Search Results

Search found 34476 results on 1380 pages for 'sql blog'.

Page 399/1380 | < Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >

• Real tortoises keep it slow and steady. How about the backups?

  - by Maria Zakourdaev

    … Four tortoises were playing in the backyard when they decided they needed hibiscus flower snacks. They pooled their money and sent the smallest tortoise out to fetch the snacks. Two days passed and there was no sign of the tortoise. "You know, she is taking a lot of time", said one of the tortoises. A little voice from just out side the fence said, "If you are going to talk that way about me I won't go." Is it too much to request from the quite expensive 3rd party backup tool to be a way faster than the SQL server native backup? Or at least save a respectable amount of storage by producing a really smaller backup files?  By saying “really smaller”, I mean at least getting a file in half size. After Googling the internet in an attempt to understand what other “sql people” are using for database backups, I see that most people are using one of three tools which are the main players in SQL backup area:  LiteSpeed by Quest SQL Backup by Red Gate SQL Safe by Idera The feedbacks about those tools are truly emotional and happy. However, while reading the forums and blogs I have wondered, is it possible that many are accustomed to using the above tools since SQL 2000 and 2005.  This can easily be understood due to the fact that a 300GB database backup for instance, using regular a SQL 2005 backup statement would have run for about 3 hours and have produced ~150GB file (depending on the content, of course).  Then you take a 3rd party tool which performs the same backup in 30 minutes resulting in a 30GB file leaving you speechless, you run to management persuading them to buy it due to the fact that it is definitely worth the price. In addition to the increased speed and disk space savings you would also get backup file encryption and virtual restore -  features that are still missing from the SQL server. But in case you, as well as me, don’t need these additional features and only want a tool that performs a full backup MUCH faster AND produces a far smaller backup file (like the gain you observed back in SQL 2005 days) you will be quite disappointed. SQL Server backup compression feature has totally changed the market picture. Medium size database. Take a look at the table below, check out how my SQL server 2008 R2 compares to other tools when backing up a 300GB database. It appears that when talking about the backup speed, SQL 2008 R2 compresses and performs backup in similar overall times as all three other tools. 3rd party tools maximum compression level takes twice longer. Backup file gain is not that impressive, except the highest compression levels but the price that you pay is very high cpu load and much longer time. Only SQL Safe by Idera was quite fast with it’s maximum compression level but most of the run time have used 95% cpu on the server. Note that I have used two types of destination storage, SATA 11 disks and FC 53 disks and, obviously, on faster storage have got my backup ready in half time. Looking at the above results, should we spend money, bother with another layer of complexity and software middle-man for the medium sized databases? I’m definitely not going to do so.  Very large database As a next phase of this benchmark, I have moved to a 6 terabyte database which was actually my main backup target. Note, how multiple files usage enables the SQL Server backup operation to use parallel I/O and remarkably increases it’s speed, especially when the backup device is heavily striped. SQL Server supports a maximum of 64 backup devices for a single backup operation but the most speed is gained when using one file per CPU, in the case above 8 files for a 2 Quad CPU server. The impact of additional files is minimal.  However, SQLsafe doesn’t show any speed improvement between 4 files and 8 files. Of course, with such huge databases every half percent of the compression transforms into the noticeable numbers. Saving almost 470GB of space may turn the backup tool into quite valuable purchase. Still, the backup speed and high CPU are the variables that should be taken into the consideration. As for us, the backup speed is more critical than the storage and we cannot allow a production server to sustain 95% cpu for such a long time. Bottomline, 3rd party backup tool developers, we are waiting for some breakthrough release. There are a few unanswered questions, like the restore speed comparison between different tools and the impact of multiple backup files on restore operation. Stay tuned for the next benchmarks.    Benchmark server: SQL Server 2008 R2 sp1 2 Quad CPU Database location: NetApp FC 15K Aggregate 53 discs Backup statements: No matter how good that UI is, we need to run the backup tasks from inside of SQL Server Agent to make sure they are covered by our monitoring systems. I have used extended stored procedures (command line execution also is an option, I haven’t noticed any impact on the backup performance). SQL backup LiteSpeed SQL Backup SQL safe backup database <DBNAME> to disk= '\\<networkpath>\par1.bak' , disk= '\\<networkpath>\par2.bak', disk= '\\<networkpath>\par3.bak' with format, compression EXECUTE master.dbo.xp_backup_database @database = N'<DBName>', @backupname= N'<DBName> full backup', @desc = N'Test', @compressionlevel=8, @filename= N'\\<networkpath>\par1.bak', @filename= N'\\<networkpath>\par2.bak', @filename= N'\\<networkpath>\par3.bak', @init = 1 EXECUTE master.dbo.sqlbackup '-SQL "BACKUP DATABASE <DBNAME> TO DISK= ''\\<networkpath>\par1.sqb'', DISK= ''\\<networkpath>\par2.sqb'', DISK= ''\\<networkpath>\par3.sqb'' WITH DISKRETRYINTERVAL = 30, DISKRETRYCOUNT = 10, COMPRESSION = 4, INIT"' EXECUTE master.dbo.xp_ss_backup @database = 'UCMSDB', @filename = '\\<networkpath>\par1.bak', @backuptype = 'Full', @compressionlevel = 4, @backupfile = '\\<networkpath>\par2.bak', @backupfile = '\\<networkpath>\par3.bak' If you still insist on using 3rd party tools for the backups in your production environment with maximum compression level, you will definitely need to consider limiting cpu usage which will increase the backup operation time even more: RedGate : use THREADPRIORITY option ( values 0 – 6 ) LiteSpeed : use  @throttle ( percentage, like 70%) SQL safe :  the only thing I have found was @Threads option.   Yours, Maria

  Read the article

• Interview with Geoff Bones, developer on SQL Storage Compress

  - by red(at)work

  How did you come to be working at Red Gate? I've been working at Red Gate for nine months; before that I had been at a multinational engineering company. A number of my colleagues had left to work at Red Gate and spoke very highly of it, but I was happy in my role and thought, 'It can't be that great there, surely? They'll be back!' Then one day I visited to catch up them over lunch in the Red Gate canteen. I was so impressed with what I found there, that, three days later, I'd applied for a role as a developer. And how did you get into software development? My first job out of university was working as a systems programmer on IBM mainframes. This was quite a while ago: there was a lot of assembler and loading programs from tape drives and that kind of stuff. I learned a lot about how computers work, and this stood me in good stead when I moved over the development in the 90s. What's the best thing about working as a developer at Red Gate? Where should I start? One of the great things as a developer at Red Gate is the useful feedback and close contact we have with the people who use our products, either directly at trade shows and other events or through information coming through the product managers. The company's whole ethos is built around assisting the user, and this is in big contrast to my previous development roles. We aim to produce tools that people really want to use, that they enjoy using, and, as a developer, this is a great thing to aim for and a great feeling when we get it right. At Red Gate we also try to cut out the things that distract and stop us doing our jobs. As a developer, this means that I can focus on the code and the product I'm working on, knowing that others are doing a first-class job of making sure that the builds are running smoothly and that I'm getting great feedback from the testers. We keep our process light and effective, as we want to produce great software more than we want to produce great audit trails. Tell us a bit about the products you are currently working on. You mean HyperBac? First let me explain a bit about what HyperBac is. At heart it's a compression and encryption technology, but with a few added features that open up a wealth of really exciting possibilities. Right now we have the HyperBac technology in just three products: SQL HyperBac, SQL Virtual Restore and SQL Storage Compress, but we're only starting to develop what it can do. My personal favourite is SQL Virtual Restore; for example, I love the way you can use it to run independent test databases that are all backed by a single compressed backup. I don't think the market yet realises the kind of things you do once you are using these products. On the other hand, the benefits of SQL Storage Compress are straightforward: run your databases but use only 20% of the disk space. Databases are getting larger and larger, and, as they do, so does your ROI. What's a typical day for you? My days are pretty varied. We have our daily team stand-up meeting and then sometimes I will work alone on a current issue, or I'll be pair programming with one of my colleagues. From time to time we give half a day up to future planning with the team, when we look at the long and short term aims for the product and working out the development priorities. I also get to go to conferences and events, which is unusual for a development role and gives me the chance to meet and talk to our customers directly. Have you noticed anything different about developing tools for DBAs rather than other IT kinds of user? It seems to me that DBAs are quite independent minded; they know exactly what the problem they are facing is, and often have a solution in mind before they begin to look for what's on the market. This means that they're likely to cherry-pick tools from a range of vendors, picking the ones that are the best fit for them and that disrupt their environments the least. When I've met with DBAs, I've often been very impressed at their ability to summarise their set up, the issues, the obstacles they face when implementing a tool and their plans for their environment. It's easier to develop products for this audience as they give such a detailed overview of their needs, and I feel I understand their problems.

