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  • Does variable name length matter for performance C#?

    - by MadBoy
    I've been wondering if using long descriptive variable names in WinForms C# matters for performance? I'm asking this question since in AutoIt v3 (interpreted language) it was brought up that having variables with short names like aa instead of veryLongVariableName is much much faster (when program is bigger then 5 liner). I'm wondering if it's the same in C#?

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  • Symmetric Encryption: Performance Questions

    - by cam
    Does the performance of a symmetric encryption algorithm depend on the amount of data being encrypted? Suppose I have about 1000 bytes I need to send over the network rapidly, is it better to encrypt 50 bytes of data 20 times, or 1000 bytes at once? Which will be faster? Does it depend on the algorithm used? If so, what's the highest performing, most secure algorithm for amounts of data under 512 bytes?

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  • Performance - FunctionCall vs Event vs Action vs Delegate

    - by hwcverwe
    Currently I am using Microsoft Sync Framework to synchronize databases. I need to gather information per record which is inserted/updated/deleted by Microsoft Sync Framework and do something with this information. The sync speed can go over 50.000 records per minute. So that means my additional code need to be very lightweight otherwise it will be a huge performance penalty. Microsoft Sync Framework raises an SyncProgress event for each record. I am subscribed to that code like this: // Assembly1 SyncProvider.SyncProgress += OnSyncProgress; // .... private void OnSyncProgress(object sender, DbSyncProgressEventArgs e) { switch (args.Stage) { case DbSyncStage.ApplyingInserts: // MethodCall/Delegate/Action<>/EventHandler<> => HandleInsertedRecordInformation // Do something with inserted record info break; case DbSyncStage.ApplyingUpdates: // MethodCall/Delegate/Action<>/EventHandler<> => HandleUpdatedRecordInformation // Do something with updated record info break; case DbSyncStage.ApplyingDeletes: // MethodCall/Delegate/Action<>/EventHandler<> => HandleDeletedRecordInformation // Do something with deleted record info break; } } Somewhere else in another assembly I have three methods: // Assembly2 public class SyncInformation { public void HandleInsertedRecordInformation(...) {...} public void HandleUpdatedRecordInformation(...) {...} public void HandleInsertedRecordInformation(...) {...} } Assembly2 has a reference to Assembly1. So Assembly1 does not know anything about the existence of the SyncInformation class which need to handle the gathered information. So I have the following options to trigger this code: use events and subscribe on it in Assembly2 1.1. EventHandler< 1.2. Action< 1.3. Delegates using dependency injection: public class Assembly2.SyncInformation : Assembly1.ISyncInformation Other? I know the performance depends on: OnSyncProgress switch using a method call, delegate, Action< or EventHandler< Implementation of SyncInformation class I currently don't care about the implementation of the SyncInformation class. I am mainly focused on the OnSyncProgress method and how to call the SyncInformation methods. So my questions are: What is the most efficient approach? What is the most in-efficient approach? Is there a better way than using a switch in OnSyncProgress?

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  • Performance analysis for java application

    - by user1827614
    I want to do a performance measurement of my application and would like to be able to configure the stats for specific module like (enable for specific module and disable for some) and I want to measure things like memory usage, threads, average band width etc.. Can any one suggest something please, I am new to this. I think Visual VM is good but it doesnot support configuring for different modules. Does Perf4j or Admin4j work here? any one has used these before?

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  • Performance problems loading XML with SSIS, an alternative way!

    - by AtulThakor
    I recently needed to load several thousand XML files into a SQL database, I created an SSIS package which was created as followed: Using a foreach container to loop through a directory and load each file path into a variable, the “Import XML” dataflow would then load each XML file into a SQL table.       Running this, it took approximately 1 second to load each file which seemed a massive amount of time to parse the XML and load the data, speaking to my colleague Martin Croft, he suggested the use of T-SQL Bulk Insert and OpenRowset, so we adjusted the package as followed:     The same foreach container was used but instead the following SQL command was executed (this is an expression):     "INSERT INTO MyTable(FileDate) SELECT   CAST(bulkcolumn AS XML)     FROM OPENROWSET(         BULK         '" + @[User::CurrentFile]  + "',         SINGLE_BLOB ) AS x"     Using this method we managed to load approximately 20 records per second, much faster…for data loading! For what we wanted to achieve this was perfect but I’ll leave you with the following points when making your own decision on which solution you decide to choose!      Openrowset Method Much faster to get the data into SQL You’ll need to parse or create a view over the XML data to allow the data to be more usable(another post on this!) Not able to apply validation/transformation against the data when loading it The SQL Server service account will need permission to the file No schema validation when loading files SSIS Slower (in our case) Schema validation Allows you to apply transformations/joins to the data Permissions should be less of a problem Data can be loaded into the final form through the package When using a schema validation errors can fail the package (I’ll do another post on this)

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  • What will be a good python script (or your favorite language goes here) to test a system's performance and capabilities?

