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  • Define a positive number to be isolated if none of the digits in its square are in its cube [closed]

    - by proglaxmi
    Define a positive number to be isolated if none of the digits in its square are in its cube. For example 163 is n isolated number because 69*69 = 26569 and 69*69*69 = 4330747 and the square does not contain any of the digits 0, 3, 4 and 7 which are the digits used in the cube. On the other hand 162 is not an isolated number because 162*162=26244 and 162*162*162 = 4251528 and the digits 2 and 4 which appear in the square are also in the cube. Write a function named isIsolated that returns 1 if its argument is an isolated number, it returns 0 if its not an isolated number and it returns -1 if it cannot determine whether it is isolated or not (see the note below). The function signature is: int isIsolated(long n) Note that the type of the input parameter is long. The maximum positive number that can be represented as a long is 63 bits long. This allows us to test numbers up to 2,097,151 because the cube of 2,097,151 can be represented as a long. However, the cube of 2,097,152 requires more than 63 bits to represent it and hence cannot be computed without extra effort. Therefore, your function should test if n is larger than 2,097,151 and return -1 if it is. If n is less than 1 your function should also return -1. Hint: n % 10 is the rightmost digit of n, n = n/10 shifts the digits of n one place to the right. The first 10 isolated numbers are N n*n n*n*n 2 4 8 3 9 27 8 64 512 9 81 729 14 196 2744 24 576 13824 28 784 21952 34 1156 39304 58 3364 195112 63 3969 250047

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  • Shell halts while looping and 'transforming' values in dictionary (Python 2.7.5)

    - by Gus
    I'm building a program that will sum digits in a given list in a recursive way. Say, if the source list has 10 elements, the second list will have 9, the third 8 and so on until the last list that will have only one element. This is done by adding the first element to the second, then the second to the third and so on. I'm stuck without feedback from the shell. It halts without throwing any errors, then in a couple of seconds the fan is spinning like crazy. I've read quite a few posts here and changed my approach, but I'm not sure that what have so far can produce the results I'm looking for. Thanks in advance: #--------------------------------------------------- #functions #--------------------------------------------------- #sum up pairs in a list def reduce(inputList): i = 0 while (i < len(inputList)): #ref to current and next item j = i + 1 #don't go for the last item if j != len(inputList): #new number eq current + next number newNumber = inputList[i] + inputList[j] if newNumber >= 10: #reduce newNumber to single digit newNumber = sum(map(int, str(newNumber))) #collect into temp list outputList.append(newNumber) i = i + 1 return outputList; #--------------------------------------------------- #program starts here #--------------------------------------------------- outputList = [] sourceList = [7, 3, 1, 2, 1, 4, 6] counter = len(sourceList) dict = {} dict[0] = sourceList print '-------------' print 'Level 0:', dict[0] for i in range(counter): j = i + 1 if j != counter: baseList = dict.get(i) #check function to understand what it does newList = reduce(baseList) #new key and value from previous/transformed value dict[j] = newList print 'Level %d: %s' % (j, dict[j])

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  • PHP- Display days weekly by giving 2 dates

    - by librium
    I'd like display dates by week number between giving 2 dates like example below. Is this possible in PHP? if the dates are 2010-12-01 thru 2010-12-19, it will display it as follows. week-1 2010-12-01 2010-12-02 2010-12-03 2010-12-04 2010-12-05 2010-12-06 2010-12-07 week-2 2010-12-08 2010-12-09 2010-12-10 2010-12-11 2010-12-12 2010-12-13 2010-12-14 week-3 2010-12-15 2010-12-16 2010-12-17 2010-12-18 2010-12-19 and so on... I use mysql. It has startdate end enddate fields. thank you in advance. I can get how many weeks in those giving 2 dates and display them using a datediff('ww', '2010-12-01', '2010-12-19', false); I found on the internet. And I can display dates between two dates as follows. But I am having trouble grouping them by week. $sdate = "2010-12-01"; $edate = "2010-12-19"; $days = getDaysInBetween($sdate, $edate); foreach ($days as $val) { echo $val; } function getDaysInBetween($start, $end) { // Vars $day = 86400; // Day in seconds $format = 'Y-m-d'; // Output format (see PHP date funciton) $sTime = strtotime($start); // Start as time $eTime = strtotime($end); // End as time $numDays = round(($eTime - $sTime) / $day) + 1; $days = array(); // Get days for ($d = 0; $d < $numDays; $d++) { $days[] = date($format, ($sTime + ($d * $day))); } // Return days return $days; }