  Read the article

• How can I use SQL to select duplicate records, along with counts of related items?

  - by mipadi

  I know the title of this question is a bit confusing, so bear with me. :) I have a (MySQL) database with a Person record. A Person also has a slug field. Unfortunately, slug fields are not unique. There are a number of duplicate records, i.e., the records have different IDs but the same first name, last name, and slug. A Person may also have 0 or more associated articles, blog entries, and podcast episodes. If that's confusing, here's a diagram of the structure: I would like to produce a list of records that match this criteria: duplicate records (i.e., same slug field) for people who also have at least 1 article, blog entry, or podcast episode. I have a SQL query that will list all records with the same slug fields: SELECT id, first_name, last_name, slug, COUNT(slug) AS person_records FROM people_person GROUP BY slug HAVING (COUNT(slug) > 1) ORDER BY last_name, first_name, id; But this includes records for people that may not have at least 1 article, blog entry, or podcast. Can I tweak this to fit the second criteria?

  Read the article

• Linq Scope Problem + Reduce Repeated Code

  - by Tom Gullen

  If the parameter is -1, it needs to run a different query as to if an ID was specified... how do I do this? I've tried initialising var q; outside the If block but no luck! // Loads by Entry ID, or if -1, by latest entry private void LoadEntryByID(int EntryID) { IEnumerable<tblBlogEntry> q; if (EntryID == -1) { q = ( from Blog in db.tblBlogEntries orderby Blog.date descending select new { Blog.ID, Blog.title, Blog.entry, Blog.date, Blog.userID, Comments = ( from BlogComments in db.tblBlogComments where BlogComments.blogID == Blog.ID select BlogComments).Count(), Username = ( from Users in db.yaf_Users where Users.UserID == Blog.userID select new { Users.DisplayName }) }).FirstOrDefault(); } else { q = ( from Blog in db.tblBlogEntries where Blog.ID == EntryID select new { Blog.ID, Blog.title, Blog.entry, Blog.date, Blog.userID, Comments = ( from BlogComments in db.tblBlogComments where BlogComments.blogID == Blog.ID select BlogComments).Count(), Username = ( from Users in db.yaf_Users where Users.UserID == Blog.userID select new { Users.DisplayName }) }).SingleOrDefault(); } if (q == null) { this.Loaded = false; } else { this.ID = q.ID; this.Title = q.title; this.Entry = q.entry; this.Date = (DateTime)q.date; this.UserID = (int)q.userID; this.Loaded = true; this.AuthorUsername = q.Username; } } My main aim is to reduce repeating code

  Read the article

• SQL University: What and why of database refactoring

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Tools of the trade This is a second part of the series and in it we’ll take a look at what database refactoring is and why do it. Why refactor a database To know why refactor we first have to know what refactoring actually is. Code refactoring is a process where we change module internals in a way that does not change that module’s input/output behavior. For successful refactoring there is one crucial thing we absolutely must have: Tests. Automated unit tests are the only guarantee we have that we haven’t broken the input/output behavior before refactoring. If you haven’t go back ad read my post on the matter. Then start writing them. Next thing you need is a code module. Those are views, UDFs and stored procedures. By having direct table access we can kiss fast and sweet refactoring good bye. One more point to have a database abstraction layer. And no, ORM’s don’t fall into that category. But also know that refactoring is NOT adding new functionality to your code. Many have fallen into this trap. Don’t be one of them and resist the lure of the dark side. And it’s a strong lure. We developers in general love to add new stuff to our code, but hate fixing our own mistakes or changing existing code for no apparent reason. To be a good refactorer one needs discipline and focus. Now we know that refactoring is all about changing inner workings of existing code. This can be due to performance optimizations, changing internal code workflows or some other reason. This is a typical black box scenario to the outside world. If we upgrade the car engine it still has to drive on the road (preferably faster) and not fly (no matter how cool that would be). Also be aware that white box tests will break when we refactor. What to refactor in a database Refactoring databases doesn’t happen that often but when it does it can include a lot of stuff. Let us look at a few common cases. Adding or removing database schema objects Adding, removing or changing table columns in any way, adding constraints, keys, etc… All of these can be counted as internal changes not visible to the data consumer. But each of these carries a potential input/output behavior change. Dropping a column can result in views not working anymore or stored procedure logic crashing. Adding a unique constraint shows duplicated data that shouldn’t exist. Foreign keys break a truncate table command executed from an application that runs once a month. All these scenarios are very real and can happen. With the proper database abstraction layer fully covered with black box tests we can make sure something like that does not happen (hopefully at all). Changing physical structures Physical structures include heaps, indexes and partitions. We can pretty much add or remove those without changing the data returned by the database. But the performance can be affected. So here we use our performance tests. We do have them, right? Just by adding a single index we can achieve orders of magnitude performance improvement. Won’t that make users happy? But what if that index causes our write operations to crawl to a stop. again we have to test this. There are a lot of things to think about and have tests for. Without tests we can’t do successful refactoring! Fixing bad code We all have some bad code in our systems. We usually refer to that code as code smell as they violate good coding practices. Examples of such code smells are SQL injection, use of SELECT *, scalar UDFs or cursors, etc… Each of those is huge code smell and can result in major code changes. Take SELECT * from example. If we remove a column from a table the client using that SELECT * statement won’t have a clue about that until it runs. Then it will gracefully crash and burn. Not to mention the widely unknown SELECT * view refresh problem that Tomas LaRock (@SQLRockstar on Twitter) and Colin Stasiuk (@BenchmarkIT on Twitter) talk about in detail. Go read about it, it’s informative. Refactoring this includes replacing the * with column names and most likely change to application using the database. Breaking apart huge stored procedures Have you ever seen seen a stored procedure that was 2000 lines long? I have. It’s not pretty. It hurts the eyes and sucks the will to live the next 10 minutes. They are a maintenance nightmare and turn into things no one dares to touch. I’m willing to bet that 100% of time they don’t have a single test on them. Large stored procedures (and functions) are a clear sign that they contain business logic. General opinion on good database coding practices says that business logic has no business in the database. That’s the applications part. Refactoring such behemoths requires writing lots of edge case tests for the stored procedure input/output behavior and then start to refactor it. First we split the logic inside into smaller parts like new stored procedures and UDFs. Those then get called from the master stored procedure. Once we’ve successfully modularized the database code it’s best to transfer that logic into the applications consuming it. This only leaves the stored procedure with common data manipulation logic. Of course this isn’t always possible so having a plethora of performance and behavior unit tests is absolutely necessary to confirm we’ve actually improved the codebase in some way.   Refactoring is not a popular chore amongst developers or managers. The former don’t like fixing old code, the latter can’t see the financial benefit. Remember how we talked about being lousy at estimating future costs in the previous post? But there comes a time when it must be done. Hopefully I’ve given you some ideas how to get started. In the last post of the series we’ll take a look at the tools to use and an example of testing and refactoring.