    - by dassouki
    Let's say you're in a computer store looking at 10 laptops, you want to really compare the system's capabilities. What will be an efficient "your fav language goes here" script that will allow you to do this? As an example, when I go to the store I usually open a macbook and a pro's terminal and write an equation in python, iterate it a million or so times, and time them. I like to compare the difference in time. What would be an ideal and simple script that can efficiently compare systems?

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  • Horrorble performance using ListViews with nested objects in WPF

    - by Christian
    Hi community, like mentioned in the title I get a horrible performance if I use ListViews with nested objects. My scenario is: Each row of a ListView presents an object of the class Transaction with following attributes: private int mTransactionID; private IBTTransactionSender mSender; private IBTTransactionReceiver mReceiver; private BTSubstrate mSubstrate; private double mAmount; private string mDeliveryNote; private string mNote; private DateTime mTransactionDate; private DateTime mCreationTimestamp; private BTEmployee mEmployee; private bool mImported; private bool mDescendedFromRecurringTransaction; Each attribute can be accessed by its corresponding property. An ObservableCollection<Transaction> is bound to the ItemsSource of a ListView. The ListView itself looks like the following: </ListView.GroupStyle> <ListView.View> <GridView> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.ToSave" Width="80"> <GridViewColumnHeader Name="GVCHLoadedToSave" Style="{StaticResource ListViewHeaderStyle}">Speichern</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <CheckBox Name="CBListViewItem" IsChecked="{Binding Path=Transaction.ToSave, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></CheckBox> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.TransactionDate" Width="80"> <GridViewColumnHeader Name="GVCHLoadedDate" Style="{StaticResource ListViewHeaderStyle}">Datum</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding ElementName=DPDate, Path=Text}" Style="{StaticResource GridBlockStyle}"/> <toolkit:DatePicker Name="DPDate" Width="{Binding ElementName=GVCHDate, Path=ActualWidth}" SelectedDateFormat="Short" Style="{StaticResource GridEditStyle}" SelectedDate="{Binding Path=Transaction.TransactionDate, Mode=TwoWay}" SelectedDateChanged="DPDate_SelectedDateChanged"/> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Sender.Description" Width="120"> <GridViewColumnHeader Name="GVCHLoadedSender" Style="{StaticResource ListViewHeaderStyle}">Von</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Sender.Description}" Style="{StaticResource GridBlockStyle}"/> <ComboBox Name="CBSender" Width="{Binding ElementName=GVCHSender, Path=ActualWidth}" SelectedItem="{Binding Path=Transaction.Sender}" DisplayMemberPath="Description" Text="{Binding Path=Sender.Description, Mode=OneWay}" ItemsSource="{Binding ElementName=Transaction, Path=SenderList}" Style="{StaticResource GridEditStyle}"> </ComboBox> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Receiver.Description" Width="120"> <GridViewColumnHeader Name="GVCHLoadedReceiver" Style="{StaticResource ListViewHeaderStyle}">Nach</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Receiver.Description}" Style="{StaticResource GridBlockStyle}"/> <ComboBox Name="CBReceiver" Width="{Binding ElementName=GVCHReceiver, Path=ActualWidth}" SelectedItem="{Binding Path=Transaction.Receiver}" DisplayMemberPath="Description" Text="{Binding Path=Receiver.Description, Mode=OneWay}" ItemsSource="{Binding ElementName=Transaction, Path=ReceiverList}" Style="{StaticResource GridEditStyle}"> </ComboBox> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Substrate.Description" Width="140"> <GridViewColumnHeader Name="GVCHLoadedSubstrate" Style="{StaticResource ListViewHeaderStyle}">Substrat</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Substrate.Description}" Style="{StaticResource GridBlockStyle}"/> <ComboBox Name="CBSubstrate" Width="{Binding ElementName=GVCHSubstrate, Path=ActualWidth}" SelectedItem="{Binding Path=Transaction.Substrate}" DisplayMemberPath="Description" Text="{Binding Path=Substrate.Description, Mode=OneWay}" ItemsSource="{Binding ElementName=Transaction, Path=SubstrateList}" Style="{StaticResource GridEditStyle}"> </ComboBox> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Amount" Width="80"> <GridViewColumnHeader Name="GVCHLoadedAmount" Style="{StaticResource ListViewHeaderStyle}">Menge [kg]</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Amount}" Style="{StaticResource GridBlockStyle}"/> <TextBox Name="TBAmount" Text="{Binding Path=Transaction.Amount, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="{Binding ElementName=GVCHAmount, Path=ActualWidth}" Style="{StaticResource GridTextBoxStyle}" /> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.DeliveryNote" Width="100"> <GridViewColumnHeader Name="GVCHLoadedDeliveryNote" Style="{StaticResource ListViewHeaderStyle}">Lieferschein Nr.</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.DeliveryNote}" Style="{StaticResource GridBlockStyle}"/> <TextBox Name="TBDeliveryNote" Text="{Binding Path=Transaction.DeliveryNote, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="{Binding ElementName=GVCHDeliveryNote, Path=ActualWidth}" Style="{StaticResource GridEditStyle}" /> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Note" Width="190"> <GridViewColumnHeader Name="GVCHLoadedNote" Style="{StaticResource ListViewHeaderStyle}">Bemerkung</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Note}" Style="{StaticResource GridBlockStyle}"/> <TextBox Name="TBNote" Text="{Binding Path=Transaction.Note, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="{Binding ElementName=GVCHNote, Path=ActualWidth}" Style="{StaticResource GridEditStyle}" /> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> <GridViewColumn core:SortableListView.SortPropertyName="Transaction.Employee.LastName" Width="100"> <GridViewColumnHeader Name="GVCHLoadedEmployee" Style="{StaticResource ListViewHeaderStyle}">Mitarbeiter</GridViewColumnHeader> <GridViewColumn.CellTemplate> <DataTemplate> <Grid> <TextBlock Text="{Binding Path=Transaction.Employee.LastName}" Style="{StaticResource GridBlockStyle}"/> <ComboBox Name="CBEmployee" Width="{Binding ElementName=GVCHEmployee, Path=ActualWidth}" SelectedItem="{Binding Path=Transaction.Employee}" DisplayMemberPath="LastName" Text="{Binding Path=Employee.LastName, Mode=OneWay}" ItemsSource="{Binding ElementName=Transaction, Path=EmployeeList}" Style="{StaticResource GridEditStyle}"> </ComboBox> </Grid> </DataTemplate> </GridViewColumn.CellTemplate> </GridViewColumn> </GridView> </ListView.View> </ListView> As you can see in the screenshot the user got the possibility to change the values of the transaction attributes with comboboxes. Ok now to my problem. If I click on the "Laden" button the application will load about 150 entries in the ObservableCollection<Transaction>. Before I fill the collection I set the ItemsSource of the ListView to null and after filling I bind the collection to the ItemsSource once again. The loading itself takes a few milliseconds, but the rendering of the filled collection takes a long time (150 entries = about 20 sec). I tested to delete all Comboboxes out of the xaml and i got a better performance, because I don't have to fill the ComboBoxes for each row. But I need to have these comboboxes for modifing the attributes of the Transaction. Does anybody know how to improve the performance? THX