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  • CreationName for SSIS 2008 and adding components programmatically

    If you are building SSIS 2008 packages programmatically and adding data flow components, you will probably need to know the creation name of the component to add. I can never find a handy reference when I need one, hence this rather mundane post. See also CreationName for SSS 2005. We start with a very simple snippet for adding a component: // Add the Data Flow Task package.Executables.Add("STOCK:PipelineTask"); // Get the task host wrapper, and the Data Flow task TaskHost taskHost = package.Executables[0] as TaskHost; MainPipe dataFlowTask = (MainPipe)taskHost.InnerObject; // Add OLE-DB source component - ** This is where we need the creation name ** IDTSComponentMetaData90 componentSource = dataFlowTask.ComponentMetaDataCollection.New(); componentSource.Name = "OLEDBSource"; componentSource.ComponentClassID = "DTSAdapter.OLEDBSource.2"; So as you can see the creation name for a OLE-DB Source is DTSAdapter.OLEDBSource.2. CreationName Reference  ADO NET Destination Microsoft.SqlServer.Dts.Pipeline.ADONETDestination, Microsoft.SqlServer.ADONETDest, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 ADO NET Source Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter, Microsoft.SqlServer.ADONETSrc, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Aggregate DTSTransform.Aggregate.2 Audit DTSTransform.Lineage.2 Cache Transform DTSTransform.Cache.1 Character Map DTSTransform.CharacterMap.2 Checksum Konesans.Dts.Pipeline.ChecksumTransform.ChecksumTransform, Konesans.Dts.Pipeline.ChecksumTransform, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b Conditional Split DTSTransform.ConditionalSplit.2 Copy Column DTSTransform.CopyMap.2 Data Conversion DTSTransform.DataConvert.2 Data Mining Model Training MSMDPP.PXPipelineProcessDM.2 Data Mining Query MSMDPP.PXPipelineDMQuery.2 DataReader Destination Microsoft.SqlServer.Dts.Pipeline.DataReaderDestinationAdapter, Microsoft.SqlServer.DataReaderDest, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Derived Column DTSTransform.DerivedColumn.2 Dimension Processing MSMDPP.PXPipelineProcessDimension.2 Excel Destination DTSAdapter.ExcelDestination.2 Excel Source DTSAdapter.ExcelSource.2 Export Column TxFileExtractor.Extractor.2 Flat File Destination DTSAdapter.FlatFileDestination.2 Flat File Source DTSAdapter.FlatFileSource.2 Fuzzy Grouping DTSTransform.GroupDups.2 Fuzzy Lookup DTSTransform.BestMatch.2 Import Column TxFileInserter.Inserter.2 Lookup DTSTransform.Lookup.2 Merge DTSTransform.Merge.2 Merge Join DTSTransform.MergeJoin.2 Multicast DTSTransform.Multicast.2 OLE DB Command DTSTransform.OLEDBCommand.2 OLE DB Destination DTSAdapter.OLEDBDestination.2 OLE DB Source DTSAdapter.OLEDBSource.2 Partition Processing MSMDPP.PXPipelineProcessPartition.2 Percentage Sampling DTSTransform.PctSampling.2 Performance Counters Source DataCollectorTransform.TxPerfCounters.1 Pivot DTSTransform.Pivot.2 Raw File Destination DTSAdapter.RawDestination.2 Raw File Source DTSAdapter.RawSource.2 Recordset Destination DTSAdapter.RecordsetDestination.2 RegexClean Konesans.Dts.Pipeline.RegexClean.RegexClean, Konesans.Dts.Pipeline.RegexClean, Version=2.0.0.0, Culture=neutral, PublicKeyToken=d1abe77e8a21353e Row Count DTSTransform.RowCount.2 Row Count Plus Konesans.Dts.Pipeline.RowCountPlusTransform.RowCountPlusTransform, Konesans.Dts.Pipeline.RowCountPlusTransform, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b Row Number Konesans.Dts.Pipeline.RowNumberTransform.RowNumberTransform, Konesans.Dts.Pipeline.RowNumberTransform, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b2ab4a111192992b Row Sampling DTSTransform.RowSampling.2 Script Component Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHost, Microsoft.SqlServer.TxScript, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Slowly Changing Dimension DTSTransform.SCD.2 Sort DTSTransform.Sort.2 SQL Server Compact Destination Microsoft.SqlServer.Dts.Pipeline.SqlCEDestinationAdapter, Microsoft.SqlServer.SqlCEDest, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 SQL Server Destination DTSAdapter.SQLServerDestination.2 Term Extraction DTSTransform.TermExtraction.2 Term Lookup DTSTransform.TermLookup.2 Trash Destination Konesans.Dts.Pipeline.TrashDestination.Trash, Konesans.Dts.Pipeline.TrashDestination, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b8351fe7752642cc TxTopQueries DataCollectorTransform.TxTopQueries.1 Union All DTSTransform.UnionAll.2 Unpivot DTSTransform.UnPivot.2 XML Source Microsoft.SqlServer.Dts.Pipeline.XmlSourceAdapter, Microsoft.SqlServer.XmlSrc, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Here is a simple console program that can be used to enumerate the pipeline components installed on your machine, and dumps out a list of all components like that above. You will need to add a reference to the Microsoft.SQLServer.ManagedDTS assembly. using System; using System.Diagnostics; using Microsoft.SqlServer.Dts.Runtime; public class Program { static void Main(string[] args) { Application application = new Application(); PipelineComponentInfos componentInfos = application.PipelineComponentInfos; foreach (PipelineComponentInfo componentInfo in componentInfos) { Debug.WriteLine(componentInfo.Name + "\t" + componentInfo.CreationName); } Console.Read(); } }

