Server will gradually use more and more memory as your queries require it. Scan a big index? SQL Server will start caching as much of that index as it can in memory. You’ll see this number increase over time until – generally speaking – it matches target server memory.

SELECT *
FROM sys.dm_os_performance_counters
WHERE counter_name LIKE '%Total Server%';

What if Total Server Memory doesn’t go up?

Say you have a SQL Server with:

  • 64GB memory
  • Max memory set to 60GB
  • 1GB of total database size (just to pick an extreme example)

Infrequent query workloads (we don’t have hundreds of users trying to sort the database’s biggest table simultaneously, or do cartesian joins)

SQL Server might just not ever need the memory.

And in a situation like this, after a restart, you’ll see Total Server Memory go up to 2-3GB and call it a day. It never rises up to 10GB, let alone 60GB. That means this SQL Server just has more memory than it needs.

Here’s an example of a server that was restarted several days ago, and still hasn’t used 4GB of its 85GB max memory setting. Here, I’m not showing max memory – just the OS in the VM, and target and total:



In most cases, it’s not quite that black-and-white, but you can still use the speed at which Total Server Memory rises after a reboot to get a rough indication of how badly (and quickly) SQL Server needs that memory. If it goes up to Target Server Memory within a couple of hours, yep, you want that memory bad. But if it takes days? Maybe memory isn’t this server’s biggest challenge.

Exceptions obviously apply – for example, you might have an accounting server that only sees its busiest activity during close of business periods. Its memory needs might be very strong then, but not such a big deal the rest of the month.



SQL Server 2016 Hosting - HostForLIFE.eu :: How to Scheduling Things To Run In SQL Server?

clock January 23, 2019 10:21 by author Peter

A key part of the SQL Server Agent is the ability to schedule jobs. While you can create one schedule for each agent job, frequently with applications like Reporting Services, users use Shared Schedules across multiple jobs. For instance, you can set a schedule to run at 8 am on week days or run every 2 hours or pick from a predefined list of schedules that already exist in the MSDB database. These are very convenient. However, if you choose to use these be sure you are keeping track of what is running for each of these shared schedules. You should not have everything running at once.

This is an example of a job schedule in a Management Studio SQL Server Agent Job. You can create a new one or pick from a list of already made schedules.

There’s nothing inherently wrong with using shared schedules—some very small operations can all run at the same time, however when you start to use them for larger operations you can really impact the overall performance of your server.

Many times, I have seen high CPU or locks as well as many other performance issues due to the system being overloaded with jobs running on shared schedules or all at the same time (midnight is a frequently common choice). Not every report to should run at 8 am and every data load run every 2 hours. If you not using shared schedules or added a separate schedule per job it is also important to make sure you are not running up against other things running. If you are using applications like SSRS, then you need to pay attention to when the report subscription refreshes are happening. Don’t overload your system by having everything run at once. Job and subscription schedules need to be analyzed and evaluated just like everything else you care for in your database.

To keep this from happening consult your agent jobs to see what other jobs are running before scheduling additional ones. You can easily get a glimpse in Job activity monitor to see what’s running and when it will run next.

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AngularJS Hosting - HostForLIFE.eu :: How to Create Cascading Dropdown in AngularJS?

clock January 16, 2019 11:50 by author Peter

In this post, I will make a Cascading Dropdown in AngularJS. Add 2 Class 1 for Countries and other for state. Write the following code:
public class Country 

    public int CountryId { get; set; } 
    public string CountryName { get; set; } 

public class State 

    public int StateId { get; set; } 
    public string StateName { get; set; } 
    public int CountryId { get; set; } 

Create a ActionResult Name it as Index [Add a View].

Add the script

<script src="~/Scripts/angular.min.js"></script> 

Create a js Name it in my case its CascadingDropdown.

var app = angular.module('myApp', []); 
app.controller('myController', function ($scope, $http) { 
    getcountries(); 
    function getcountries() { 
     
        $http({ 
            method: 'Get', 
            url: '/Home/Countries' 
 
        }).success(function (data, status, header, config) { 
 
            $scope.countries = data; 
        }).error(function (data, status, header, config) { 
            $scope.message = "Error"; 
        }); 
    } 
 
    $scope.GetStates = function ()  
    { 
        var countryIdselected = $scope.countrymodel; 
        if (countryIdselected) { 
            $http({ 
                method: 'Post', 
                url: '/Home/States', 
                data: JSON.stringify({ countryId: countryIdselected }) 
            }).success(function (data, status, header, config) { 
                $scope.states = data; 
            }).error(function (data, status, header, config) { 
                $scope.message = "Error"; 
            }) 
        } 
        else { 
            $scope.states = null; 
        } 
    } 
}); 
 
