Sql Server Slow Upload for Shift Jis

Yesterday, I had asked a very simple question on twitter about the top reasons for the slow functioning. I had received a lot of interesting answers and perspectives on that topic. Lots of people likewise sent me a detailed email as they thought in that location is not enough space to type the answer to the question. Here is the blog postal service which actually I had built based on various comments on twitter and particularly three emails I have received.

Hither is the tweet in the discussion.

Tiresome Performance Tweet

In existent earth… Which resource do you encounter bottlenecking SQL Server Performance?

— Pinal Dave (@pinaldave) February 8, 2020

Wearisome Performance of SQL Server – Poor Architecture

This seems to be the unanimously acme reason for the poor performing SQL Server. Even so, the topic of architecture is very broad and it is incommunicable to discuss every single point of the architecture inefficiency. The topic of architecture spread from indexes to query re-writing and AlwaysOn to a read-only replica, there are infinite things we tin can include under this topic. Even so, here are a few topics that were highlighted during the chat.

It is not easy for anyone to build a time to come proof schema and lawmaking. When nosotros offset our business, the requirement of the business organisation is very different than when we are running the same business for many years. The success of the business organisation likewise brings expansion in different geography and growth of the data which all leads to lots of custom lawmaking and temporary fixes, which becomes permanent. Here is a quick list that leads to the poor performance of the SQL Server.

Reason #ane: Bad Schema Designing

You may find it surprising lots of people start building a schema without fully grasping the requirements and that leads to poor blueprint at the kickoff which leads to very complex queries and terrible server performance.

Here are the mutual mistakes:

• Poor Normalization – Flat broad tables or over normalization
• Redundant data in databases
• Bad referential integrity (foreign keys and constraints)
• Wide composite chief keys (and clustered indexes)
• No stress testing of schema robustness adhering growth patterns

At that place are many more bad schema designing practices, however, many times nosotros only come up across them afterward our business concern has been successful and it is hard to change the schema afterward a while. If you are starting a new project, it is always recommended to accept a proper schema designing from the beginning and follow all the necessary steps of the health check.

Reason #2: Inefficient T-SQL Queries / Code

At that place are and then many reasons for poor coding and most of the time it is considering the programmer who is writing the code is not 100% familiar with the schema or new T-SQL features. I accept seen lots of users using cursors and while loop to insert the data where they can simply insert the data using INSERT…SELECT or SELECT…INTO Table.

Here are the common mistakes:

• Using Non IN or IN instead of NOT EXISTS or EXISTS
• Using cursors or white loop instead of INSERT…SELECT or SELECT…INTO Tabular array
• Using SELECT * instead of only necessary cavalcade names
• Forgetting to apply parenthesis when using logical OR or AND operators
• Nesting of subqueries creating a complex execution plan
• Using functions on Indexed Cavalcade in WHERE clause
• Overuse of scalar user-defined functions
• Datatype mismatch in predicates (where condition or joins)
• Interchanging usage of UNION vs UNION ALL
• Unnecessary using Singled-out everywhere
• Dynamic SQL
• … this tin can be a calendar month-long series

While I talk over this in detail during my Comprehensive Database Functioning Wellness Check, you tin can always sentry my gratis videos discussing this topic here.

Reason #iii: Poor Indexing Strategies

It is so mutual to see people using indexing equally a solution to go out of the jail carte du jour and quite often they end upwardly in jail once again for using the card. Indexing is often considered a silver bullet to solve performance issues but honestly, the story is very different. Indexing can work absolutely against y'all if you using it incorrectly. There are many horror stories along with the indexing. I take blogged a lot well-nigh this topic and then I volition keep the discussion very short.

Hither are the common mistakes:

• Indexing every single strange key
• Indexing every column in the table
• Many single-column indexes
• Preferring Heap Tabular array over the Clustered alphabetize
• Underindexing your table
• Non maintaining your index

Here are two of my most popular scripts for indexing, which tin assistance you to balance your index strategies.

• SQL SERVER – Missing Alphabetize Script – Download
• SQL SERVER – Unused Alphabetize Script – Download

Additionally, I suggest you lot lookout my free video here where I demonstrate how an index tin reduce the functioning of SELECT statements.

Here is the follow-up blog postal service: Poor Indexing Strategies – 10 Don'ts for Indexes.

Reason #iv: Incorrect Server Deployment

This is my favorite topic and as a thing of fact, I can keep on talking about it for hours. If you take attended any of my preparation sessions, you lot must be aware of the listing of incorrect server deployment practices, I discuss during the session. The biggest complaint, I hear when people upgrade their SQL Server is the despite newer software and hardware they are getting poor performance. There are many unlike parameters involved in the tiresome performance of the SQL Server and the biggest one is the proper deployment.

Here are the common mistakes:

• Keeping Maximum Degree of Parallelism to 0
• Not setting the index level to fill cistron
• Lower Filegrwoth
• Single TempDB files
• Hosting SQL Server data and log files together
• Running antivirus on SQL Server files
• Incorrect value in Max Memory Configuration
• Loftier latency for your log files
• … and many more I often discuss during the health check.

Reason #five: Under Provisioned Hardware

I actually wish this was the major problem in the industry. Nearly of the time, I just see over-provisioned hardware but incorrectly deployed SQL Server. Let us see some of the sample questions, I often receive.

• Our CPU is running 100%, should we provide more than CPU?
• Our memory is dislocated 95% by SQL Server, how to keep them free?
• Our disk queue is ever very high, should nosotros add together more disks and a separate workload?

Honestly, you tin can e'er throw more than hardware and improve the functioning but that is never the case, to begin with. Giving more hardware may temporarily solve the problem but that may non be a permanent solution. One should become through a more scientific way to await at how your resources are consumed and based on that brand decision of the hardware.

I have recommended upgrading the hardware in iii out of 100 functioning tuning cases. Most of the time we can solve the wearisome performance issues related to CPU, IO and Retentivity issue the systematic and scientific process of the health check of the server.

Slow Performance and Knowledge

The solution to all the problems is very simple – Cognition. If you are a professional in the data platform area, you must keep on learning and developing yourself to stay alee of all the new upcoming challenges.

If your server is running slow and would like to take a discussion nigh information technology, please do not hesitate to attain out to me for further word almost this topic,Comprehensive Database Performance Wellness Cheque. I will be happy to talk to yous about your server's health and assist you ready information technology up for success .

You can always connect with me on Twitter and LinkedIn.

Reference:Pinal Dave (https://blog.sqlauthority.com)

johnsonwasisange.blogspot.com

Source: https://blog.sqlauthority.com/2020/02/10/sql-server-top-reasons-for-slow-performance/

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