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Search found 148 results on 6 pages for 'subqueries'.

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• Can a PL/pgSQL function contain a dynamic subquery?

  - by morpheous

  I am writing a PL/pgSQL function. The function has input parameters which specify (indirectly), which tables to read filtering information from. The function embeds business logic which allows it to select data from different tables based on the input arguments. The function dynamically builds a subquery which returns filtering data which is then used to run the main query. My questions are: Is it 'legal' to use a dynamic subquery in a PL/pgSQL function. I cant see why not - but this question is related to the next one. AFAIK, PL/pgSQL are cached or precompiled by the query engine. How does having a function that generates dynamic subqueries impact the work of the query engine?

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• Simple MySQL Query taking 45 seconds (Gets a record and its "latest" child record)

  - by Brian Lacy

  I have a query which gets a customer and the latest transaction for that customer. Currently this query takes over 45 seconds for 1000 records. This is especially problematic because the script itself may need to be executed as frequently as once per minute! I believe using subqueries may be the answer, but I've had trouble constructing it to actually give me the results I need. SELECT customer.CustID, customer.leadid, customer.Email, customer.FirstName, customer.LastName, transaction.*, MAX(transaction.TransDate) AS LastTransDate FROM customer INNER JOIN transaction ON transaction.CustID = customer.CustID WHERE customer.Email = '".$email."' GROUP BY customer.CustID ORDER BY LastTransDate LIMIT 1000 I really need to get this figured out ASAP. Any help would be greatly appreciated!

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• Write subquery in Criteria of nHibernate.

  - by Bipul

  I read about subquery in Criteria, but I am still unable to grasp it properly. So, here I am taking one example and if somebody can help me writing that using subquery it will be great. Lets say we have table Employee{EmployeeId.(int),Name(string),Post(string),No_Of_years_working(int)} Now I want all the employees who are Managers and working for less than 10 years. I know that we can get the result without using subqueries but I wanna use subquery just to understand how it works in criteria. So, how I can write Criteria using subquery to get those employees. Thanks

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• Multiple many-to-many JOINs in a single mysql query without Cartesian Product

  - by VWD

  At the moment I can get the results I need with two seperate SELECT statements SELECT COUNT(rl.refBiblioID) FROM biblioList bl LEFT JOIN refList rl ON bl.biblioID = rl.biblioID GROUP BY bl.biblioID SELECT GROUP_CONCAT( CONCAT_WS( ':', al.lastName, al.firstName ) ORDER BY al.authorID ) FROM biblioList bl LEFT JOIN biblio_author ba ON ba.biblioID = bl.biblioID JOIN authorList al ON al.authorID = ba.authorID GROUP BY bl.biblioID Combining them like this however SELECT GROUP_CONCAT( CONCAT_WS( ':', al.lastName, al.firstName ) ORDER BY al.authorID ), COUNT(rl.refBiblioID) FROM biblioList bl LEFT JOIN biblio_author ba ON ba.biblioID = bl.biblioID JOIN authorList al ON al.authorID = ba.authorID LEFT JOIN refList rl ON bl.biblioID = rl.biblioID GROUP BY bl.biblioID causes the author result column to have duplicate names. How can I get the desired results from one SELECT statement without using DISTINCT? With subqueries?

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• mysql filtering result using left outer join

  - by user288178

  my query: SELECT content.*, activity_log.content_id FROM content LEFT JOIN activity_log ON content.id = activity_log.content_id AND sess_id = '$sess_id' WHERE activity_log.content_id IS NULL AND visibility = $visibility AND content.reported < ".REPORTED_LIMIT." AND content.file_ready = 1 LIMIT 1 The purpose of that query is to get 1 row from the content table that has not been viewed by the user (identified by session_id), but it still returns contents that have been viewed. What is wrong? ( I have checked the table making sure that the content_ids are there) Note: I think this is more efficient than using subqueries, thoughts?