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  • Windows Presentation Foundation 4.5 Cookbook Review

    - by Ricardo Peres
    As promised, here’s my review of Windows Presentation Foundation 4.5 Cookbook, that Packt Publishing kindly made available to me. It is an introductory book, targeted at WPF newcomers or users with few experience, following the typical recipes or cookbook style. Like all Packt Publishing books on development, each recipe comes with sample code that is self-sufficient for understanding the concepts it tries to illustrate. It starts on chapter 1 by introducing the most important concepts, the XAML language itself, what can be declared in XAML and how to do it, what are dependency and attached properties as well as markup extensions and events, which should give readers a most required introduction to how WPF works and how to do basic stuff. It moves on to resources on chapter 2, which also makes since, since it’s such an important concept in WPF. Next, chapter 3, come the panels used for laying controls on the screen, all of the out of the box panels are described with typical use cases. Controls come next in chapter 4; the difference between elements and controls is introduced, as well as content controls, headered controls and items controls, and all standard controls are introduced. The book shows how to change the way they look by using templates. The next chapter, 5, talks about top level windows and the WPF application object: how to access startup arguments, how to set the main window, using standard dialogs and there’s even a sample on how to have a irregularly-shaped window. This is one of the most important concepts in WPF: data binding, which is the theme for the following chapter, 6. All common scenarios are introduced, the binding modes, directions, triggers, etc. It talks about the INotifyPropertyChanged interface and how to use it for notifying data binding subscribers of changes in data sources. Data templates and selectors are also covered, as are value converters and data triggers. Examples include master-detail and sorting, grouping and filtering collections and binding trees and grids. Last it covers validation rules and error templates. Chapter 7 talks about the current trend in WPF development, the Model View View-Model (MVVM) framework. This is a well known pattern for connecting things interface to actions, and it is explained competently. A typical implementation is presented which also presents the command pattern used throughout WPF. A complete application using MVVM is presented from start to finish, including typical features such as undo. Style and layout is covered on chapter 8. Why/how to use styles, applying them automatically,  using the many types of triggers to change styles automatically, using Expression Blend behaviors and templates are all covered. Next chapter, 9, is about graphics and animations programming. It explains how to create shapes, transform common UI elements, apply special effects and perform simple animations. The following chapter, 10, is about creating custom controls, either by deriving from UserControl or from an existing control or framework element class, applying custom templates for changing the way the control looks. One useful example is a custom layout panel that arranges its children along a circumference. The final chapter, 11, is about multi-threading programming and how one can integrate it with WPF. Includes how to invoke methods and properties on WPF classes from threads other than the main UI, using background tasks and timers and even using the new C# 5.0 asynchronous operations. It’s an interesting book, like I said, mostly for newcomers. It provides a competent introduction to WPF, with examples that cover the most common scenarios and also give directions to more complex ones. I recommend it to everyone wishing to learn WPF.