  Read the article

• How do you separate the template of a blog block in Drupal?

  - by Ralph

  Hi, In Drupal, I created a block using views. This block contains the latest blog entries. I've placed this on a specific page to display it as an archive. Now, as for the blog itself (for example when one of them is clicked), A blog template for it depends on node-blog.tpl.php. My problem is, when I style node-blog.tpl.php, the block I created for the archives (as it displays on the page) gets affected. For example if I add TEST on node-blog.tpl.php, I will also get that on the block for every entry. I think it's because it is associated to a blog entry? What I want is to have node-blog styled "alone" when blog entries are viewed individually and not get the other entries on the blocks on the archive page be affected. How should I do this?

  Read the article

• FileNameColumnName property, Flat File Source Adapter : SSIS Nugget

  - by jamiet

  I saw a question on MSDN’s SSIS forum the other day that went something like this: I’m loading data into a table from a flat file but I want to be able to store the name of that file as well. Is there a way of doing that? I don’t want to come across as disrespecting those who took the time to reply but there was a few answers along the lines of “loop over the files using a For Each, store the file name in a variable yadda yadda yadda” when in fact there is a much much simpler way of accomplishing this; it just happens to be a little hidden away as I shall now explain! The Flat File Source Adapter has a property called FileNameColumnName which for some reason it isn’t exposed through the Flat File Source editor, it is however exposed via the Advanced Properties: You’ll see in the screenshot above that I have set FileNameColumnName=“Filename” (it doesn’t matter what name you use, anything except a non-zero string will work). What this will do is create a new column in our dataflow called “Filename” that contains, unsurprisingly, the name of the file from which the row was sourced. All very simple. This is particularly useful if you are extracting data from multiple files using the MultiFlatFile Connection Manager as it allows you to differentiate between data from each of the files as you can see in the following screenshot: So there you have it, the FileNameColumnName property; a little known secret of SSIS. I hope it proves to be useful to someone out there. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• Dynamic Unpivot : SSIS Nugget

  - by jamiet

  A question on the SSIS forum earlier today asked: I need to dynamically unpivot some set of columns in my source file. Every month there is one new column and its set of Values. I want to unpivot it without editing my SSIS packages that is deployed Let’s be clear about what we mean by Unpivot. It is a normalisation technique that basically converts columns into rows. By way of example it converts something like this: AccountCode Jan Feb Mar AC1 100.00 150.00 125.00 AC2 45.00 75.50 90.00 into something like this: AccountCode Month Amount AC1 Jan 100.00 AC1 Feb 150.00 AC1 Mar 125.00 AC2 Jan 45.00 AC2 Feb 75.50 AC2 Mar 90.00 The Unpivot transformation in SSIS is perfectly capable of carrying out the operation defined in this example however in the case outlined in the aforementioned forum thread the problem was a little bit different. I interpreted it to mean that the number of columns could change and in that scenario the Unpivot transformation (and indeed the SSIS dataflow in general) is rendered useless because it expects that the number of columns will not change from what is specified at design-time. There is a workaround however. Assuming all of the columns that CAN exist will appear at the end of the rows, we can (1) import all of the columns in the file as just a single column, (2) use a script component to loop over all the values in that “column” and (3) output each one as a column all of its own. Let’s go over that in a bit more detail.   I’ve prepared a data file that shows some data that we want to unpivot which shows some customers and their mythical shopping lists (it has column names in the first row): We use a Flat File Connection Manager to specify the format of our data file to SSIS: and a Flat File Source Adapter to put it into the dataflow (no need a for a screenshot of that one – its very basic). Notice that the values that we want to unpivot all exist in a column called [Groceries]. Now onto the script component where the real work goes on, although the code is pretty simple: Here I show a screenshot of this executing along with some data viewers. As you can see we have successfully pulled out all of the values into a row all of their own thus accomplishing the Dynamic Unpivot that the forum poster was after. If you want to run the demo for yourself then I have uploaded the demo package and source file up to my SkyDrive: http://cid-550f681dad532637.skydrive.live.com/self.aspx/Public/BlogShare/20100529/Dynamic%20Unpivot.zip Simply extract the two files into a folder, make sure the Connection Manager is pointing to the file, and execute! Hope this is useful. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• It’s nice to be important, but it’s more important to be nice

  - by BuckWoody

  I’ve been a little “preachy” lately, telling you that you should let people finish their sentences, and always check a problem out before you tell a user that their issue is “impossible”. Well, I’ll round that out with one more tip today. Keep in mind that all of these things are actions I’ve been guilty of, hopefully in the past. I’m kind of a “work in progress”. And yes, I know these tips are coming from someone who picks on people in presentations, but that is of course done in fun, and (hopefully) with the audience’s knowledge.   (No, this isn’t aimed at any one person or event in particular – I just see it happen a lot)   I’ve seen, unfortunately over and over, someone in authority react badly to someone who is incorrect, or at least perceived to be incorrect. This might manifest itself in a comment, post, question or whatever, but the point is that I’ve seen really intelligent people literally attack someone they view as getting something wrong. Don’t misunderstand me; if someone posts that you should always drop a production database in the middle of the day I think you should certainly speak up and mention that this might be a bad idea!  No, I’m talking about generalizations or even incorrect statements done in good faith. Let me explain with an example.   Suppose someone makes the statement: “If you don’t have enough space on your system, you can just use a DBCC command to shrink the database”. Let’s take two responses to this statement.   Response One: “That’s insane. Everyone knows that shrinking a database is a stupid idea, you’re just going to fragment your indexes all over the place.” Response Two: “That’s an interesting take – in my experience and from what I’ve read here (someurl.com) I think this might not be a universal best practice.”   Of course, both responses let the person making the statement and those reading it know that you don’t agree, and that it’s probably wrong. But the person you responded to and the general audience hearing you (or reading your response) might form two different opinions of you.   The first response says to me “this person really needs to be right, and takes arguments personally. They aren’t thinking of the other person at all, or the folks reading or hearing the exchange. They turned an incorrect technical statement into a personal attack. They haven’t left the other party any room to ‘save face’, and they have potentially turned what could be a positive learning experience for everyone into a negative. Also, they sound more than just a little arrogant.”   The second response says to me “this person has left room for everyone to save face, has presented evidence to the contrary and is thinking about moving the ball forward and getting it right rather than attacking someone for getting it wrong.” It’s the idea of questioning a statement rather than attacking a person.   Perhaps you have a different take. Maybe you think the “direct” approach is best – and maybe that’s worked for you. Something to consider is what you’ve really accomplished while using that first method. Sure, the info you provide is correct, and perhaps someone out there won’t shrink a database because of your response – but perhaps you’ve turned a lot more people off, and now they won’t listen to your other valuable information. You’ll be an expert, but another one of the nameless, arrogant jerks in technology. And I don’t think anyone likes to be thought of that way.   OK, I’ll get down off of the high-horse now. And I’ll keep the title of this entry (said to me by my grandmother when I was a little kid) in mind when I dismount. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• It’s nice to be important, but it’s more important to be nice

