Search Results

Search found 7 results on 1 pages for 'pemdas'.

Page 1/1 | 1 

  • SQL SERVER – Basic Calculation and PEMDAS Order of Operation

    - by pinaldave
    After thinking a long time, I have decided to write about this blog post. I had no plan to create a blog post about this subject but the amount of conversation this one has created on my Facebook page, I decided to bring up a few of the question and concerns discussed on the Facebook page. There are more than 10,000 comments here so far. There are lots of discussion about what should be the answer. Well, as far as I can tell there is a big debate going on on Facebook, for educational purpose you should go ahead and read some of the comments. They are very interesting and for sure teach some new stuff. Even though some of the comments are clearly wrong they have made some good points and I believe it for sure develops some logic. Here is my take on this subject. I believe the answer is 9 as I follow PEMDAS  Order of Operation. PEMDAS stands for  parentheses, exponents, multiplication, division, addition, subtraction. PEMDAS is commonly known as BODMAS in India. BODMAS stands for Brackets, Orders (ie Powers and Square Roots, etc), Division, Multiplication,  Addition and Subtraction. PEMDAS and BODMAS are almost same and both of them follow the operation order from LEFT to RIGHT. Let us try to simplify above statement using the PEMDAS or BODMAS (whatever you prefer to call). Step 1: 6 ÷ 2 (1+2) (parentheses first) Step 2: = 6 ÷ 2 * (1+2) (adding multiplication sign for further clarification) Step 3: = 6 ÷ 2* (3) (single digit in parentheses – simplify using operator) Step 4: = 6 ÷ 2 * 3 (Remember next Operation should be LEFT to RIGHT) Step 5: = 3 * 3 (because 6 ÷ 2 = 3; remember LEFT to RIGHT) Step 6: = 9 (final answer) Some often find Step 4 confusing and often ended up multiplying 2 and 3 resulting Step 5 to be 6 ÷ 6, this is incorrect because in this case we did not follow the order of LEFT to RIGHT. When we do not follow the order of operation from LEFT to RIGHT we end up with the answer 1 which is incorrect. Let us see what SQL Server returns as a result. I executed following statement in SQL Server Management Studio SELECT 6/2*(1+2) It is clear that SQL Server also thinks that the answer should be 9. Let us go ahead and ask Google what will be the answer of above question in Google I have searched for the following term: 6/2(1+2) The result also says the answer should be 9. If you want a further reference here is a great video which describes why the answer should be 9 and not 1. And here is a fantastic conversation on Google Groups. Well, now what is your take on this subject? You are welcome to share constructive feedback and your answer may be different from my answer. NOTE: A healthy conversation about this subject is indeed encouraged but if there is a single bad word or comment is flaming it will be deleted without any notification (it does not matter how valuable information it contains). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Defensive Programming Techniques.

    - by Pemdas
    I was attempting to identify an element of software engineering that I think is overlooked, not emphasized or not taught in typical undergraduate course work for CS or SE. What I came up is the concept of defensive programing. I would like to hear the communities options on defensive program and/or specific techniques that you use on a regular basis. Also, I would to know if there are any language specific techniques.

    Read the article

  • What features are helpful when performing remote debugging / diagnostics?

    - by Pemdas
    Obviously, the easiest way to solve a bug is to be able to reproduce it in-house. However, sometimes that is not practical. For starters, users are often not very good at providing you with useful information. Customer Service: "what seems to be the issue?" User: "It crashed!" To further compound that, sometimes the bug only occurs under certain environmentally conditions that can not be adequately replicated in-house. With that in mind, it is important to build some sort of diagnostic framework into your product. What types of built-in diagnostic tools have you used or seen used? Logging seems to be the predominate method, which makes sense. We have a fairly sophisticated logging frame work in place with different levels of verbosity and the ability to filter on specific modules (actually we can filter down to the granularity of a single file). Error logs are placed strategically to manufacture a pretty good representation of a stack trace when an error occurs. We don't have the luxury of 10 million terabytes of disk space since I work on embedded platforms, so we have two ways of getting them off the system: a serial port and a syslog server. However, an issue we run into sometimes is actually getting the user to turn the logs on. Our current framework often requires some user interaction.

    Read the article

  • Remote Debugging

    - by Pemdas
    Obviously, the easiest way to solve a bug is to be able to reproduce it in house. However, sometimes that is not practical. For starters, users are often not very good at providing you with useful information. Costumer Service: "what seems to be the issue?" User: "It crashed!" To further compound that, sometimes the bug only occurs under certain environmentally conditions that can not be adequately replicated in house. With that in mind, it is important to build some sort of diagnostic framework into your product. What type of solutions have you seen or used in your experience? Logging seems to be the predominate method, which makes sense. We have a fairly sophisticated logging frame work in place with different levels of verbosity and the ability to filter on specific modules (actually we can filter down to the granularity of a single file). Error logs are placed strategically to manufacture a pretty good representation of a stack trace when an error occurs. We don't have the luxury of 10 million terabytes of disk space since I work on embedded platforms, so we have two ways of getting them off the system: a serial port and a syslog server. However, an issue we run into sometimes is actually getting the user to turn the logs on. Our current framework often requires some user interaction.