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  • Ubuntu 10.04 & IBM DS3524 with FC multipath, inactive path is [failed][faulty] instead of [active][ghost]

    - by Graeme Donaldson
    OK, this is my setup: FC Switches IBM/Brocade, Switch1 and Switch2, independent fabrics. Server IBM x3650 M2, 2x QLogic QLE2460, 1 connected to each FC Switch. Storage IBM DS3524, 2x controllers with 4x FC ports each, but only 2x connected on each. +-----------------------------------------------------------------------+ | HBA1 Server HBA2 | +-----------------------------------------------------------------------+ | | | | | | +-----------------------------+ +------------------------------+ | Switch1 | | Switch2 | +-----------------------------+ +------------------------------+ | | | | | | | | | | | | | | | | | | | | +-----------------------------------+-----------------------------------+ | Contr A, port 3 | Contr A, port 4 | Contr B, port 3 | Contr B, port 4 | +-----------------------------------+-----------------------------------+ | Storage | +-----------------------------------------------------------------------+ My /etc/multipath.conf is from the IBM redbook for the DS3500, except I use a different setting for prio_callout, IBM uses /sbin/mpath_prio_tpc, but according to http://changelogs.ubuntu.com/changelogs/pool/main/m/multipath-tools/multipath-tools_0.4.8-7ubuntu2/changelog, this was renamed to /sbin/mpath_prio_rdac, which I'm using. devices { device { #ds3500 vendor "IBM" product "1746 FAStT" hardware_handler "1 rdac" path_checker rdac failback 0 path_grouping_policy multibus prio_callout "/sbin/mpath_prio_rdac /dev/%n" } } multipaths { multipath { wwid xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx alias array07 path_grouping_policy multibus path_checker readsector0 path_selector "round-robin 0" failback "5" rr_weight priorities no_path_retry "5" } } The output of multipath -ll with controller A as the preferred path: root@db06:~# multipath -ll sdg: checker msg is "directio checker reports path is down" sdh: checker msg is "directio checker reports path is down" array07 (xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) dm-2 IBM ,1746 FASt [size=4.9T][features=1 queue_if_no_path][hwhandler=0] \_ round-robin 0 [prio=2][active] \_ 5:0:1:0 sdd 8:48 [active][ready] \_ 5:0:2:0 sde 8:64 [active][ready] \_ 6:0:1:0 sdg 8:96 [failed][faulty] \_ 6:0:2:0 sdh 8:112 [failed][faulty] If I change the preferred path using IBM DS Storage Manager to Controller B, the output swaps accordingly: root@db06:~# multipath -ll sdd: checker msg is "directio checker reports path is down" sde: checker msg is "directio checker reports path is down" array07 (xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx) dm-2 IBM ,1746 FASt [size=4.9T][features=1 queue_if_no_path][hwhandler=0] \_ round-robin 0 [prio=2][active] \_ 5:0:1:0 sdd 8:48 [failed][faulty] \_ 5:0:2:0 sde 8:64 [failed][faulty] \_ 6:0:1:0 sdg 8:96 [active][ready] \_ 6:0:2:0 sdh 8:112 [active][ready] According to IBM, the inactive path should be "[active][ghost]", not "[failed][faulty]". Despite this, I don't seem to have any I/O issues, but my syslog is being spammed with this every 5 seconds: Jun 1 15:30:09 db06 multipathd: sdg: directio checker reports path is down Jun 1 15:30:09 db06 kernel: [ 2350.282065] sd 6:0:2:0: [sdh] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE Jun 1 15:30:09 db06 kernel: [ 2350.282071] sd 6:0:2:0: [sdh] Sense Key : Illegal Request [current] Jun 1 15:30:09 db06 kernel: [ 2350.282076] sd 6:0:2:0: [sdh] <<vendor>> ASC=0x94 ASCQ=0x1ASC=0x94 ASCQ=0x1 Jun 1 15:30:09 db06 kernel: [ 2350.282083] sd 6:0:2:0: [sdh] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00 Jun 1 15:30:09 db06 kernel: [ 2350.282092] end_request: I/O error, dev sdh, sector 0 Jun 1 15:30:10 db06 multipathd: sdh: directio checker reports path is down Jun 1 15:30:14 db06 kernel: [ 2355.312270] sd 6:0:1:0: [sdg] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE Jun 1 15:30:14 db06 kernel: [ 2355.312277] sd 6:0:1:0: [sdg] Sense Key : Illegal Request [current] Jun 1 15:30:14 db06 kernel: [ 2355.312282] sd 6:0:1:0: [sdg] <<vendor>> ASC=0x94 ASCQ=0x1ASC=0x94 ASCQ=0x1 Jun 1 15:30:14 db06 kernel: [ 2355.312290] sd 6:0:1:0: [sdg] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00 Jun 1 15:30:14 db06 kernel: [ 2355.312299] end_request: I/O error, dev sdg, sector 0 Does anyone know how I can get the inactive path to show "[active][ghost]" instead of "[failed][faulty]"? I assume that once I can get that right then the spam in my syslog will end as well. One final thing worth mentioning is that the IBM redbook doc targets SLES 11 so I'm assuming there's something a little different under Ubuntu that I just haven't figured out yet. Update: As suggested by Mitch, I've tried removing /etc/multipath.conf, and now the output of multipath -ll looks like this: root@db06:~# multipath -ll sdg: checker msg is "directio checker reports path is down" sdh: checker msg is "directio checker reports path is down" xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxdm-1 IBM ,1746 FASt [size=4.9T][features=0][hwhandler=0] \_ round-robin 0 [prio=1][active] \_ 5:0:2:0 sde 8:64 [active][ready] \_ round-robin 0 [prio=1][enabled] \_ 5:0:1:0 sdd 8:48 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:1:0 sdg 8:96 [failed][faulty] \_ round-robin 0 [prio=0][enabled] \_ 6:0:2:0 sdh 8:112 [failed][faulty] So its more or less the same, with the same message in the syslog every 5 minutes as before, but the grouping has changed.