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• Showing all rows for keys with more than one row

  - by Leif Neland

  Table kal id integer primary key init char 4 indexed job char4 id init job --+----+------ 1 | aa | job1 2 | aa | job2 3 | bb | job1 4 | cc | job3 5 | cc | job5 I want to show all rows where init has more than one row id init job --+----+------ 1 | aa | job1 2 | aa | job2 4 | cc | job3 5 | cc | job5 I tried select * from kal where init in (select init from kal group by init having count(init)2); Actually, the table has 60000 rows, and the query was count(init)<40, but it takes humongus time, phpmyadmin and my patience runs out. Both select init from kal group by init having count(init)2) and select * from kal where init in ('aa','bb','cc') runs in "no time", less than 0.02 seconds. I've tried different subqueries, but all takes "infinite" time, more than a few minutes; I've actually never let them finish. Leif

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• MYSQL - How to increment fields in one row with values from another row

  - by Walker Boh

  I have a table that we'll call 'Sales' with 4 rows: uid, date, count and amount. I want to increment the count and amount values for one row with the count/amount values from a different row in that table. Example: UID | Date | Count | Amount| 1 | 2013-06-20 | 1 | 500 | 2 | 2013-06-24 | 2 | 1000 | Ideal results would be uid 2's count/amount values being incremented by uid 1's values: UID | Date | Count | Amount| 1 | 2013-06-20 | 1 | 500 | 2 | 2013-06-24 | 3 | 1500 | Please note that my company's database is an older version of MYSQL (3.something) so subqueries are not possible. I am curious to know if this is possible outside of doing an "update sales set count = count + 1" and likewise for the amount columns. I have a lot of rows to update and incrementing the values individually is quite time consuming if you can imagine. Thanks for any help or suggestions!

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• how to debug a query that has valid syntax, executes, but returns no results?

  - by Ty W

  So I'm writing a fairly involved query with a half dozen joins, a dependent subquery for [greatest-n-per-group] purposes, grouping, etc. It is syntactically valid, but I've clearly made at least one mistake because it returns nothing. In the past I've debugged valid queries that return nothing by removing joins, executing subqueries on their own, removing WHERE conditions, and removing grouping to see what I would get but so far this one has me stumped. Are there better tools or techniques to use for this sort of thing? This particular query is for MySQL if it matters for any platform-specific tools.

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• NHibernate FetchMode

  - by Sandra

  Hi All, I have an object Parent which has a list of Children: class Parent {Id, Name, IList children} class Child {Id, Name} I need to select all parents where there is a condition for their children but I do not want to get duplicate rows (don't want the children details to appear in select list) Here is the code: session.CreateCriteria(typeof(Parent)) .SetFetchMode("children", FetchMode.Select); .CreateCriteria("children").Add(Subqueries.PropertyIn("Id", {1,2,3,4})) .List(); The query adds all proprties of child class to select list which results in duplicate Parents. Is there any way I can select all parents without having the child details in the select list? Thanks

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• list all likes to a certain post coming from my friends

  - by Max Favilli

  I know I can get posts (paginated, 25 at times) of a certain user with this: https://graph.facebook.com/575128756/posts And the likes of a certain post (paginated, 25 at times) with this GRAPH api call (I omit the first part of the url): /575128756_176517292390301/likes But if I want to get the likes from friends of the post user only? FQL could be an alternative (from table like and subqueries for friend and stream), but FQL seems so buggy in my tests I don't feel comfortable using it in a productive system. Is there anyway to achieve my target using the GRAPH api?

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• Access is re-writing - and breaking - my query!

  - by FrustratedWithFormsDesigner

  I have a query in MS Access (2003) that makes use of a subquery. The subquery part looks like this: ...FROM (SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123") AS q1,... And when I switch to Table View to verify the results, all is OK. Then, I wanted the result of this query to be printed on the page header for a report (the query returns a single row that is page-header stuff). I get an error because the query is suddenly re-written as: ...FROM [SELECT id, dt, details FROM all_recs WHERE def_cd="ABC-00123"; ] AS q1,... So it's Ok that the round brackets are automatically replaced by square brackets, Access feels it needs to do that, fine! But why is it adding the ; into the subquery, which causes it to fail? I suppose I could just create new query objects for these subqueries, but it seems a little silly that I should have to do that.

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• Is there a way to split the results of a select query into two equal halfs?