  - by BuckWoody

  I’ve been a little “preachy” lately, telling you that you should let people finish their sentences, and always check a problem out before you tell a user that their issue is “impossible”. Well, I’ll round that out with one more tip today. Keep in mind that all of these things are actions I’ve been guilty of, hopefully in the past. I’m kind of a “work in progress”. And yes, I know these tips are coming from someone who picks on people in presentations, but that is of course done in fun, and (hopefully) with the audience’s knowledge.   (No, this isn’t aimed at any one person or event in particular – I just see it happen a lot)   I’ve seen, unfortunately over and over, someone in authority react badly to someone who is incorrect, or at least perceived to be incorrect. This might manifest itself in a comment, post, question or whatever, but the point is that I’ve seen really intelligent people literally attack someone they view as getting something wrong. Don’t misunderstand me; if someone posts that you should always drop a production database in the middle of the day I think you should certainly speak up and mention that this might be a bad idea!  No, I’m talking about generalizations or even incorrect statements done in good faith. Let me explain with an example.   Suppose someone makes the statement: “If you don’t have enough space on your system, you can just use a DBCC command to shrink the database”. Let’s take two responses to this statement.   Response One: “That’s insane. Everyone knows that shrinking a database is a stupid idea, you’re just going to fragment your indexes all over the place.” Response Two: “That’s an interesting take – in my experience and from what I’ve read here (someurl.com) I think this might not be a universal best practice.”   Of course, both responses let the person making the statement and those reading it know that you don’t agree, and that it’s probably wrong. But the person you responded to and the general audience hearing you (or reading your response) might form two different opinions of you.   The first response says to me “this person really needs to be right, and takes arguments personally. They aren’t thinking of the other person at all, or the folks reading or hearing the exchange. They turned an incorrect technical statement into a personal attack. They haven’t left the other party any room to ‘save face’, and they have potentially turned what could be a positive learning experience for everyone into a negative. Also, they sound more than just a little arrogant.”   The second response says to me “this person has left room for everyone to save face, has presented evidence to the contrary and is thinking about moving the ball forward and getting it right rather than attacking someone for getting it wrong.” It’s the idea of questioning a statement rather than attacking a person.   Perhaps you have a different take. Maybe you think the “direct” approach is best – and maybe that’s worked for you. Something to consider is what you’ve really accomplished while using that first method. Sure, the info you provide is correct, and perhaps someone out there won’t shrink a database because of your response – but perhaps you’ve turned a lot more people off, and now they won’t listen to your other valuable information. You’ll be an expert, but another one of the nameless, arrogant jerks in technology. And I don’t think anyone likes to be thought of that way.   OK, I’ll get down off of the high-horse now. And I’ll keep the title of this entry (said to me by my grandmother when I was a little kid) in mind when I dismount. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• How I use schemas.

  - by Alexander Kuznetsov

  I use schemas to simplify granting permissions. For tables and views, I have three schemas: Data, the actual data my customers need. Can only be modified via sprocs. Staging, only visible to data loaders and devs. Full privileges on INSERT?UPDATE/DELETE for those who see it. Config, the configuration data used in loads, only visible to data loaders and devs. Can only be modified via sprocs. For sprocs/UDFs I have the following schemas: Readers Writers ETL ConfigReaders ConfigWriters Also I have dbo...(read more)

  Read the article

• FileNameColumnName property, Flat File Source Adapter : SSIS Nugget

  - by jamiet

  I saw a question on MSDN’s SSIS forum the other day that went something like this: I’m loading data into a table from a flat file but I want to be able to store the name of that file as well. Is there a way of doing that? I don’t want to come across as disrespecting those who took the time to reply but there was a few answers along the lines of “loop over the files using a For Each, store the file name in a variable yadda yadda yadda” when in fact there is a much much simpler way of accomplishing this; it just happens to be a little hidden away as I shall now explain! The Flat File Source Adapter has a property called FileNameColumnName which for some reason it isn’t exposed through the Flat File Source editor, it is however exposed via the Advanced Properties: You’ll see in the screenshot above that I have set FileNameColumnName=“Filename” (it doesn’t matter what name you use, anything except a non-zero string will work). What this will do is create a new column in our dataflow called “Filename” that contains, unsurprisingly, the name of the file from which the row was sourced. All very simple. This is particularly useful if you are extracting data from multiple files using the MultiFlatFile Connection Manager as it allows you to differentiate between data from each of the files as you can see in the following screenshot: So there you have it, the FileNameColumnName property; a little known secret of SSIS. I hope it proves to be useful to someone out there. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• Windows and SQL Azure Best Practices: Affinity Groups

  - by BuckWoody

  When you create a Windows Azure application, you’ll pick a subscription to put it under. This is a billing container - underneath that, you’ll deploy a Hosted Service. That holds the Web and Worker Roles that you’ll deploy for your applications. along side that, you use the Storage Account to create storage for the application. (In some cases, you might choose to use only storage or Roles - the info here applies anyway) As you are setting up your environment, you’re asked to pick a “region” where your application will run. If you choose a Region, you’ll be asked where to put the Roles. You’re given choices like Asia, North America and so on. This is where the hardware that physically runs your code lives. We have lots of fault domains, power considerations and so on to keep that set of datacenters running, but keep in mind that this is where the application lives. You also get this selection for Storage Accounts. When you make new storage, it’s a best practice to put it where your computing is. This makes the shortest path from the code to the data, and then back out to the user. One of the selections for the location is “Anywhere U.S.”. This selection might be interpreted to mean that we will bias towards keeping the data and the code together, but that may not be the case. There is a specific abstraction we created for just that purpose: Affinity Groups. An Affinity Group is simply a name you can use to tie together resources. You can do this in two places - when you’re creating the Hosted Service (shown above) and on it’s own tree item on the left, called “Affinity Groups”. When you select either of those actions, You’re presented with a dialog box that allows you to specify a name, and then the Region that  names ties the resources to. Now you can select that Affinity Group just as if it were a Region, and your code and data will stay together. That helps with keeping the performance high. Official Documentation: http://msdn.microsoft.com/en-us/library/windowsazure/hh531560.aspx

  Read the article

• Getting It Right The First Time

  - by andyleonard

  Introduction This post is the seventeenth part of a ramble-rant about the software business. The current posts in this series are: Goodwill, Negative and Positive Visions, Quests, Missions Right, Wrong, and Style Follow Me Balance, Part 1 Balance, Part 2 Definition of a Great Team The 15-Minute Meeting Metaproblems: Drama The Right Question Software is Organic, Part 1 Metaproblem: Terror I Don't Work On My Car A Turning Point Human Doings Everything Changes This post is about getting software right...(read more)