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  • Performance surprise with "as" and nullable types

    - by Jon Skeet
    I'm just revising chapter 4 of C# in Depth which deals with nullable types, and I'm adding a section about using the "as" operator, which allows you to write: object o = ...; int? x = o as int?; if (x.HasValue) { ... // Use x.Value in here } I thought this was really neat, and that it could improve performance over the C# 1 equivalent, using "is" followed by a cast - after all, this way we only need to ask for dynamic type checking once, and then a simple value check. This appears not to be the case, however. I've included a sample test app below, which basically sums all the integers within an object array - but the array contains a lot of null references and string references as well as boxed integers. The benchmark measures the code you'd have to use in C# 1, the code using the "as" operator, and just for kicks a LINQ solution. To my astonishment, the C# 1 code is 20 times faster in this case - and even the LINQ code (which I'd have expected to be slower, given the iterators involved) beats the "as" code. Is the .NET implementation of isinst for nullable types just really slow? Is it the additional unbox.any that causes the problem? Is there another explanation for this? At the moment it feels like I'm going to have to include a warning against using this in performance sensitive situations... Results: Cast: 10000000 : 121 As: 10000000 : 2211 LINQ: 10000000 : 2143 Code: using System; using System.Diagnostics; using System.Linq; class Test { const int Size = 30000000; static void Main() { object[] values = new object[Size]; for (int i = 0; i < Size - 2; i += 3) { values[i] = null; values[i+1] = ""; values[i+2] = 1; } FindSumWithCast(values); FindSumWithAs(values); FindSumWithLinq(values); } static void FindSumWithCast(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { if (o is int) { int x = (int) o; sum += x; } } sw.Stop(); Console.WriteLine("Cast: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithAs(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = 0; foreach (object o in values) { int? x = o as int?; if (x.HasValue) { sum += x.Value; } } sw.Stop(); Console.WriteLine("As: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } static void FindSumWithLinq(object[] values) { Stopwatch sw = Stopwatch.StartNew(); int sum = values.OfType<int>().Sum(); sw.Stop(); Console.WriteLine("LINQ: {0} : {1}", sum, (long) sw.ElapsedMilliseconds); } }