  - by Matthias

  I'd like to have a query returning two ResultSets each of which holding exactly half of all records matching a certain criteria. I tried using TOP 50 PERCENT in conjunction with an Order By but if the number of records in the table is odd, one record will show up in both resultsets. Example: I've got a simple table with TheID (PK) and TheValue fields (varchar(10)) and 5 records. Skip the where clause for now. SELECT TOP 50 PERCENT * FROM TheTable ORDER BY TheID asc results in the selected id's 1,2,3 SELECT TOP 50 PERCENT * FROM TheTable ORDER BY TheID desc results in the selected id's 3,4,5 3 is a dup. In real life of course the queries are fairly complicated with a ton of where clauses and subqueries.

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• Is it possible with dynamic TSQL query ?

  - by eugeneK

  I have very long select query which i need to filter based on some params, i'm trying to avoid having different stored procedures or if statements inside of single stored procedure by using partly dynamic TSQL... I will avoid long select just for example sake select a from b where c=@c or d=@d @c and @d are filter params, only one can filter at the same time but also both filters could be disabled. 0 for each of these means param is disables so i can create nvarchar with where statement in it... How do i integrate in here dynamic query so 'where' can be added to normal query. I cannot add all the query as big nvarchar because there is too many things in it which will require changes ( ie. when's, subqueries, joins)

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• how do I do this UPDATE in sqlite?

  - by Jason S

  I have a table assoc containing columns local_id, remote_id, cachedData I can successfully run an SQLITE query that looks like SELECT a1.local_id, a1.remote_id FROM assoc a1 LEFT JOIN .... so that I identify certain rows of the assoc table that meet my criteria. What I would like to do is to set cachedData to null in those rows. How can I do this? Sqlite doesn't support UPDATE with joins; you can issue subqueries but I can't figure out how to get the syntax correct; it seems nonintuitive to me.

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• T-SQL Self Join in combination with aggregate function

  - by Nick

  Hi, i have the following table. CREATE TABLE [dbo].[Tree]( [AutoID] [int] IDENTITY(1,1) NOT NULL, [Category] [varchar](10) NULL, [Condition] [varchar](10) NULL, [Description] [varchar](50) NULL, CONSTRAINT [PK_Tree] PRIMARY KEY CLUSTERED ( [AutoID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO the data looks like this: INSERT INTO [Test].[dbo].[Tree] ([Category] ,[Condition] ,[Description]) VALUES ('1','Alpha','Type 1') INSERT INTO [Test].[dbo].[Tree] ([Category] ,[Condition] ,[Description]) VALUES ('1','Alpha','Type 1') INSERT INTO [Test].[dbo].[Tree] ([Category] ,[Condition] ,[Description]) VALUES ('2','Alpha','Type 2') INSERT INTO [Test].[dbo].[Tree] ([Category] ,[Condition] ,[Description]) VALUES ('2','Alpha','Type 2') go I try now to do the following: SELECT Category,COUNT(*) as CategoryCount FROM Tree where Condition = 'Alpha' group by Category but i wish also to get the Description for each Element. I tried several subqueries, self joins etc. i always come to the problem that the subquery cannot return more than one record. The problem is caused by a poor database design which i cannot change and i run out of ideas to get this done in a single query ;-(

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• Core Data not-reverse relationship subquery

  - by user561485

  Hi, I have the following entities in CoreData: Village - villageID Bookmark - (relation) village There are multiple villages with each an unique villageID. I have a entity Bookmark which only has a relation to a Village entity; it isn't possible to make a reverse relation. Now I would like to get the village entities where there exists a Bookmark relation. I've red something about subqueries, but I can't get it right for this situation. It must be something like: Village.villageID IN (Bookmark.village.villageID) It isn't possible to get first all the Bookmarks and then loop to get all the Villages, because of the design of the framework. Can this be done in CoreData (I presume the answer is "Yes, of course!") and how?

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• How do you make long SQL invoked from other code readable?