  Read the article

• Speaking at PASS 2012… Exciting and Scary… As usual…

  - by drsql

  Edit: As I reread this, I felt I should clarify.. As usual refers mostly to the "Scary" part. I have a lot of stage fright that I have to work through. And it is always exciting to be picked. I have been selected this year at the PASS Summit 2012 to do two sessions, and they are both going to be interesting. Pre-Con: Relational Database Design Workshop - Abstract Triggers: Born Evil or Misunderstood? - Abstract The pre-con session entitled Relational Database Design Workshop will be (at least) the...(read more)

  Read the article

• Book Review: Pro SQL Server 2008 Relational Database Design and Implementation

  - by Alexander Kuznetsov

  Investing in proper database design is a very efficient way to cut maintenance costs. If we expect a system to last, we need to make sure it has a good solid foundation - high quality database design. Surely we can and sometimes do cut corners and save on database design to get things done faster. Unfortunately, such cutting corners frequently comes back and bites us: we may end up spending a lot of time solving issues caused by poor design. So, solid understanding of relational database design is...(read more)

  Read the article

• Uploading and Importing CSV file to SQL Server in ASP.NET WebForms

  - by Vincent Maverick Durano

  Few weeks ago I was working with a small internal project  that involves importing CSV file to Sql Server database and thought I'd share the simple implementation that I did on the project. In this post I will demonstrate how to upload and import CSV file to SQL Server database. As some may have already know, importing CSV file to SQL Server is easy and simple but difficulties arise when the CSV file contains, many columns with different data types. Basically, the provider cannot differentiate data types between the columns or the rows, blindly it will consider them as a data type based on first few rows and leave all the data which does not match the data type. To overcome this problem, I used schema.ini file to define the data type of the CSV file and allow the provider to read that and recognize the exact data types of each column. Now what is schema.ini? Taken from the documentation: The Schema.ini is a information file, used to define the data structure and format of each column that contains data in the CSV file. If schema.ini file exists in the directory, Microsoft.Jet.OLEDB provider automatically reads it and recognizes the data type information of each column in the CSV file. Thus, the provider intelligently avoids the misinterpretation of data types before inserting the data into the database. For more information see: http://msdn.microsoft.com/en-us/library/ms709353%28VS.85%29.aspx Points to remember before creating schema.ini:   1. The schema information file, must always named as 'schema.ini'.   2. The schema.ini file must be kept in the same directory where the CSV file exists.   3. The schema.ini file must be created before reading the CSV file.   4. The first line of the schema.ini, must the name of the CSV file, followed by the properties of the CSV file, and then the properties of the each column in the CSV file. Here's an example of how the schema looked like: [Employee.csv] ColNameHeader=False Format=CSVDelimited DateTimeFormat=dd-MMM-yyyy Col1=EmployeeID Long Col2=EmployeeFirstName Text Width 100 Col3=EmployeeLastName Text Width 50 Col4=EmployeeEmailAddress Text Width 50 To get started lets's go a head and create a simple blank database. Just for the purpose of this demo I created a database called TestDB. After creating the database then lets go a head and fire up Visual Studio and then create a new WebApplication project. Under the root application create a folder called UploadedCSVFiles and then place the schema.ini on that folder. The uploaded CSV files will be stored in this folder after the user imports the file. Now add a WebForm in the project and set up the HTML mark up and add one (1) FileUpload control one(1)Button and three (3) Label controls. After that we can now proceed with the codes for uploading and importing the CSV file to SQL Server database. Here are the full code blocks below: 1: using System; 2: using System.Data; 3: using System.Data.SqlClient; 4: using System.Data.OleDb; 5: using System.IO; 6: using System.Text; 7:   8: namespace WebApplication1 9: { 10: public partial class CSVToSQLImporting : System.Web.UI.Page 11: { 12: private string GetConnectionString() 13: { 14: return System.Configuration.ConfigurationManager.ConnectionStrings["DBConnectionString"].ConnectionString; 15: } 16: private void CreateDatabaseTable(DataTable dt, string tableName) 17: { 18:   19: string sqlQuery = string.Empty; 20: string sqlDBType = string.Empty; 21: string dataType = string.Empty; 22: int maxLength = 0; 23: StringBuilder sb = new StringBuilder(); 24:   25: sb.AppendFormat(string.Format("CREATE TABLE {0} (", tableName)); 26:   27: for (int i = 0; i < dt.Columns.Count; i++) 28: { 29: dataType = dt.Columns[i].DataType.ToString(); 30: if (dataType == "System.Int32") 31: { 32: sqlDBType = "INT"; 33: } 34: else if (dataType == "System.String") 35: { 36: sqlDBType = "NVARCHAR"; 37: maxLength = dt.Columns[i].MaxLength; 38: } 39:   40: if (maxLength > 0) 41: { 42: sb.AppendFormat(string.Format(" {0} {1} ({2}), ", dt.Columns[i].ColumnName, sqlDBType, maxLength)); 43: } 44: else 45: { 46: sb.AppendFormat(string.Format(" {0} {1}, ", dt.Columns[i].ColumnName, sqlDBType)); 47: } 48: } 49:   50: sqlQuery = sb.ToString(); 51: sqlQuery = sqlQuery.Trim().TrimEnd(','); 52: sqlQuery = sqlQuery + " )"; 53:   54: using (SqlConnection sqlConn = new SqlConnection(GetConnectionString())) 55: { 56: sqlConn.Open(); 57: SqlCommand sqlCmd = new SqlCommand(sqlQuery, sqlConn); 58: sqlCmd.ExecuteNonQuery(); 59: sqlConn.Close(); 60: } 61:   62: } 63: private void LoadDataToDatabase(string tableName, string fileFullPath, string delimeter) 64: { 65: string sqlQuery = string.Empty; 66: StringBuilder sb = new StringBuilder(); 67:   68: sb.AppendFormat(string.Format("BULK INSERT {0} ", tableName)); 69: sb.AppendFormat(string.Format(" FROM '{0}'", fileFullPath)); 70: sb.AppendFormat(string.Format(" WITH ( FIELDTERMINATOR = '{0}' , ROWTERMINATOR = '\n' )", delimeter)); 71:   72: sqlQuery = sb.ToString(); 73:   74: using (SqlConnection sqlConn = new SqlConnection(GetConnectionString())) 75: { 76: sqlConn.Open(); 77: SqlCommand sqlCmd = new SqlCommand(sqlQuery, sqlConn); 78: sqlCmd.ExecuteNonQuery(); 79: sqlConn.Close(); 80: } 81: } 82: protected void Page_Load(object sender, EventArgs e) 83: { 84:   85: } 86: protected void BTNImport_Click(object sender, EventArgs e) 87: { 88: if (FileUpload1.HasFile) 89: { 90: FileInfo fileInfo = new FileInfo(FileUpload1.PostedFile.FileName); 91: if (fileInfo.Name.Contains(".csv")) 92: { 93:   94: string fileName = fileInfo.Name.Replace(".csv", "").ToString(); 95: string csvFilePath = Server.MapPath("UploadedCSVFiles") + "\\" + fileInfo.Name; 96:   97: //Save the CSV file in the Server inside 'MyCSVFolder' 98: FileUpload1.SaveAs(csvFilePath); 99:   100: //Fetch the location of CSV file 101: string filePath = Server.MapPath("UploadedCSVFiles") + "\\"; 102: string strSql = "SELECT * FROM [" + fileInfo.Name + "]"; 103: string strCSVConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";" + "Extended Properties='text;HDR=YES;'"; 104:   105: // load the data from CSV to DataTable 106:   107: OleDbDataAdapter adapter = new OleDbDataAdapter(strSql, strCSVConnString); 108: DataTable dtCSV = new DataTable(); 109: DataTable dtSchema = new DataTable(); 110:   111: adapter.FillSchema(dtCSV, SchemaType.Mapped); 112: adapter.Fill(dtCSV); 113:   114: if (dtCSV.Rows.Count > 0) 115: { 116: CreateDatabaseTable(dtCSV, fileName); 117: Label2.Text = string.Format("The table ({0}) has been successfully created to the database.", fileName); 118:   119: string fileFullPath = filePath + fileInfo.Name; 120: LoadDataToDatabase(fileName, fileFullPath, ","); 121:   122: Label1.Text = string.Format("({0}) records has been loaded to the table {1}.", dtCSV.Rows.Count, fileName); 123: } 124: else 125: { 126: LBLError.Text = "File is empty."; 127: } 128: } 129: else 130: { 131: LBLError.Text = "Unable to recognize file."; 132: } 133:   134: } 135: } 136: } 137: } The code above consists of three (3) private methods which are the GetConnectionString(), CreateDatabaseTable() and LoadDataToDatabase(). The GetConnectionString() is a method that returns a string. This method basically gets the connection string that is configured in the web.config file. The CreateDatabaseTable() is method that accepts two (2) parameters which are the DataTable and the filename. As the method name already suggested, this method automatically create a Table to the database based on the source DataTable and the filename of the CSV file. The LoadDataToDatabase() is a method that accepts three (3) parameters which are the tableName, fileFullPath and delimeter value. This method is where the actual saving or importing of data from CSV to SQL server happend. The codes at BTNImport_Click event handles the uploading of CSV file to the specified location and at the same time this is where the CreateDatabaseTable() and LoadDataToDatabase() are being called. If you notice I also added some basic trappings and validations within that event. Now to test the importing utility then let's create a simple data in a CSV format. Just for the simplicity of this demo let's create a CSV file and name it as "Employee" and add some data on it. Here's an example below: 1,VMS,Durano,[email protected] 2,Jennifer,Cortes,[email protected] 3,Xhaiden,Durano,[email protected] 4,Angel,Santos,[email protected] 5,Kier,Binks,[email protected] 6,Erika,Bird,[email protected] 7,Vianne,Durano,[email protected] 8,Lilibeth,Tree,[email protected] 9,Bon,Bolger,[email protected] 10,Brian,Jones,[email protected] Now save the newly created CSV file in some location in your hard drive. Okay let's run the application and browse the CSV file that we have just created. Take a look at the sample screen shots below: After browsing the CSV file. After clicking the Import Button Now if we look at the database that we have created earlier you'll notice that the Employee table is created with the imported data on it. See below screen shot.   That's it! I hope someone find this post useful! Technorati Tags: ASP.NET,CSV,SQL,C#,ADO.NET