    Read the article

  • Interview Questions [closed]

    - by Pemdas
    Possible Duplicate: What techniques do you use when interviewing developers? Nearly every SE interviewing process has some sort of coding exercise to prove that the interviewee can actually write code. More often then not, the exercise also hopes to demonstrate that the interviewee can solve problems. However, this is often not sufficient enough to determine if the interviewee can actually design software. What are some effective ways to determine if an interviewee understands the basic concepts of design such as abstraction, interface design, thread management, ...ect?

    Read the article

  • What environmental factors do you believe contribute to productivity?

    - by Pemdas
    From the perspective of a developer what do you consider to be the most important environmental factors or work place perks/policies that contribute to increase productivity? For example, my top four includes the following: No internet restrictions - Because honestly ever few hours I need a 15 min deload, which usually involves checking my gmail account and or browsing a few choice site. Personal office with a door - for obvious reasons Dual monitors - do people really develop software with one monitor still? Flexible hours - This could be interpreted in different ways, but basically I really appreciate that fact that I can roll into work at 7am, 11am or whenever and the time police aren't on my back. It is just understood that I will put in my 8 hours or more if needed and get my job done however that works out.

    Read the article

  • SQL SERVER – Weekly Series – Memory Lane – #048

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Order of Result Set of SELECT Statement on Clustered Indexed Table When ORDER BY is Not Used Above theory is true in most of the cases. However SQL Server does not use that logic when returning the resultset. SQL Server always returns the resultset which it can return fastest.In most of the cases the resultset which can be returned fastest is the resultset which is returned using clustered index. Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT One of the Jr. Developer asked me this question (What will be the Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT?) while I was rushing to an important meeting. I was getting late so I asked him to talk with his Application Tech Lead. When I came back from meeting both of them were looking for me. They said they are confused. I quickly wrote down following example for them. 2008 SQL SERVER – Guidelines and Coding Standards Complete List Download Coding standards and guidelines are very important for any developer on the path of a successful career. A coding standard is a set of guidelines, rules and regulations on how to write code. Coding standards should be flexible enough or should take care of the situation where they should not prevent best practices for coding. They are basically the guidelines that one should follow for better understanding. Download Guidelines and Coding Standards complete List Download Get Answer in Float When Dividing of Two Integer Many times we have requirements of some calculations amongst different fields in Tables. One of the software developers here was trying to calculate some fields having integer values and divide it which gave incorrect results in integer where accurate results including decimals was expected. Puzzle – Computed Columns Datatype Explanation SQL Server automatically does a cast to the data type having the highest precedence. So the result of INT and INT will be INT, but INT and FLOAT will be FLOAT because FLOAT has a higher precedence. If you want a different data type, you need to do an EXPLICIT cast. Renaming SP is Not Good Idea – Renaming Stored Procedure Does Not Update sys.procedures I have written many articles about renaming a tables, columns and procedures SQL SERVER – How to Rename a Column Name or Table Name, here I found something interesting about renaming the stored procedures and felt like sharing it with you all. The interesting fact is that when we rename a stored procedure using SP_Rename command, the Stored Procedure is successfully renamed. But when we try to test the procedure using sp_helptext, the procedure will be having the old name instead of new names. 2009 Insert Values of Stored Procedure in Table – Use Table Valued Function It is clear from the result set that , where I have converted stored procedure logic into the table valued function, is much better in terms of logic as it saves a large number of operations. However, this option should be used carefully. The performance of the stored procedure is “usually” better than that of functions. Interesting Observation – Index on Index View Used in Similar Query Recently, I was working on an optimization project for one of the largest organizations. While working on one of the queries, we came across a very interesting observation. We found that there was a query on the base table and when the query was run, it used the index, which did not exist in the base table. On careful examination, we found that the query was using the index that was on another view. This was very interesting as I have personally never experienced a scenario like this. In simple words, “Query on the base table can use the index created on the indexed view of the same base table.” Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries Working with SQL Server has never seemed to be monotonous – no matter how long one has worked with it. Quite often, I come across some excellent comments that I feel like acknowledging them as blog posts. Recently, I wrote an article on SQL SERVER – Execution Plan and Results of Aggregate Concatenation Queries Depend Upon Expression Location, which is well received in the community. 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 2011 Startup Parameters Easy to Configure If you are a regular reader of this blog, you must be aware that I have written about SQL Server Denali recently. Here is the quickest way to reach into the screen where we can change the startup parameters. Go to SQL Server Configuration Manager >> SQL Server Services >> Right Click on the Server >> Properties >> Startup Parameters 2012 Validating Unique Columnname Across Whole Database I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. For example “Our business requirement is when we add new column we want it unique across current database.” Read the solution to this strange request in this blog post. Excel Losing Decimal Values When Value Pasted from SSMS ResultSet It is very common when users are coping the resultset to Excel, the floating point or decimals are missed. The solution is very much simple and it requires a small adjustment in the Excel. By default Excel is very smart and when it detects the value which is getting pasted is numeric it changes the column format to accommodate that. Basic Calculation and PEMDAS Order of Operation Read this interesting blog post for fantastic conversation about the subject. Copy Column Headers from Resultset – SQL in Sixty Seconds #027 – Video http://www.youtube.com/watch?v=x_-3tLqTRv0 Delete From Multiple Table – Update Multiple Table in Single Statement There are two questions which I get every single day multiple times. In my gmail, I have created standard canned reply for them. Let us see the questions here. I want to delete from multiple table in a single statement how will I do it? I want to update multiple table in a single statement how will I do it? Read the answer in the blog post. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

1