 
//Calls for Country DropDown 
 public ActionResult Countries() 
        { 
            List<Country> cobj = new List<Country>(); 
            cobj.Add(new Country { CountryId = 1, CountryName = "India" }); 
            cobj.Add(new Country { CountryId = 2, CountryName = "Srilanka" }); 
            cobj.Add(new Country { CountryId = 3, CountryName = "USA" }); 
 
            return Json(cobj, JsonRequestBehavior.AllowGet); 
        } 
 
//Calls for State DropDown with CountryID as Parameter 
 
        public ActionResult States(int countryId) 
        { 
   List<State> sobj = new List<State>(); 
   sobj.Add(new State { StateId = 1, StateName = "Karnataka", CountryId = 1 }); 
   sobj.Add(new State { StateId = 2, StateName = "Kerala", CountryId = 1 }); 
   sobj.Add(new State { StateId = 3, StateName = "TamilNadu", CountryId = 1 }); 
   sobj.Add(new State { StateId = 1, StateName = "Newyork", CountryId = 3 }); 
   sobj.Add(new State { StateId = 1, StateName = "Colombo", CountryId = 2 }); 
 
//Filter based on CountryID 
            var result = sobj.Where(x => x.CountryId == countryId).Select(x => new { x.StateId, x.StateName }); 
 
            return Json(result); 
        } 
 
//IndexView 
//  Add the script file <script src="~/Scripts/CascadingDropdown.js"></script> 
<div ng-app="myApp"> 
       
            <form name="mainForm"  ng-controller="myController"> 
 
                <select ng-model="countrymodel" ng-options=" c.CountryId as c.CountryName for c in countries" ng-change="GetStates()"> 
                    <option value="">-- Select Country --</option> 
                </select> 
                <select ng-model="statemodel" ng-options="s.StateId as s.StateName for s in states "> 
                    <option value="">-- Select State --</option> 
                </select> 
            </form> 
</div>  


I hope it works for you!

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SQL Server 2016 Hosting - HostForLIFE.eu :: ASCII Values Of Alphabets And Numbers In SQL Server

clock January 11, 2019 11:10 by author Peter

To find the ASCII value of an alphabet or a number, we can use ASCII function in SQL Server. We will see how to get the ASCII value of numbers from 0-9 and uppercase and lowercase alphabets.

What is ASCII?
ASCII (American Standard Code for Information Interchange) is the most common format for text files in computers and on the internet. In an ASCII file, each alphabetic, numeric, or special character is represented with a 7-bit binary number (a string of seven 0s or 1s). There can be 128 possible characters defined. It serves as a character encoding standard for modern computers.

Syntax
ASCII ( ‘character_expression’ )

ASCII value of capital A is 65 and Z 90.
    SELECT ASCII('A') 
    SELECT ASCII('Z') 


To find the ASCII values of alphabets from A to Z, use this code.

    DECLARE @Start int 
    set @Start=65 
    while(@Start<=90) 
    begin 
    print char(@Start) 
    set @Start=@Start+1 
    end 


To find the ASCII values of characters from a to z, we can use this query.
    SELECT ASCII('a') 
     
    SELECT ASCII('z') 
     
    DECLARE @Start int 
    set @Start=97 
    while(@Start<=122) 
    begin 
    print char(@Start) 
    set @Start=@Start+1 
    end 

ASCII Values Of Alphabets And Number In SQL Server

To find the ASCII value of numbers from 0 to 9, we can use this query.
    SELECT ASCII(9) 
     
    SELECT ASCII(0) 
     
    DECLARE @Start int 
    set @Start=48 
    while(@Start<=57) 
    begin 
    print char(@Start) 
    set @Start=@Start+1 
    end

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SQL Server 2016 Hosting - HostForLIFE.eu :: APPROX_COUNT_DISTINCT Function In SQL

clock January 7, 2019 11:13 by author Peter

Approximate COUNT DISTINCT

We all have written queries that use COUNT DISTINCT to get the unique number of non-NULL values from a table. This process can generate a noticeable performance hit especially for larger tables with millions of rows. Many times, there is no way around this. To help mitigate this overhead SQL Server 2019 introduces us to approximating the distinct count with the new APPROX_COUNT_DISTINCT function. The function approximates the count within a 2% precision to the actual answer at a fraction of the time.