  Read the article

• I want to hit Apex SQL with a big stick

  - by Michael Stephenson

  <Whinge> Thought id just have a little whinge about this product which caused me a load of grief the other day..... So the background was that my development machine had a completely full hard disk which I needed to sort out.  Upon investigation I found the issue was that the msdb database had managed to get very large. This was caused because a long time ago (and I cant even remember why) I tried out Apex SQL.  After a few days I decided to uninstall it and thought nothing more of it.  What I didnt realise was that uninstalling it doesnt actually uninstall it (and it doesnt inform you about this), but there was still some assemblies left on my machine.  Everytime SQL Server was running it was starting the Apex SQL Connection monitor which was then running in the background and regularly recording information in the msdb database.  Over time it had recorded enough to fill the disk. The below article advises how to sort this out by removing this fully so if your having a problem then try this out:http://knowledgebase.apexsql.com/2007/08/how-to-uninstall-apexsqlconnectionmonit_09.htm Once this was sorted out its interesting to read the above article because I just dont think the approach used by the vendor of this software is a very good one.  So for the Apex team just wanted to pass on a thought: If I want to uninstall your product you should tell me if stuff is left on the machine especially if a process will be running which is going to fill my machine with useless data, </Whinge>

  Read the article

• Geek City: SQL Server 2014 In-Memory OLTP (“Hekaton”) Whitepaper for CTP2

  - by Kalen Delaney

  Last week at the PASS Summit in Charlotte, NC, the update of my whitepaper for CTP2 was released. The manager supervising the paper at Microsoft told me that David DeWitt himself said some very nice things about the technical quality of the paper, which was one of the most ego enhancing compliments I have ever gotten! Unfortunately, Dr. DeWitt said those things at his “After-the-keynote” session, not in the keynote that was recorded, so I only have my manager’s word for it. But I’ll take what I can...(read more)