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  • Application Performance Episode 2: Announcing the Judges!

    - by Michaela Murray
    The story so far… We’re writing a new book for ASP.NET developers, and we want you to be a part of it! If you work with ASP.NET applications, and have top tips, hard-won lessons, or sage advice for avoiding, finding, and fixing performance problems, we want to hear from you! And if your app uses SQL Server, even better – interaction with the database is critical to application performance, so we’re looking for database top tips too. There’s a Microsoft Surface apiece for the person who comes up with the best tip for SQL Server and the best tip for .NET. Of course, if your suggestion is selected for the book, you’ll get full credit, by name, Twitter handle, GitHub repository, or whatever you like. To get involved, just email your nuggets of performance wisdom to [email protected] – there are examples of what we’re looking for and full competition details at Application Performance: The Best of the Web. Enter the judges… As mentioned in my last blogpost, we have a mystery panel of celebrity judges lined up to select the prize-winning performance pointers. We’re now ready to reveal their secret identities! Judging your ASP.NET  tips will be: Jean-Phillippe Gouigoux, MCTS/MCPD Enterprise Architect and MVP Connected System Developer. He’s a board member at French software company MGDIS, and teaches algorithms, security, software tests, and ALM at the Université de Bretagne Sud. Jean-Philippe also lectures at IT conferences and writes articles for programming magazines. His book Practical Performance Profiling is published by Simple-Talk. Nik Molnar,  a New Yorker, ASP Insider, and co-founder of Glimpse, an open source ASP.NET diagnostics and debugging tool. Originally from Florida, Nik specializes in web development, building scalable, client-centric solutions. In his spare time, Nik can be found cooking up a storm in the kitchen, hanging with his wife, speaking at conferences, and working on other open source projects. Mitchel Sellers, Microsoft C# and DotNetNuke MVP. Mitchel is an experienced software architect, business leader, public speaker, and educator. He works with companies across the globe, as CEO of IowaComputerGurus Inc. Mitchel writes technical articles for online and print publications and is the author of Professional DotNetNuke Module Programming. He frequently answers questions on StackOverflow and MSDN and is an active participant in the .NET and DotNetNuke communities. Clive Tong, Software Engineer at Red Gate. In previous roles, Clive spent a lot of time working with Common LISP and enthusing about functional languages, and he’s worked with managed languages since before his first real job (which was a long time ago). Long convinced of the productivity benefits of managed languages, Clive is very interested in getting good runtime performance to keep managed languages practical for real-world development. And our trio of SQL Server specialists, ready to select your top suggestion, are (drumroll): Rodney Landrum, a SQL Server MVP who writes regularly about Integration Services, Analysis Services, and Reporting Services. He’s authored SQL Server Tacklebox, three Reporting Services books, and contributes regularly to SQLServerCentral, SQL Server Magazine, and Simple–Talk. His day job involves overseeing a large SQL Server infrastructure in Orlando. Grant Fritchey, Product Evangelist at Red Gate and SQL Server MVP. In an IT career spanning more than 20 years, Grant has written VB, VB.NET, C#, and Java. He’s been working with SQL Server since version 6.0. Grant volunteers with the Editorial Committee at PASS and has written books for Apress and Simple-Talk. Jonathan Allen, leader and founder of the PASS SQL South West user group. He’s been working with SQL Server since 1999 and enjoys performance tuning, development, and using SQL Server for business solutions. He’s spoken at SQLBits and SQL in the City, as well as local user groups across the UK. He’s also a moderator at ask.sqlservercentral.com.

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  • Why do Scala maps have poor performance relative to Java?