Let’s see this in action.
In this example, I am using the AdventureworksDW2016CTP3 sample database which you can download here.
    SET STATISTICS IO ON 
    SELECT COUNT(DISTINCT([SalesOrderNumber])) as DISTINCTCOUNT 
    FROM [dbo].[FactResellerSalesXL_PageCompressed] 


SQL Server Execution Times
CPU time = 3828 ms, elapsed time = 14281 ms.
    SELECT APPROX_COUNT_DISTINCT ( [SalesOrderNumber]) as APPROX_DISTINCTCOUNT 
    FROM [dbo].[FactResellerSalesXL_PageCompressed] 


SQL Server Execution Times
CPU time = 7390 ms, elapsed time = 4071 ms.

APPROX_COUNT_DISTINCT Function In SQL

You can see the elapsed time is significantly lower! Great improvement using this new function.

The first time I did this, I did it wrong. A silly typo with a major result difference. So take a moment and learn from my mistake.

Note that I use COUNT(DISTINCT(SalesOrderNumber)) not DISTINCT COUNT (SalesOrderNumber ). This makes all the difference. If you do it wrong, the numbers will be way off as you can see from the below result set. You’ll also find that the APPROX_DISTINCTCOUNT will return much slower than the Distinct Count; which is not expected.

APPROX_COUNT_DISTINCT Function In SQL

Remember COUNT(DISTINCT expression) evaluates the expression for each row in a group and returns the number of unique, non-null values, which is what APPROX_COUNT_DISTINCT does. DISTINCT COUNT (expression) just returns a row count of the expression, there is nothing DISTINCT about it.

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SQL Server 2016 Hosting - HostForLIFE.eu :: SQL Server Development Best Practices Guide

clock December 19, 2018 10:13 by author Peter

Coding is always a fun but challenging job. Developers do not only have to execute the right output based on the business requirement but also need to maintain the right coding standards by using the optimum use of variable sizes and keeping in view the other best practices. I am going to provide a list of best practices and guidelines today, in this article. Many of us already may have been using these but I thought to gather those in a single page so that while developing, the code can be useful, keeping the standard intact.
Application to be used,

  • Developers need to use the Developer Edition of the SQL Server edition rather than using SQL Express or Enterprise edition.

Database Design

  • Ensure that the referential integrity is maintained at all the times, i.e., the relationship between Primary Key and Foreign Key.
  • Always specify the narrowest columns you can. In addition, always choose the smallest data type you need to hold the data you need to store in a column. The narrower the column, the less amount of data SQL Server must store, and the faster SQL Server is able to read and write data.

Database Configuration Settings

  • Create proper database file sizes (this includes Initial DB file size and growth values)
  • Maintaining consistency in DB filegroups across the markets.

Data modeling

  • Use of appropriate data types and length while the data models are created (limit using blob data types unless really needed). The narrower the column, the less amount of data SQL Server must store, and the faster SQL Server is able to read and write data.

Performance/Load Tests

  • While performing perf tests, adjusts the database file sizes accordingly. Suspend the maintenance jobs during the period.

Purging solution

  • Checking with the business team over a period to implement the correct data purging solutions which best fits your environment.

Database Objects

  • Use user-defined constraint names rather using system-generated names.
  • Use database objects to sit in the respective defined Filegroups. Avoid getting the user objects and data to sit in the system/primary filegroup.

Indexing

  • Appropriate Index Naming convention.
  • Appropriate use of Case while creating objects such as tables, indexes and other objects.
  • Use the appropriate column sequence while creating the index schema.
  • Try to avoid creating duplicate indexes.
  • Limit use of filtered indexes unless you are sure that can give you real benefits.
  • When creating a composite index, and when all other considerations are equal, make the most selective column in the first column of the index.
  • keep the “width” of your indexes as narrow as possible. This reduces the size of the index and reduces the number of disks I/O reads required to read the index, boosting performance.
  • Avoid adding a clustered index to a GUID column (unique identifier data type). GUIDs take up 16-bytes of storage, more than an Identify column, which makes the index larger, which increases I/O reads, which can hurt performance.
  • Indexes should be considered on all columns that are frequently accessed by the JOIN, WHERE, ORDER BY, GROUP BY, TOP, and DISTINCT clauses.
  • Don't automatically add indexes on a table because it seems like the right thing to do. Only add indexes if you know that they will be used by queries run against the table. Always assess your workload before creating the right indexes.
  • When creating indexes, try to make them unique indexes if possible. SQL Server can often search through a unique index faster than a non-unique index because in a unique index, each row is unique, and once the needed record is found, SQL Server doesn't have to look any further.

Properties of Indexes

  • Don’t automatically accept the default value of 100 for the fill factor for your indexes. It may or may not best meet your needs. A high fill factor is good for seldom changed data, but highly modified data needs a lower fill factor to reduce page splitting.