  - by Artem

  This is a very open question, but I think it can be very beneficial for SQL readability. So you have a Java program, and you are trying to call a monster SQL statement from it, with many subqueries and joins. The starting point for my question is a string constant like this: static string MONSTER_STATEMENT = "SELECT " + " fields" + "WHERE "+ " fieldA = (SELECT a FROM TableC) " + "AND fieldB IN (%s)" + "AND fieldC = %d " + "FROM " " tableA INNER JOIN tableB ON ..."; It later gets filled using String.format and executed. What are you tricks for making this kind of stuff readable? Do you separate your inner joins. Do you indent the SQL itself inside the string? Where do you put the comments? Please share all of the tricks in your arsenal.

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• Mysql question about UPDATE

  - by Beck

  UPDATE counter_reports SET `counter`=`counter`+1,`date`=? WHERE report_id IN( (SELECT report_id FROM counter_reports WHERE report_name="emails_sent" AND `year`=1 ORDER BY report_id DESC LIMIT 1), (SELECT report_id FROM counter_reports WHERE report_name="emails_sent" AND `month`=1 ORDER BY report_id DESC LIMIT 1), (SELECT report_id FROM counter_reports WHERE report_name="emails_sent" AND `week`=1 ORDER BY report_id DESC LIMIT 1), (SELECT report_id FROM counter_reports WHERE report_name="emails_sent" AND `day`=1 ORDER BY report_id DESC LIMIT 1) ) Is there any alternative for such sql? I need to update(increment by 1) last counter reports for day,week,month and year. If I'm adding manually, sql works fine, but with subqueries it fails to launch. Thanks. :)

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• How can an SQL query return data from multiple tables

  - by Fluffeh

  I would like to know how to get data from multiple tables in my database, what types of methods are there to do this, what are joins and unions and how are they different from one another? When should I use each one compared to the others? I am planning to use this in my (for example - PHP) application, but don't want to run multiple queries against the database, what options do I have to get data from multiple tables in a single query? Note: I am writing this as I would like to be able to link to a well written guide on the numerous questions that I constantly come across in the PHP queue, so I can link to this for further detail when I post an answer. The answers cover off the following: Part 1 - Joins and Unions Part 2 - Subqueries Part 3 - Tricks and Efficient Code

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• Beginner SQL question(s)

  - by unit

  I am two months in to an intro sql course, it's late at night, and I am drawing a blank. I have two tables, one customers, and one orders. I have to increase any customers credit limit by twenty five percent for all customers who have made two or more orders in which each order is more than the amount of 250.00. I get how to UPDATE CreditLimit * 1.25 and Cust with an order 250, but how the hell do I get it to check if they have made two orders over 250? Second question, we are just starting to take subqueries, and I am having a difficult time getting it into my skull. Another question posed by the prof of our class is to increase the credit limit of a customer who has an order that exceeds their credit limit. (Credit limit is on a customers table, order and amount are on an orders table). I then take that customer and UPDATE his CreditLimit +1000. Thanks for any help.

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• SQL Server 2008 Web VS SQL Server 2008 Enterprise

  - by Jeremy

  I wrote an application a few months ago, and was hosting it out of our offices on a workstation with an Intel Core 2 Quad Q8200 @ 2.33GHz, 8 GB RAM, Windows Server 2008 Enterprise and SQL Server 2008 Enterprise. Both the webserver and database server were run on the same machine. We had a huge influx in traffic, and moved ClubUptime.com, and got 2 of their top teir windows VMs. The Database server runs Windows 2008 R2 Standard and SQL Server 2008 R2 Web on 8 GB ram and an Intel Xeon e5620 @ 2.40GHz. Ever since switching, the database which used to run at around 400MB in RAM now runs at around 4-7GB, and there haven't been any changes to it (other than a couple columns here and there). Our traffic has quadrupled, and our DB is 6 GB on disk, why would SQL server take up 7 GB if the DB is only 6. And why would it be storing the ENTIRE database in memory? Another thing is why growing 4 times in size did the database's memory footprint grow 12 times? Last question: Why does the CPU peg at 100% now where it didn't before? The design is simple, VERY few joins, NO subqueries. I am just at a loss, unless it is the SQL server edition, or the fact that I moved from real hardware to a VM.