  Read the article

• Visualising data a different way with Pivot collections

  - by Rob Farley

  Roger’s been doing a great job extending PivotViewer recently, and you can find the list of LobsterPot pivots at http://pivot.lobsterpot.com.au Many months back, the TED Talk that Gary Flake did about Pivot caught my imagination, and I did some research into it. At the time, most of what we did with Pivot was geared towards what we could do for clients, including making Pivot collections based on students at a school, and using it to browse PDF invoices by their various properties. We had actual commercial work based on Pivot collections back then, and it was all kinds of fun. Later, we made some collections for events that were happening, and even got featured in the TechEd Australia keynote. But I’m getting ahead of myself... let me explain the concept. A Pivot collection is an XML file (with .cxml extension) which lists Items, each linking to an image that’s stored in a Deep Zoom format (this means that it contains tiles like Bing Maps, so that the browser can request only the ones of interest according to the zoom level). This collection can be shown in a Silverlight application that uses the PivotViewer control, or in the Pivot Browser that’s available from getpivot.com. Filtering and sorting the items according to their facets (attributes, such as size, age, category, etc), the PivotViewer rearranges the way that these are shown in a very dynamic way. To quote Gary Flake, this lets us “see patterns which are otherwise hidden”. This browsing mechanism is very suited to a number of different methods, because it’s just that – browsing. It’s not searching, it’s more akin to window-shopping than doing an internet search. When we decided to put something together for the conferences such as TechEd Australia 2010 and the PASS Summit 2010, we did some screen-scraping to provide a different view of data that was already available online. Nick Hodge and Michael Kordahi from Microsoft liked the idea a lot, and after a bit of tweaking, we produced one that Michael used in the TechEd Australia keynote to show the variety of talks on offer. It’s interesting to see a pattern in this data: The Office track has the most sessions, but if the Interactive Sessions and Instructor-Led Labs are removed, it drops down to only the sixth most popular track, with Cloud Computing taking over. This is something which just isn’t obvious when you look an ordinary search tool. You get a much better feel for the data when moving around it like this. The more observant amongst you will have noticed some difference in the collection that Michael is demonstrating in the picture above with the screenshots I’ve shown. That’s because it’s been extended some more. At the SQLBits conference in the UK this year, I had some interesting discussions with the guys from Xpert360, particularly Phil Carter, who I’d met in 2009 at an earlier SQLBits conference. They had got around to producing a Pivot collection based on the SQLBits data, which we had been planning to do but ran out of time. We discussed some of ways that Pivot could be used, including the ways that my old friend Howard Dierking had extended it for the MSDN Magazine. I’m not suggesting I influenced Xpert360 at all, but they certainly inspired us with some of their posts on the matter So with LobsterPot guys David Gardiner and Roger Noble both having dabbled in Pivot collections (and Dave doing some for clients), I set Roger to work on extending it some more. He’s used various events and so on to be able to make an environment that allows us to do quick deployment of new collections, as well as showing the data in a grid view which behaves as if it were simply a third view of the data (the other two being the array of images and the ‘histogram’ view). I see PivotViewer as being a significant step in data visualisation – so much so that I feature it when I deliver talks on Spatial Data Visualisation methods. Any time when there is information that can be conveyed through an image, you have to ask yourself how best to show that image, and whether that image is the focal point. For Spatial data, the image is most often a map, and the map becomes the central mode for navigation. I show Pivot with postcode areas, since I can browse the postcodes based on their data, and many of the images are recognisable (to locals of South Australia). Naturally, the images could link through to the map itself, and so on, but generally people think of Spatial data in terms of navigating a map, which doesn’t always gel with the information you’re trying to extract. Roger’s even looking into ways to hook PivotViewer into the Bing Maps API, in a similar way to the Deep Earth project, displaying different levels of map detail according to how ‘zoomed in’ the images are. Some of the work that Dave did with one of the schools was generating the Deep Zoom tiles “on the fly”, based on images stored in a database, and Roger has produced a collection which uses images from flickr, that lets you move from one search term to another. Pulling the images down from flickr.com isn’t particularly ideal from a performance aspect, and flickr doesn’t store images in a small-enough format to really lend itself to this use, but you might agree that it’s an interesting concept which compares nicely to using Maps. I’m looking forward to future versions of the PivotViewer control, and hope they provide many more events that can be used, and even more hooks into it. Naturally, LobsterPot could help provide your business with a PivotViewer experience, but you can probably do a lot of it yourself too. There’s a thorough guide at getpivot.com, which is how we got into it. For some examples of what we’ve done, have a look at http://pivot.lobsterpot.com.au. I’d like to see PivotViewer really catch on a data visualisation tool.

  Read the article

• After restoring a SQL Server database from another server - get login fails

  - by Renso

  Issue: After you have restored a sql server database from another server, lets say from production to a Q/A environment, you get the "Login Fails" message for your service account. Reason: User logon information is stored in the syslogins table in the master database. By changing servers, or by altering this information by rebuilding or restoring an old version of the master database, the information may be different from when the user database dump was created. If logons do not exist for the users, they will receive an error indicating "Login failed" while attempting to log on to the server. If the user logons do exist, but the SUID values (for 6.x) or SID values (for 7.0) in master..syslogins and the sysusers table in the user database differ, the users may have different permissions than expected in the user database. Solution: Links a user entry in the sys.database_principals system catalog view in the current database to a SQL Server login of the same name. If a login with the same name does not exist, one will be created. Examine the result from the Auto_Fix statement to confirm that the correct link is in fact made. Avoid using Auto_Fix in security-sensitive situations. When you use Auto_Fix, you must specify user and password if the login does not already exist, otherwise you must specify user but password will be ignored. login must be NULL. user must be a valid user in the current database. The login cannot have another user mapped to it. execute the following stored procedure, in this example the login user name is "MyUser" exec sp_change_users_login 'Auto_Fix', 'MyUser'   NOTE: sp_change_users_login cannot be used with a SQL Server login created from a Windows principal or with a user created by using CREATE USER WITHOUT LOGIN.

  Read the article

• Do you need all that data?

  - by BuckWoody

  I read an amazing post over on ars technica (link: http://arstechnica.com/science/news/2010/03/the-software-brains-behind-the-particle-colliders.ars?utm_source=rss&utm_medium=rss&utm_campaign=rss) abvout the LHC, or as they are also known, the "particle colliders". Beyond just the pure scientific geek awesomeness, these instruments have the potential to collect more data than you can (or possibly should) store. Actually, this problem has a lot in common with a BI system. There's so much granular detail available in the source systems that a designer has to decide how, and how much, to roll up the data. Whenver you do that, you lose fidelity, but in many cases that's OK. Take, for example, your car's speedometer. You don't actually need to track each and every point of speed as it happens. You only need to know that you're hovering around the speed limit at a certain point in time. Since this is the way that humans percieve data, is there some lesson we should take in the design of data "flows" - and what implications does this have for new technologies like StreamInsight? Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