Transact-SQL

  • If you perform regular joins between two or more tables in your queries, performance will be optimized if each of the joined columns has appropriate indexes.
  • Don't over-index your OLTP tables, as every index you add increases the time it takes to perform INSERTS, UPDATES, and DELETES. There is a fine line between having the ideal number of indexes (for SELECTs) and the ideal number to minimize the overhead that occurs with indexes during data modifications.
  • If you know that your application will be performing the same query over and over on the same table, consider creating a non-clustered covering index on the table. A covering index, which is a form of a composite index, includes all the columns referenced in SELECT, JOIN, and WHERE clauses of a query. Because of this, the index contains the data you are looking for and SQL Server doesn't have to look up the actual data in the table, reducing I/O, and boosting performance.
  • Remove encryption from table columns where it is not necessary at all. Overuse of encryption can lead to poor performance. Check with business users time to time on this to ensure right table columns are only considered for encryption.

Version control/source control

  • Maintain all code in a source control system and update it always for all type of changes happening to the code base.

Queries and Stored Procedures

  • Keep the transactions as short as possible. This reduces locking and increases the application concurrency, which helps to boost the performance.
  • If needed to run SQL commands use only designated columns rather using * to fetch all the commands and use the TOP operator to limit the number of records.
  • Avoid using query hints unless you know exactly what you are doing, and you have verified that the hint boosts performance. Instead, use the right isolation levels.
  • SET NOCOUNT ON at the beginning of each stored procedure you write.
  • Do not unnecessarily use select statements in the code block if you do not want to send any result back to display.
  • Avoid such code which can lead to unnecessary network calls. Check the count of the code block and verify if those many calls are really needed.
  • When using the UNION statement, keep in mind that, by default, it performs the equivalent of a SELECT DISTINCT on the result set. In other words, UNION takes the results of two like record sets, combines them, and then performs a SELECT DISTINCT in order to eliminate any duplicate rows. This process occurs even if there are no duplicate records in the final recordset. If you know that there are duplicate records, and this presents a problem for your application, then use the UNION statement to eliminate the duplicate rows.
  • If you see there is a necessity to use Upper () or Lower () functions or need to use LTRIM () or RTRIM () functions, it will be better to modify the data corrected while accepting the user inputs from the application side rather performing changes in the script. This will make the queries to run faster.
  • Carefully evaluate whether your SELECT query needs the DISTINCT clause or not. Some developers automatically add this clause to every one of their SELECT statements, even when it is not necessary.
  • In your queries, don't return column data you don't need. For example, you should not use SELECT * to return all the columns from a table if you don't need all the data from every column. In addition, using SELECT * may prevent the use of covering indexes, further potentially hurting query performance.
  • Always include a WHERE clause in your SELECT statement to narrow the number of rows returned. Only return those rows you need.
  • If your application allows users to run queries, but you are unable in your application to easily prevent users from returning hundreds, even thousands of unnecessary rows of data, consider using the TOP operator within the SELECT statement. This way, you can limit how many rows are returned, even if the user doesn't enter any criteria to help reduce the number of rows returned to the client.
  • Try to avoid WHERE clauses that are non-sargable. If a WHERE clause is sargable, this means that it can take advantage of an index (assuming one is available) to speed completion of the query. If a WHERE clause is non-sargable, this means that the WHERE clause (or at least part of it) cannot take advantage of an index, instead of performing a table/index scan, which may cause the query's performance to suffer. Non-sargable search arguments in the WHERE clause, such as "IS NULL", "<>", "!=", "!>", "!<", "NOT", "NOT EXISTS", "NOT IN", "NOT LIKE", and "LIKE '%500'" generally prevents (but not always) the query optimizer from using an index to perform a search. In addition, expressions that include a function on a column, expressions that have the same column on both sides of the operator, or comparisons against a column (not a constant), are not sargable. In such case, break the code appropriately so that a proper index or set of indexes can be used.
  • If using temporary tables to keep the backup of the existing large tables in the database, remove them as and when the task is needed as those contain a lot of storage and the maintenance plan will take more time to complete as because those tables will be considered for maintenance as well.
  • Do not use special characters or use them very carefully while passing them via a stored procedure. It might change the query execution plan and lead to poor performance. Often the situation is known as Parameter sniffing.
  • Avoid SQL server to do an implicit conversion of data, rather use it appropriately (use explicit code-based conversion).

SQL Server CLR
The Common language runtime (CLR) feature allows you to write stored procedures/trigger/functions in .NET managed code and execute the same from SQL Server.