    - by Mike Hanafey
    I am working on a Scala app that consumes large amounts of CPU time, so performance matters. The prototype of the system was written in Python, and performance was unacceptable. The application does a lot with inserting and manipulating data in maps. Rex Kerr's Thyme was used to look at the performance of updating and retrieving data from maps. Basically "n" random Ints were stored in maps, and retrieved from the maps, with the time relative to java.util.HashMap used as a reference. The full results for a range of "n" are here. Sample (n=100,000) performance relative to java, smaller is worse: Update Read Mutable 16.06% 76.51% Immutable 31.30% 20.68% I do not understand why the scala immutable map beats the scala mutable map in update performance. Using the sizeHint on the mutable map does not help (it appears to be ignored in the tested implementation, 2.10.3). Even more surprisingly the immutable read performance is worse than the mutable read performance, more significantly so with larger maps. The update performance of the scala mutable map is surprisingly bad, relative to both scala immutable and plain Java. What is the explanation?

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  • WPF Binding Failure performance hit vs Exception

    - by Aran Mulholland
    when we bind to heterogeneous collection of objects, not all objects have the same set of properties. in the output window we get a message like: System.Windows.Data Error: 39 : BindingExpression path error: 'RoundingFactor' property not found on 'object' ''MultiLineTextMarkingScheme' (HashCode=7262386)'. BindingExpression:Path=RoundingFactor;.......... This doesn't appear to be an exception, but we are concerned it has a performance impact. Should we be concerned and create a view model that has all the properties we wish to bind to (and have the properties that dont exist on the underlying element return null) or can we just leave it. This situation often occurs in a grid scenario where there might be large numbers of these binding failures.

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  • HashSet vs. List performance

    - by Michael Damatov
    It's clear that a search performance of the generic HashSet<T> class is higher than of the generic List<T> class. Just compare the hash-based key with the linear approach in the List<T> class. However calculating a hash key may itself take some CPU cycles, so for a small amount of items the linear search can be a real alternative to the HashSet<T>. My question: where is the break-even? To simplify the scenario (and to be fair) let's assume that the List<T> class uses the element's Equals() method to identify an item.

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  • Android Map Performance poor because of many Overlays?

    - by Dave
    Hi, I have a map in my android application that shows many markers (~20-50). But the app performs very poor when i try to scroll/zoom (in Google Android Maps i did a sample search for pizza and there were also some 20-50 results found and i didn't notice any particular performance problems when zooming/scrolling through the map). Here is my (pseudo)code: onCreate() { .... drawable = this.getResources().getDrawable(R.drawable.marker1); itemizedOverlay = new MyItemizedOverlay(drawable,mapView); ... callWebServiceToRetrieveData(); createMarkers(); } createMarkers(){ for(elem:bigList){ GeoPoint geoPoint = new GeoPoint((int)(elem.getLat()*1000000), (int) (elem.getLon()*1000000)); OverlayItem overlayItem = new OverlayItem(geoPoint, elem.getName(), elem.getData()); itemizedOverlay.addOverlay(overlayItem); mapOverlays.add(itemizedOverlay); } mapView.invalidate(); } the MyItemizedOverlay.addOverlay looks like this: public void addOverlay(OverlayItem overlay) { m_overlays.add(overlay); populate(); }

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  • How to Avoid Your Next 12-Month Science Project

