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Πρόσφατες Δημοσιεύσεις
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In this post I will be looking into a new feature in SQL Server 2012. Actually this is a T-SQL enhancement and it is called Query Paging.Often in our applications we need to page/select a number of rows (or a range of rows if you prefer) by specifying a row count offset in the results. I will be introducing OFFSET which specifies the number of rows to skip before starting and FETCH which specifies the number of rows after the OFFSET to return.We will use OFFSET/FETCH NEXT in combination with the ORDER BY clause. ( read more )...
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Before HTML5 when it came to creating rich interactive maps where one could hover or click any region and see details about them, Flash was the right tool for the job. Right now, though, it is much easier to create maps with JavaScript and, thanks to JS frameworks, it even gets much simpler and jVectorMap [...]...
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Following up on my post on how to fix CSpeex (http://cspeex.codeplex.com) to compile at Silverlight 5 (see http://zoomicon.wordpress.com/2012/06/09/fix-compile-cspeex-audio-codec-at-silverlight-4-rc-and-silverlight-5/). Initially I thought it was not working correctly, but then I noticed I was running it on Terminal Server and didn’t have an audio device available. Running SLAudioDemo included in the CSpeex distribution (after doing the fix [...]...
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In this post I will be looking into recompilation and stored procedures in SQL Server. More specifically I will show you why it happens,when it happens and the tools to identify recompilation of stored procedures.There are many reasons why a stored procedure will recompile. Some are more obvious than others.( read more )...
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According to http://www.w3.org/Style/Examples/007/center.en.html#vertical CSS level 2 doesn’t have a property for centering things vertically. There will probably be one in CSS level 3. But even in CSS2 you can center blocks vertically, by combining a few properties. The trick is to specify that the outer block is to be formatted as a table cell, because [...]...
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I was just examining a MonoX portal skin that our designer is authoring for the ClipFlair platform and noticed that in the Default.skin file, there’s a note pointing to http://support.microsoft.com/kb/911717 that speaks of an issue with Microsoft’s implementation of WebPartZone skins: There it says: The CssClass property does not affect the following style objects: •The [...]...
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Babylon Search is one of the most abusive addons for Mozilla Firefox and other web browsers. It installs with other free software (most probably profiting from tracking your searching habits) and then it is quite hard even for experienced users to completely uninstall it. While maintaining other computers in the past I’ve used a combination [...]...
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Πρωινή συζήτηση με συνάδελφο η οποία έφτασε να αξιολογούμε βάσεις και να μετράμε αντικείμενα σε αυτές. Κάποια στιγμή γράφω το παρακάτω query για να δω ανά object type τι πλήθος αντικειμένων έχω σε αυτό και ο συνάδελφος εντυπωσιάστηκε. Αν ποτέ το χρειαστείτε είναι το παρακάτω: περισσότερα...
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Some time ago I gave up on OneStop.net (after their support fell into zombie status and they managed to let my domain name expire) and eventually managed to arrange with the Network Solutions registrar that they were using under the hood to renew my expired domain name (there is some time before it is available [...]...
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For those of you that built Windows 8 applications one thing you’ll find out (probably the hard way as I did) is that you’ll need a Privacy Policy in order to publish your app to the Windows 8 app store. So if you don’t currently have those legal documents Termsfeed will come very handy as [...]...
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If you’re into metro development (windows phone or Windows 8) I’m sure you’ll appreciate another set of cool mono-colored very simplistic yet beautiful icons. iconmonstr offers a set which includes over 600 items with multiple variations for almost each element. Icons are mostly focused for web apps as most of them are actions, charts, badges [...]...
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Μια πρωινή ερώτηση που ένας συνάδελφος μου έθεσε ήταν η αφορμή για αυτό το tip of the day. Η ερώτηση του ήταν: Πως μπορώ να αλλάξω το schema σε ένα object μέσα σε μια database; Η απάντηση είναι απλή και φαίνεται στο παρακάτω παράδειγμα περισσότερα...
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Via trial and error, I recently found out that when creating a Uri combining another Uri and a suffix part (tried at Silverlight, but I guess it’s a .NET issue in general), it eats up the last part of the (first) Uri if it doesn’t end with "/". That is, if you combine http://test.com/a with [...]...
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In this post I would like to demonstrate with a hands-on example how to use the new THROW statement available to us for error handling in SQL Server 2012. Well, most of you know that we have TRY-CATCH statements for exception handling since SQL Server 2005.I have blogged about error handling and exceptions in this post. ( read more )...
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In this post I would like to demonstrate with a few examples how to use the new DMOs (Dynamic Management Objects – DMVs & DMFs) that are available to us with the RTM version of SQL Server 2012.Some of them were present in SQL Server 2008 R2 SP1 but I do not know how many people have noticed their existence. ( read more )...