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• SQLAuthority News – Public Training Classes In Hyderabad 12-14 May – Microsoft SQL Server 2005/2008

  - by pinaldave

  After successfully delivering many corporate trainings as well as the private training Solid Quality Mentors, India is launching the Public Training in Hyderabad for SQL Server 2008 and SharePoint 2010. This is going to be one of the most unique and one-of-a-kind events in India where Solid Quality Mentors are offering public classes. I will be leading the training on Microsoft SQL Server 2005/2008 Query Optimization & Performance Tuning. This intensive, 3-day course intends to give attendees an in-depth look at Query Optimization and Performance Tuning in SQL Server 2005 and 2008. Designed to prepare SQL Server developers and administrators for a transition into SQL Server 2005 or 2008, the course covers the best practices for a variety of essential tasks in order to maximize the performance. At the end of the course, there would be daily discussions about your real-world problems and find appropriate solutions. Note: Scroll down for course fees, discount, dates and location. Do not forget to take advantage of Discount code ‘SQLAuthority‘. The training premises are very well-equipped as they will be having 1:1 computers. Every participant will be provided with printed course materials. I will pick up your entire lunch tab and we will have lots of SQL talk together. The best participant will receive a special gift at the end of the course. Even though the quality of the material to be delivered together with the course will be of extremely high standard, the course fees are set at a very moderate rate. The fee for the course is INR 14,000/person for the whole 3-day convention. At the rate of 1 USD = 44 INR, this fee converts to less than USD 300. At this rate, it is totally possible to fly from anywhere from the world to India and take the training and still save handsome pocket money. It would be even better if you register using the discount code “SQLAuthority“, for you will instantly get an INR 3000 discount, reducing the total cost of the training to INR 11,000/person for whole 3 days course. This is a onetime offer and will not be available in the future. Please note that there will be a 10.3% service tax on course fees. To register, either send an email to [email protected] or call +91 95940 43399. Feel free to drop me an email at [email protected] for any additional information and clarification. Training Date and Time: May 12-14, 2010 10 AM- 6 PM. Training Venue: Abridge Solutions, #90/B/C/3/1, Ganesh GHR & MSY Plaza, Vittalrao Nagar, Near Image Hospital, Madhapur, Hyderabad – 500 081. The details of the course is as listed below. Day 1 : Strengthen the basics along with SQL Server 2005/2008 New Features Module 01: Subqueries, Ranking Functions, Joins and Set Operations Module 02: Table Expressions Module 03: TOP and APPLY Module 04: SQL Server 2008 Enhancements Day 2: Query Optimization & Performance Tuning 1 Module 05: Logical Query Processing Module 06: Query Tuning Module 07:  Introduction to the Query Processor Module 08:  Review of common query coding which causes poor performance Day 3: Query Optimization & Performance Tuning 2 Module 09:  SQL Server Indexing and index maintenance Module 10:  Plan Guides, query hints, UDFs, and Computed Columns Module 11:  Understanding SQL Server Execution Plans Module 12: Real World Index and Optimization Tips Download the complete PDF brochure. We are also going to have SharePoint 2010 training by Joy Rathnayake on 10-11 May. All the details for discount applies to the same as well. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Training, SQLAuthority News, T SQL, Technology