    - by constant
    While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack. After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades? On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea. Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company. Engineering Systems is Hard Work! The backbone of Exalogic is its InfiniBand network: 4 times better bandwidth than even 10 Gigabit Ethernet, and only about a tenth of its latency. What a potential for increased scalability and throughput across the middleware and database layers! But InfiniBand is a beast that needs to be tamed: It is true that Exalogic uses a standard, open-source Open Fabrics Enterprise Distribution (OFED) InfiniBand driver stack. Unfortunately, this software has been developed by the HPC community with fastest speed in mind (which is good) but, despite the name, not many other enterprise-class requirements are included (which is less good). Here are some of the improvements that Oracle's InfiniBand development team had to add to the OFED stack to make it enterprise-ready, simply because typical HPC users didn't have the need to implement them: More than 100 bug fixes in the pieces that were not related to the Message Passing Interface Protocol (MPI), which is the protocol that HPC users use most of the time, but which is less useful in the enterprise. Performance optimizations and tuning across the whole IB stack: From Switches, Host Channel Adapters (HCAs) and drivers to low-level protocols, middleware and applications. Yes, even the standard HPC IB stack could be improved in terms of performance. Ethernet over IB (EoIB): Exalogic uses InfiniBand internally to reach high performance, but it needs to play nicely with datacenters around it. That's why Oracle added Ethernet over InfiniBand technology to it that allows for creating many virtual 10GBE adapters inside Exalogic's nodes that are aggregated and connected to Exalogic's IB gateway switches. While this is an open standard, it's up to the vendor to implement it. In this case, Oracle integrated the EoIB stack with Oracle's own IB to 10GBE gateway switches, and made it fully virtualized from the beginning. This means that Exalogic customers can completely rewire their server infrastructure inside the rack without having to physically pull or plug a single cable - a must-have for every cloud deployment. Anybody who wants to match this level of integration would need to add an InfiniBand switch development team to their project. Or just buy Oracle's gateway switches, which are conveniently shipped with a whole server infrastructure attached! IPv6 support for InfiniBand's Sockets Direct Protocol (SDP), Reliable Datagram Sockets (RDS), TCP/IP over IB (IPoIB) and EoIB protocols. Because no IPv6 = not very enterprise-class. HA capability for SDP. High Availability is not a big requirement for HPC, but for enterprise-class application servers it is. Every node in Exalogic's InfiniBand network is connected twice for redundancy. If any cable or port or HCA fails, there's always a replacement link ready to take over. This requires extra magic at the protocol level to work. So in addition to Weblogic's failover capabilities, Oracle implemented IB automatic path migration at the SDP level to avoid unnecessary failover operations at the middleware level. Security, for example spoof-protection. Another feature that is less important for traditional users of InfiniBand, but very important for enterprise customers. InfiniBand Partitioning and Quality-of-Service (QoS): One of the first questions we get from customers about Exalogic is: “How can we implement multi-tenancy?” The answer is to partition your IB network, which effectively creates many networks that work independently and that are protected at the lowest networking layer possible. In addition to that, QoS allows administrators to prioritize traffic flow in multi-tenancy environments so they can keep their service levels where it matters most. Resilient IB Fabric Management: InfiniBand is a self-managing network, so a lot of the magic lies in coming up with the right topology and in teaching the subnet manager how to properly discover and manage the network. Oracle's Infiniband switches come with pre-integrated, highly available fabric management with seamless integration into Oracle Enterprise Manager Ops Center. In short: Oracle elevated the OFED InfiniBand stack into an enterprise-class networking infrastructure. Many years and multiple teams of manpower went into the above improvements - this is something you can only get from Oracle, because no other InfiniBand vendor can give you these features across the whole stack! Exabus: Because it's not About the Size of Your Network, it's How You Use it! So let's assume that you somehow were able to get your hands on an enterprise-class IB driver stack. Or maybe you don't care and are just happy with the standard OFED one? Anyway, the next step is to actually leverage that InfiniBand performance. Here are the choices: Use traditional TCP/IP on top of the InfiniBand stack, Develop your own integration between your middleware and the lower-level (but faster) InfiniBand protocols. While more bandwidth is always a good thing, it's actually the low latency that enables superior performance for your applications when running on any networking infrastructure: The lower the latency, the faster the response travels through the network and the more transactions you can close per second. The reason why InfiniBand is such a low latency technology is that it gets rid of most if not all of your traditional networking protocol stack: Data is literally beamed from one region of RAM in one server into another region of RAM in another server with no kernel/drivers/UDP/TCP or other networking stack overhead involved! Which makes option 1 a no-go: Adding TCP/IP on top of InfiniBand is like adding training wheels to your racing bike. It may be ok in the beginning and for development, but it's not quite the performance IB was meant to deliver. Which only leaves option 2: Integrating your middleware with fast, low-level InfiniBand protocols. And this is what Exalogic's "Exabus" technology is all about. Here are a few Exabus features that help applications leverage the performance of InfiniBand in Exalogic: RDMA and SDP integration at the JDBC driver level (SDP), for Oracle Weblogic (SDP), Oracle Coherence (RDMA), Oracle Tuxedo (RDMA) and the new Oracle Traffic Director (RDMA) on Exalogic. Using these protocols, middleware can communicate a lot faster with each other and the Oracle database than by using standard networking protocols, Seamless Integration of Ethernet over InfiniBand from Exalogic's Gateway switches into the OS, Oracle Weblogic optimizations for handling massive amounts of parallel transactions. Because if you have an 8-lane Autobahn, you also need to improve your ramps so you can feed it with many cars in parallel. Integration of Weblogic with Oracle Exadata for faster performance, optimized session management and failover. As you see, “Exabus” is Oracle's word for describing all the InfiniBand enhancements Oracle put into Exalogic: OFED stack enhancements, protocols for faster IB access, and InfiniBand support and optimizations at the virtualization and middleware level. All working together to deliver the full potential of InfiniBand performance. Who else has 100% control over their middleware so they can develop their own low-level protocol integration with InfiniBand? Even if you take an open source approach, you're looking at years of development work to create, test and support a whole new networking technology in your middleware! The Extras: Less Hassle, More Productivity, Faster Time to Market And then there are the other advantages of Engineered Systems that are true for Exalogic the same as they are for every other Engineered System: One simple purchasing process: No headaches due to endless RFPs and no “Will X work with Y?” uncertainties. Everything has been engineered together: All kinds of bugs and problems have been already fixed at the design level that would have only manifested themselves after you have built the system from scratch. Everything is built, tested and integrated at the factory level . Less integration pain for you, faster time to market. Every Exalogic machine world-wide is identical to Oracle's own machines in the lab: Instant replication of any problems you may encounter, faster time to resolution. Simplified patching, management and operations. One throat to choke: Imagine finger-pointing hell for systems that have been put together using several different vendors. Oracle's Engineered Systems have a single phone number that customers can call to get their problems solved. For more business-centric values, read The Business Value of Engineered Systems. Conclusion: Buy Exalogic, or get ready for a 6-12 Month Science Project And here's the reason why it's not easy to "build your own Exalogic": There's a lot of work required to make such a system fly. In fact, anybody who is starting to "just put together a bunch of servers and an InfiniBand network" is really looking at a 6-12 month science project. And the outcome is likely to not be very enterprise-class. And it won't have Exalogic's performance either. Because building an Engineered System is literally rocket science: It takes a lot of time, effort, resources and many iterations of design/test/analyze/fix to build such a system. That's why InfiniBand has been reserved for HPC scientists for such a long time. And only Oracle can bring the power of InfiniBand in an enterprise-class, ready-to use, pre-integrated version to customers, without the develop/integrate/support pain. For more details, check the new Exalogic overview white paper which was updated only recently. P.S.: Thanks to my colleagues Ola, Paul, Don and Andy for helping me put together this article! var flattr_uid = '26528'; var flattr_tle = 'How to Avoid Your Next 12-Month Science Project'; var flattr_dsc = 'While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack.After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades?On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea.Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company.'; var flattr_tag = 'Engineered Systems,Engineered Systems,Infiniband,Integration,latency,Oracle,performance'; var flattr_cat = 'text'; var flattr_url = 'http://constantin.glez.de/blog/2012/04/how-avoid-your-next-12-month-science-project'; var flattr_lng = 'en_GB'