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In this post I would like to provide you with a hands-on example on how to perform a Page Restore using the SSMS in SQL Server 2012.We could perform page restores in SQL Server 2005/2008 (with T-SQL ) but in SQL Server 2012 we have SSMS UI support for the Page Restore operation.The Page Restore operation is intended for repairing isolated damaged pages. ( read more )...
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Αρκετές φορές έχω αναφέρει κατά την διάρκεια των μαθημάτων και των παρουσιάσεων που κάνω για την αρχιτεκτονική μιας βάσης, ότι τα data files χωρίζονται σε σελίδες των 8K, κάθε 8 τέτοιες σελίδες αποτελούν ένα extent και ότι υπάρχουν δύο είδη extent τα uniform και τα mixed. Uniform είναι αυτά που οι 8 σελίδες τους ανήκουν σε ένα object πχ στον πίνακα των πελατών, ενώ mixed είναι αυτά που οι 8 σελίδες τους ανήκουν σε διαφορετικά. Επανειλημμένα έχω αναφέρει ότι σε κάθε πίνακα οι πρώτες 8 σελίδες του ανήκουν σε mixed extend και από την 9 και μετά πάνε σε uniform extent. Είναι αρκετά χρήσιμο να γνωρίζω το πως έχει γίνει αυτή κατανομή των σελίδων σε extents καθώς θα με βοηθήσει να καταλάβω το πως θα διαβαστούν τα δεδομένα μου αλλά και να μπορώ να καταλάβω το πιθανό fragmentation που θα εμφανιστεί. Τι κάνει η DBCC EXTENTINFO; Για όλους αυτούς του λόγους είναι χρήσιμο να γνωρίζω την ύπαρξη της DBCC EXTENTINFO. Η συγκεκριμένη ανήκει στην κατηγορία των undocumented dbcc commands, αλλά είναι γνωστή σε όσους ασχολούνται συστηματικά...
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In this post I will explain when the actual caching (the stored procedure is placed in the procedure cache ) takes place. Many people think that the execution plan of a stored procedure is cached in the procedure cache when the stored procedure is created. That is a mistake.( read more )...
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In this post Ι would like to demonstrate with a hands-on example the negative performance implications when using built-in or user defined functions in a WHERE statement of a SQL query. ( read more )...
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In this rather short post , I would like to talk about a very handy and easy to use tool (SQL Space Map) that makes it very easy to identify space utilisation for a particular database in our SQL Server instance. ( read more )...
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In this post I would like to talk about various reports ( SQL Server 2012 Performance Dashboard Reports ) that are available to us (through Microsoft Download) and their purpose is to give us an overview of the overall performance of an SQL Server instance.Basically they can help us identify where bottlenecks (CPU,IO) can be found.These reports identify where blocking occurs (waits-latches).You do not have to install SQL Server Reporting Services in order to use these reports.They retrieve all the data they present us through DMVs. ( read more )...
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Crossfilter is a JavaScript library for exploring large multivariate datasets in the browser. Crossfilter supports extremely fast (<30ms) interaction with coordinated views, even with datasets containing a million or more records; Since most interactions only involve a single dimension, and then only small adjustments are made to the filter values, incremental filtering and reducing is [...]...
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Φαντάζομαι ότι σε όλους είναι γνωστό ότι για να εκτελεστεί ένα query στον SQL Server περνάει από τον Query Optimizer. Αυτός για να παράξει το execution plan βλέπει τα index statistics. Αυτό σημαίνει ότι όσο καλύτερα ενημερωμένα είναι αυτά τόσο καλύτερα αποτελέσματα θα δώσει ο Query Optimizer. Πότε όμως αυτά έχουν ενημερωθεί τελευταία φορά; Αν κάποιος θέλει να δώσει απάντηση στο ερώτημα του αυτό δεν έχει παρά να εκτελέσει το παρακάτω query στην βάση του. περισσότερα...
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Όπως εδώ και καιρό έχει γίνει γνωστό από την ανακοίνωση της Microsoft ο SQL Server 2012 θα είναι η τελευταία έκδοση που θα υποστηρίζει τον SQL Server Native Client OLE DB provider καθώς αυτός θα πρόκειται να σταματήσει να αναπτύσσεται. Ο αντικαταστάτης του θα είναι ένας παλιός γνώριμος το ODBC read more...
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I will be writing a new series of posts about the new T-SQL functions that are available to us in SQL Server 2012. In this rather sort post I will demonstrate with hands-on examples how to use the new string function,CONCAT(). ( read more )...
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