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• More SQL Smells

  - by Nick Harrison

  Let's continue exploring some of the SQL Smells from Phil's list. He has been putting together. Datatype mis-matches in predicates that rely on implicit conversion.(Plamen Ratchev) This is a great example poking holes in the whole theory of "If it works it's not broken" Queries will this probably will generally work and give the correct response. In fact, without careful analysis, you probably may be completely oblivious that there is even a problem. This subtle little problem will needlessly complicate queries and slow them down regardless of the indexes applied. Consider this example: CREATE TABLE [dbo].[Page](     [PageId] [int] IDENTITY(1,1) NOT NULL,     [Title] [varchar](75) NOT NULL,     [Sequence] [int] NOT NULL,     [ThemeId] [int] NOT NULL,     [CustomCss] [text] NOT NULL,     [CustomScript] [text] NOT NULL,     [PageGroupId] [int] NOT NULL;  CREATE PROCEDURE PageSelectBySequence ( @sequenceMin smallint , @sequenceMax smallint ) AS BEGIN SELECT [PageId] , [Title] , [Sequence] , [ThemeId] , [CustomCss] , [CustomScript] , [PageGroupId] FROM [CMS].[dbo].[Page] WHERE Sequence BETWEEN @sequenceMin AND @SequenceMax END  Note that the Sequence column is defined as int while the sequence parameter is defined as a small int. The problem is that the database may have to do a lot of type conversions to evaluate the query. In some cases, this may even negate the indexes that you have in place. Using Correlated subqueries instead of a join   (Dave_Levy/ Plamen Ratchev) There are two main problems here. The first is a little subjective, since this is a non-standard way of expressing the query, it is harder to understand. The other problem is much more objective and potentially problematic. You are taking much of the control away from the optimizer. Written properly, such a query may well out perform a corresponding query written with traditional joins. More likely than not, performance will degrade. Whenever you assume that you know better than the optimizer, you will most likely be wrong. This is the fundmental problem with any hint. Consider a query like this:  SELECT Page.Title , Page.Sequence , Page.ThemeId , Page.CustomCss , Page.CustomScript , PageEffectParams.Name , PageEffectParams.Value , ( SELECT EffectName FROM dbo.Effect WHERE EffectId = dbo.PageEffects.EffectId ) AS EffectName FROM Page INNER JOIN PageEffect ON Page.PageId = PageEffects.PageId INNER JOIN PageEffectParam ON PageEffects.PageEffectId = PageEffectParams.PageEffectId  This can and should be written as:  SELECT Page.Title , Page.Sequence , Page.ThemeId , Page.CustomCss , Page.CustomScript , PageEffectParams.Name , PageEffectParams.Value , EffectName FROM Page INNER JOIN PageEffect ON Page.PageId = PageEffects.PageId INNER JOIN PageEffectParam ON PageEffects.PageEffectId = PageEffectParams.PageEffectId INNER JOIN dbo.Effect ON dbo.Effects.EffectId = dbo.PageEffects.EffectId  The correlated query may just as easily show up in the where clause. It's not a good idea in the select clause or the where clause. Few or No comments. This one is a bit more complicated and controversial. All comments are not created equal. Some comments are helpful and need to be included. Other comments are not necessary and may indicate a problem. I tend to follow the rule of thumb that comments that explain why are good. Comments that explain how are bad. Many people may be shocked to hear the idea of a bad comment, but hear me out. If a comment is needed to explain what is going on or how it works, the logic is too complex and needs to be simplified. Comments that explain why are good. Comments may explain why the sql is needed are good. Comments that explain where the sql is used are good. Comments that explain how tables are related should not be needed if the sql is well written. If they are needed, you need to consider reworking the sql or simplify your data model. Use of functions in a WHERE clause. (Anil Das) Calling a function in the where clause will often negate the indexing strategy. The function will be called for every record considered. This will often a force a full table scan on the tables affected. Calling a function will not guarantee that there is a full table scan, but there is a good chance that it will. If you find that you often need to write queries using a particular function, you may need to add a column to the table that has the function already applied.

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• PASS Summit 2011 &ndash; Part IV