  • Use the CLR to complement Transact-SQL code, not to replace it.
  • Standard data access, such as SELECT, INSERTs, UPDATEs, and DELETEs are best done via Transact-SQL code, not the CLR.
  • Computationally or procedurally intensive business logic can often be encapsulated as functions running in the CLR.
  • Use CLR for error handling, as it is more robust than what Transact-SQL offers.
  • Use CLR for string manipulation, as it is generally faster than using Transact-SQL.
  • Use CLR when you need to take advantage of the large base class library.
  • Use CLR when you want to access external resources, such as the file system, Event Log, a web service, or the registry.
  • Set CLR code access security to the most restrictive permissions as possible.

Consultation

  • You can also a consultant with your in-house DBAs for any advice about Microsoft Best Practices and standard or use of correct indexes to be used.
  • You can seek training from any good external training providers.
  • Another good option is to use good third-party tools such as RedGate, FogLight, Idera, SQLSentry, SolarWinds and check the performance of the environment by monitoring the scripts.

Process Improvement

  • Document common mistakes in the Lessoned Learned page per the PMP best practice guidelines.
  • Do check out the new upcoming editions and try to align your code accordingly.

Hope that the above-advised guidelines would be useful. Do share if you use any other steps in your workplace which is found to be helpful.

HostForLIFE.eu SQL Server 2016 Hosting
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SQL Server 2016 Hosting - HostForLIFE.eu :: Maximum Limit Value For Integer Data Type in SQL Server 2012

clock November 27, 2018 10:12 by author Peter

In this article, I described how to calculate the maximum range of various integer data types in SQL Server. TINYINT, SMALLINT, INT and BIGINT are all number data types. The difference between these data types are in the minimum and maximum values. So let's have a look at a practical example of how to calculate the maximum range of the integer data type in SQL Server. The example is developed in SQL Server 2012 using the SQL Server Management Studio.

Calculating the maximum range of various integer data types.

Bigint Data Type
The Bigint data type represents an integer value. It can be stored in 8 bytes.

Formula   2^(n-1) is the formula of the maximum value of a Bigint data type.
In the preceding formula N is the size of the data type. The ^ operator calculates the power of the value.
Now determine the value of N in Bit:
Select (max_length * 8) as 'Bit(s)' from sys.types Where name = 'BIGInt' 

 

Determine the maximum range of Bigint
The formula is:
2^(n-1) here N=64

Select Power(cast(2 as varchar),(64) -1) as 'Bigint max range'  from sys.types Where name = 'BIGInt'

The range of a Bigint data type is -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

INT Data Type
Int represents an integer value that can be stored in 4 bytes. INT is the short form of integer.

Formula
2^(n-1) is the formula to find the maximum of an INT data type.
In the preceding formula N is the size of data type. The ^ operator calculates the power of the value.

Now determine the value of N in Bit:
Select (max_length * 8) as 'Bit(s)' from sys.types Where name = 'Int'

Determine the maximum range of int
The formula is:
2^(n-1) here N=32
Select Power(cast(2 as varchar),(32) -1) as 'int max range'  from sys.types Where name = 'Int'

The range of an int data type is -2,147,483,648 to 2,147,483,647.

Smallint Data Type
Smallint represents an integer value that can be stored in 2 bytes.

Formula 
2^(n-1) is the formula to find the maximum of a Smallint data type.
In the preceding formula N is the size of the data type. The ^ operator calculates the power of the value.

Now determine the value of N in Bit:Select (max_length * 8) as 'Bit(s)' from sys.types Where name = 'Smallint'

Determine the maximum range of Smallint
The formula is:
2^(n-1) here N=64
Select Power(cast(2 as varchar),(16) -1) as 'Smallint max range'  from sys.types Where name = 'SMALLInt'

The range of a Smallint data type is -32768 to 32767.
Tinyint Data Type
Tinyint represents an integer value that can be stored in 1 byte.
The range of a Tinyint data type is 0 to 255.

HostForLIFE.eu SQL Server 2016 Hosting
HostForLIFE.eu is European Windows Hosting Provider which focuses on Windows Platform only. We deliver on-demand hosting solutions including Shared hosting, Reseller Hosting, Cloud Hosting, Dedicated Servers, and IT as a Service for companies of all sizes.



About HostForLIFE

HostForLIFE is European Windows Hosting Provider which focuses on Windows Platform only. We deliver on-demand hosting solutions including Shared hosting, Reseller Hosting, Cloud Hosting, Dedicated Servers, and IT as a Service for companies of all sizes.

We have offered the latest Windows 2019 Hosting, ASP.NET 5 Hosting, ASP.NET MVC 6 Hosting and SQL 2019 Hosting.


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