  Read the article

• Commit in SQL

  - by PRajkumar

  SQL Transaction Control Language Commands (TCL)                                           (COMMIT) Commit Transaction As a SQL language we use transaction control language very frequently. Committing a transaction means making permanent the changes performed by the SQL statements within the transaction. A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. This statement also erases all save points in the transaction and releases transaction locks. Oracle Database issues an implicit COMMIT before and after any data definition language (DDL) statement. Oracle recommends that you explicitly end every transaction in your application programs with a COMMIT or ROLLBACK statement, including the last transaction, before disconnecting from Oracle Database. If you do not explicitly commit the transaction and the program terminates abnormally, then the last uncommitted transaction is automatically rolled back.   Until you commit a transaction: ·         You can see any changes you have made during the transaction by querying the modified tables, but other users cannot see the changes. After you commit the transaction, the changes are visible to other users' statements that execute after the commit ·         You can roll back (undo) any changes made during the transaction with the ROLLBACK statement   Note: Most of the people think that when we type commit data or changes of what you have made has been written to data files, but this is wrong when you type commit it means that you are saying that your job has been completed and respective verification will be done by oracle engine that means it checks whether your transaction achieved consistency when it finds ok it sends a commit message to the user from log buffer but not from data buffer, so after writing data in log buffer it insists data buffer to write data in to data files, this is how it works.   Before a transaction that modifies data is committed, the following has occurred: ·         Oracle has generated undo information. The undo information contains the old data values changed by the SQL statements of the transaction ·         Oracle has generated redo log entries in the redo log buffer of the System Global Area (SGA). The redo log record contains the change to the data block and the change to the rollback block. These changes may go to disk before a transaction is committed ·         The changes have been made to the database buffers of the SGA. These changes may go to disk before a transaction is committed   Note:   The data changes for a committed transaction, stored in the database buffers of the SGA, are not necessarily written immediately to the data files by the database writer (DBWn) background process. This writing takes place when it is most efficient for the database to do so. It can happen before the transaction commits or, alternatively, it can happen some times after the transaction commits.   When a transaction is committed, the following occurs: 1.      The internal transaction table for the associated undo table space records that the transaction has committed, and the corresponding unique system change number (SCN) of the transaction is assigned and recorded in the table 2.      The log writer process (LGWR) writes redo log entries in the SGA's redo log buffers to the redo log file. It also writes the transaction's SCN to the redo log file. This atomic event constitutes the commit of the transaction 3.      Oracle releases locks held on rows and tables 4.      Oracle marks the transaction complete   Note:   The default behavior is for LGWR to write redo to the online redo log files synchronously and for transactions to wait for the redo to go to disk before returning a commit to the user. However, for lower transaction commit latency application developers can specify that redo be written asynchronously and that transaction do not need to wait for the redo to be on disk.   The syntax of Commit Statement is   COMMIT [WORK] [COMMENT ‘your comment’]; ·         WORK is optional. The WORK keyword is supported for compliance with standard SQL. The statements COMMIT and COMMIT WORK are equivalent. Examples Committing an Insert INSERT INTO table_name VALUES (val1, val2); COMMIT WORK; ·         COMMENT Comment is also optional. This clause is supported for backward compatibility. Oracle recommends that you used named transactions instead of commit comments. Specify a comment to be associated with the current transaction. The 'text' is a quoted literal of up to 255 bytes that Oracle Database stores in the data dictionary view DBA_2PC_PENDING along with the transaction ID if a distributed transaction becomes in doubt. This comment can help you diagnose the failure of a distributed transaction. Examples The following statement commits the current transaction and associates a comment with it: COMMIT     COMMENT 'In-doubt transaction Code 36, Call (415) 555-2637'; ·         WRITE Clause Use this clause to specify the priority with which the redo information generated by the commit operation is written to the redo log. This clause can improve performance by reducing latency, thus eliminating the wait for an I/O to the redo log. Use this clause to improve response time in environments with stringent response time requirements where the following conditions apply: The volume of update transactions is large, requiring that the redo log be written to disk frequently. The application can tolerate the loss of an asynchronously committed transaction. The latency contributed by waiting for the redo log write to occur contributes significantly to overall response time. You can specify the WAIT | NOWAIT and IMMEDIATE | BATCH clauses in any order. Examples To commit the same insert operation and instruct the database to buffer the change to the redo log, without initiating disk I/O, use the following COMMIT statement: COMMIT WRITE BATCH; Note: If you omit this clause, then the behavior of the commit operation is controlled by the COMMIT_WRITE initialization parameter, if it has been set. The default value of the parameter is the same as the default for this clause. Therefore, if the parameter has not been set and you omit this clause, then commit records are written to disk before control is returned to the user. WAIT | NOWAIT Use these clauses to specify when control returns to the user. The WAIT parameter ensures that the commit will return only after the corresponding redo is persistent in the online redo log. Whether in BATCH or IMMEDIATE mode, when the client receives a successful return from this COMMIT statement, the transaction has been committed to durable media. A crash occurring after a successful write to the log can prevent the success message from returning to the client. In this case the client cannot tell whether or not the transaction committed. The NOWAIT parameter causes the commit to return to the client whether or not the write to the redo log has completed. This behavior can increase transaction throughput. With the WAIT parameter, if the commit message is received, then you can be sure that no data has been lost. Caution: With NOWAIT, a crash occurring after the commit message is received, but before the redo log record(s) are written, can falsely indicate to a transaction that its changes are persistent. If you omit this clause, then the transaction commits with the WAIT behavior. IMMEDIATE | BATCH Use these clauses to specify when the redo is written to the log. The IMMEDIATE parameter causes the log writer process (LGWR) to write the transaction's redo information to the log. This operation option forces a disk I/O, so it can reduce transaction throughput. The BATCH parameter causes the redo to be buffered to the redo log, along with other concurrently executing transactions. When sufficient redo information is collected, a disk write of the redo log is initiated. This behavior is called "group commit", as redo for multiple transactions is written to the log in a single I/O operation. If you omit this clause, then the transaction commits with the IMMEDIATE behavior. ·         FORCE Clause Use this clause to manually commit an in-doubt distributed transaction or a corrupt transaction. ·         In a distributed database system, the FORCE string [, integer] clause lets you manually commit an in-doubt distributed transaction. The transaction is identified by the 'string' containing its local or global transaction ID. To find the IDs of such transactions, query the data dictionary view DBA_2PC_PENDING. You can use integer to specifically assign the transaction a system change number (SCN). If you omit integer, then the transaction is committed using the current SCN. ·         The FORCE CORRUPT_XID 'string' clause lets you manually commit a single corrupt transaction, where string is the ID of the corrupt transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to specify this clause. ·         Specify FORCE CORRUPT_XID_ALL to manually commit all corrupt transactions. You must have DBA privileges to specify this clause. Examples Forcing an in doubt transaction. Example The following statement manually commits a hypothetical in-doubt distributed transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to issue this statement. COMMIT FORCE '22.57.53';

  Read the article

• WCF Error when using “Match Data” function in MDS Excel AddIn

  - by Davide Mauri

  If you’re using MDS and DQS with the Excel Integration you may get an error when trying to use the “Match Data” feature that uses DQS in order to help to identify duplicate data in your data set. The error is quite obscure and you have to enable WCF error reporting in order to have the error details and you’ll discover that they are related to some missing permission in MDS and DQS_STAGING_DATA database. To fix the problem you just have to give the needed permession, as the following script does: use MDS go GRANT SELECT ON mdm.tblDataQualityOperationsState TO [VMSRV02\mdsweb] GRANT INSERT ON mdm.tblDataQualityOperationsState TO [VMSRV02\mdsweb] GRANT DELETE ON mdm.tblDataQualityOperationsState TO [VMSRV02\mdsweb] GRANT UPDATE ON mdm.tblDataQualityOperationsState TO [VMSRV02\mdsweb] USE [DQS_STAGING_DATA] GO ALTER AUTHORIZATION ON SCHEMA::[db_datareader] TO [VMSRV02\mdsweb] ALTER AUTHORIZATION ON SCHEMA::[db_datawriter] TO [VMSRV02\mdsweb] ALTER AUTHORIZATION ON SCHEMA::[db_ddladmin] TO [VMSRV02\mdsweb] GO Where “VMSRV02\mdsweb” is the user you configured for MDS Service execution. If you don’t remember it, you can just check which account has been assigned to the IIS application pool that your MDS website is using:

  Read the article

• July, the 31 Days of SQL Server DMO’s – Day 27 (sys.dm_db_file_space_usage)

  - by Tamarick Hill

  The sys.dm_db_file_space usage DMV returns information about database file space usage.  This DMV was enhanced for the 2012 version to include 3 additional columns. Let’s query this DMV against our AdventureWorks2012 database and view the results. SELECT * FROM sys.dm_db_file_space_usage The column returned from this DMV are really self-explanatory, but I will give you a description, paraphrased from books online, below. The first three columns returned from this DMV represent the Database, File, and Filegroup for the current database context that executed the DMV query. The next column is the total_page_count which represents the total number of pages in the file. The allocated_extent_page_count represents the total number of pages in all extents that have been allocated. The unallocated_extent_page_count represents the number of pages in the unallocated extents within the file. The version_store_reserved_page_count column represents the number of pages that are allocated to the version store. The user_object_reserved_page_count represents the number of pages allocated for user objects. The internal_object_reserved_page_count represents the number of pages allocated for internal objects.  Lastly is the mixed_extent_page_count which represents the total number of pages that are part of mixed extents. This is a great DMV for retrieving usage space information from your database files. For more information about this DMV, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms174412.aspx Follow me on Twitter @PrimeTimeDBA

  Read the article

< Previous Page | 395 396 397 398 399 400 401 402 403 404 405 406  | Next Page >