  - by Tara Kizer

  This is the final blog for my PASS Summit 2011 series.  Well okay, a mini-series, I guess. On the last day of the conference, I attended Keith Elmore’ and Boris Baryshnikov’s (both from Microsoft) “Introducing the Microsoft SQL Server Code Named “Denali” Performance Dashboard Reports, Jeremiah Peschka’s (blog|twitter) “Rewrite your T-SQL for Great Good!”, and Kimberly Tripp’s (blog|twitter) “Isolated Disasters in VLDBs”. Keith and Boris talked about the lifecycle of a session, figuring out the running time and the waiting time.  They pointed out the transient nature of the reports.  You could be drilling into it to uncover a problem, but the session may have ended by the time you’ve drilled all of the way down.  Also, the reports are for troubleshooting live problems and not historical ones.  You can use Management Data Warehouse for historical troubleshooting.  The reports provide similar benefits to the Activity Monitor, however Activity Monitor doesn’t provide context sensitive drill through. One thing I learned in Keith’s and Boris’ session was that the buffer cache hit ratio should really never be below 87% due to the read-ahead mechanism in SQL Server.  When a page is read, it will read the entire extent.  So for every page read, you get 7 more read.  If you need any of those 7 extra pages, well they are already in cache.  I had a lot of fun in Jeremiah’s session about refactoring code plus I learned a lot.  His slides were visually presented in a fun way, which just made for a more upbeat presentation.  Jeremiah says that before you start refactoring, you should look at your system.  Investigate missing or too many indexes, out-of-date statistics, and other areas that could be leading to your code running slow.  He talked about code standards.  He suggested using common abbreviations for aliases instead of one-letter aliases.  I’m a big offender of one-letter aliases, but he makes a good point.  He said that join order does not matter to the optimizer, but it does matter to those who have to read your code.  Now let’s get into refactoring! Eliminate useless things – useless/unneeded joins and columns.  If you don’t need it, get rid of it! Instead of using DISTINCT/JOIN, replace with EXISTS Simplify your conditions; use UNION or better yet UNION ALL instead of OR to avoid a scan and use indexes for each union query Branching logic – instead of IF this, IF that, and on and on…use dynamic SQL (sp_executesql, please!) or use a parameterized query in the application Correlated subqueries – YUCK! Replace with a join Eliminate repeated patterns Last, but certainly not least, was Kimberly’s session.  Kimberly is my favorite speaker.  I attended her two-day pre-conference seminar at PASS Summit 2005 as well as a SQL Immersion Event last December.  Did I mention she’s my favorite speaker?  Okay, enough of that. Kimberly’s session was packed with demos.  I had seen some of it in the SQL Immersion Event, but it was very nice to get a refresher on these, especially since I’ve got a VLDB with some growing pains.  One key takeaway from her session is the idea to use a log shipping solution with a load delay, such as 6, 8, or 24 hours behind the primary.  In the case of say an accidentally dropped table in a VLDB, we could retrieve it from the secondary database rather than waiting an eternity for a restore to complete.  Kimberly let us know that in SQL Server 2012 (it finally has a name!), online rebuilds are supported even if there are LOB columns in your table.  This will simplify custom code that intelligently figures out if an online rebuild is possible. There was actually one last time slot for sessions that day, but I had an airplane to catch and my kids to see!

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• SQL SERVER – Last Two Days to Get FREE Book – Joes 2 Pros Certification 70-433

  - by pinaldave

  Earlier this week we announced that we will be giving away FREE SQL Wait Stats book to everybody who will get SQL Server Joes 2 Pros Combo Kit. We had a fantastic response to the contest. We got an overwhelming response to the offer. We knew there would be a great response but we want to honestly say thank you to all of you for making it happen. Rick and I want to make sure that we express our special thanks to all of you who are reading our books. The offer is still on and there are two more days to avail this offer. We want to make sure that everybody who buys our most selling combo kits, we will send our other most popular SQL Wait Stats book. Please read all the details of the offer here. The books are great resources for anyone who wants to learn SQL Server from fundamentals and eventually go on the certification path of 70-433. Exam 70-433 contains following important subject and the book covers the subject of fundamental. If you are taking the exam or not taking the exam – this book is for every SQL Developer to learn the subject from fundamentals.  Create and alter tables. Create and alter views. Create and alter indexes. Create and modify constraints. Implement data types. Implement partitioning solutions. Create and alter stored procedures. Create and alter user-defined functions (UDFs). Create and alter DML triggers. Create and alter DDL triggers. Create and deploy CLR-based objects. Implement error handling. Manage transactions. Query data by using SELECT statements. Modify data by using INSERT, UPDATE, and DELETE statements. Return data by using the OUTPUT clause. Modify data by using MERGE statements. Implement aggregate queries. Combine datasets. INTERSECT, EXCEPT Implement subqueries. Implement CTE (common table expression) queries. Apply ranking functions. Control execution plans. Manage international considerations. Integrate Database Mail. Implement full-text search. Implement scripts by using Windows PowerShell and SQL Server Management Objects (SMOs). Implement Service Broker solutions. Track data changes. Data capture Retrieve relational data as XML. Transform XML data into relational data. Manage XML data. Capture execution plans. Collect output from the Database Engine Tuning Advisor. Collect information from system metadata. Availability of Book USA - Amazon | India - Flipkart | Indiaplaza Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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