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  • SQLite INTERSECT gives a huge performance decrease

    - by Derk
    I have a query that runs in less than 1 ms: SELECT product_to_value.category AS category, features.name AS featurename, featurevalues.name AS valuename FROM product_to_value, features, featurevalues WHERE product_to_value.category IN(:int, :bla, :bla1) AND product_to_value.feature = features.int AND product_to_value.value = featurevalues.int LIMIT 10 However, when I combine it with another query using INTERSECT, the query now takes more than 250ms: SELECT product_to_value.category AS category, features.name AS featurename, featurevalues.name AS valuename FROM product_to_value, features, featurevalues WHERE product_to_value.category IN(:int, :bla, :bla1) AND product_to_value.feature = features.int AND product_to_value.value = featurevalues.int INTERSECT SELECT product_to_value.category AS category, features.name AS featurename, featurevalues.name AS valuename FROM product_to_value, features, featurevalues WHERE product_to_value.category IN(:int, :bla, :bla1) AND product_to_value.feature = features.int AND product_to_value.value = featurevalues.int LIMIT 10 This can't be right. I've tried several index combinations, for example an index on all columns I use in my query, but to no avail. I've tried compound indexes as well, but they only slow things down even more. I have read a few things about SQLite and how it treats indexes. I know SQLite is capable of delivering sick performance, and surely I must be overlooking something.

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  • Oracle Database 12c Spatial: Vector Performance Acceleration

    - by Okcan Yasin Saygili-Oracle
    Most business information has a location component, such as customer addresses, sales territories and physical assets. Businesses can take advantage of their geographic information by incorporating location analysis and intelligence into their information systems. This allows organizations to make better decisions, respond to customers more effectively, and reduce operational costs – increasing ROI and creating competitive advantage. Oracle Database, the industry’s most advanced database,  includes native location capabilities, fully integrated in the kernel, for fast, scalable, reliable and secure spatial and massive graph applications. It is a foundation for deploying enterprise-wide spatial information systems and locationenabled business applications. Developers can extend existing Oracle-based tools and applications, since they can easily incorporate location information directly in their applications, workflows, and services. Spatial Features The geospatial data features of Oracle Spatial and Graph option support complex geographic information systems (GIS) applications, enterprise applications and location services applications. Oracle Spatial and Graph option extends the spatial query and analysis features included in every edition of Oracle Database with the Oracle Locator feature, and provides a robust foundation for applications that require advanced spatial analysis and processing in the Oracle Database. It supports all major spatial data types and models, addressing challenging business-critical requirements from various industries, including transportation, utilities, energy, public sector, defense and commercial location intelligence. Network Data Model Graph Features The Network Data Model graph explicitly stores and maintains a persistent data model withnetwork connectivity and provides network analysis capability such as shortest path, nearest neighbors, within cost and reachability. It loads partitioned networks into memory on demand, overcomingthe limitations of in-memory analysis. Partitioning massive networks into manageable sub-networkssimplifies the network analysis. RDF Semantic Graph Features RDF Semantic Graph has native support for World Wide Web Consortium standards. It has open, scalable, and secure features for storing RDF/OWL ontologies anddata; native inference with OWL 2, SKOS and user-defined rules; and querying RDF/OWL data withSPARQL 1.1, Java APIs, and SPARQLgraph patterns in SQL. Video: Oracle Spatial and Graph Overview Oracle spatial is embeded on oracle database product. So ,we can use oracle installer (OUI).The Oracle Universal Installer (OUI) is used to install Oracle Database software. OUI is a graphical user interface utility that enables you to view the Oracle software that is installed on your machine, install new Oracle Database software, and delete Oracle software that you no longer need to use. Online Help is available to guide you through the installation process. One of the installation options is to create a database. If you select database creation, OUI automatically starts Oracle Database Configuration Assistant (DBCA) to guide you through the process of creating and configuring a database. If you do not create a database during installation, you must invoke DBCA after you have installed the software to create a database. You can also use DBCA to create additional databases. For installing Oracle Database 12c you may check the Installing Oracle Database Software and Creating a Database tutorial under the Oracle Database 12c 2-Day DBA Series.You can always check if spatial is available in your database using  "select comp_id, version, status, comp_name from dba_registry where comp_id='SDO';"   One of the most notable improvements with Oracle Spatial and Graph 12c can be seen in performance increases in vector data operations. Enabling the Spatial Vector Acceleration feature (available with the Spatial option) dramatically improves the performance of commonly used vector data operations, such as sdo_distance, sdo_aggr_union, and sdo_inside. With 12c, these operations also run more efficiently in parallel than in prior versions through the use of metadata caching. For organizations that have been facing processing limitations, these enhancements enable developers to make a small set of configuration changes and quickly realize significant performance improvements. Results include improved index performance, enhanced geometry engine performance, optimized secondary filter optimizations for Spatial operators, and improved CPU and memory utilization for many advanced vector functions. Vector performance acceleration is especially beneficial when using Oracle Exadata Database Machine and other large-scale systems. Oracle Spatial and Graph vector performance acceleration builds on general improvements available to all SDO_GEOMETRY operations in these areas: Caching of index metadata, Concurrent update mechanisms, and Optimized spatial predicate selectivity and cost functions. These optimizations enable more efficient use of: CPU, Memory, and Partitioning Resulting in substantial query performance improvements.UsageTo accelerate the performance of spatial operators, it is recommended that you set the SPATIAL_VECTOR_ACCELERATION database system parameter to the value TRUE. (This parameter is authorized for use only by licensed Oracle Spatial users, and its default value is FALSE.) You can set this parameter for the whole system or for a single session. To set the value for the whole system, do either of the following:Enter the following statement from a suitably privileged account:   ALTER SYSTEM SET SPATIAL_VECTOR_ACCELERATION = TRUE;Add the following to the database initialization file (xxxinit.ora):   SPATIAL_VECTOR_ACCELERATION = TRUE;To set the value for the current session, enter the following statement from a suitably privileged account:   ALTER SESSION SET SPATIAL_VECTOR_ACCELERATION = TRUE; Checkout the complete list of new features on Oracle.com @ http://www.oracle.com/technetwork/database/options/spatialandgraph/overview/index.html Spatial and Graph Data Sheet (PDF) Spatial and Graph White Paper (PDF)

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