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  • Silverlight Cream for March 21, 2010 -- #816

    - by Dave Campbell
    In this Issue: Michael Washington, John Papa(-2-, -3-, -4-), Jonas Follesø, David Anson, Scott Guthrie, Andrej Tozon, Bill Reiss(-2-), Pete Blois, and Lee. Shoutouts: Frank LaVigne has a Mix10 Session Downloader for us all to use... thanks Frank! Read what Ward Bell has to say about MVVM, Josh Smith’s Way ... it's all good. Robby Ingebretsen posts on his 10 Favorite Open Source Fonts You Can Embed in WPF or Silverlight Mike Harsh posted Slides and Demos from my MIX10 Session . The download link at Drop.io is down for maintenance until Sunday evening, March 21. From SilverlightCream.com: Blend 4: TreeView SelectedItemChanged using MVVM Michael Washington has a post up about doing SelectedItemChanged on a TreeView with MVVM, oh and he's starting out in Blend 4... Silverlight TV 14: Developing for Windows Phone 7 with Silverlight John Papa hit Silverlight TV pretty hard at the beginning of MIX10. This first one is with Mike Harsh talking about WP7. (Hi Mike ... wondered where you'd run off to!), and you can go to the shoutout section to get Mike's session material from MIX as well. Silverlight TV 15: Announcing Silverlight 4 RC at MIX 10 In this next Silverlight TV(15), John Papa and Adam Kinney discuss Silverlight 4RC ... thank goodness it's out, we can all let go of the breath we've been holding in :) Silverlight TV 16: Tim Heuer and Jesse Liberty Talk about Silverlight 4 RC at MIX 10 Silverlight TV 16 has John Papa sharing the spotlight with Jesse Liberty and Tim Heuer ... geez... can you find 3 more kowledgable Silverlight folks to listen to? No? then go listen to this :) Silverlight TV 17: Build a Twitter Client for Windows Phone 7 with Silverlight The latest Silverlight TV has John Papa bringing Mike Harsh back to produce a Twitter Client for WP7. Simulating multitouch on the Windows Phone 7 Emulator Jonas Follesø has a great post up about simulating multi-touch on WP7 using multiple mice ... yeah, you read that right :) Using IValueConverter to create a grouped list of items simply and flexibly David Anson demonstrates grouping items in a ListBox using IValueConverter. I think I can pretty well guarantee I would NOT have thought of doing this.. :) Building a Windows Phone 7 Twitter Application using Silverlight In the MIX10 first-day keynote, Scott Guthrie did File->New Project and built a WP7 Twitter app. He has that up as a tutorial with all sorts of external links including one to the keynote itself. Named and optional parameters in Silverlight 4 Andrej Tozon delves into the optional parameters that are now available to Silverlight developers... pretty cool stuff. Space Rocks game step 4: Inheriting from Sprite Bill Reiss continues with his game development series with this one on inheriting from the Sprite class and centering objects Space Rocks game step 5: Rotating the ship Bill Reiss's episode 5 is on rotating the ship you setup in episode 4. Don't worry about the transforms, Bill gives it all to us :) Labyrinth Sample for Windows Phone Wow... check out the sample Pete Blois did for the Phone... Silverlight coolness :) PathListBox in SL4 – firstlook Lee has a post up on the PathListBox. I think this is going to catch on quick... it's just too cool not to! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • How do NTP Servers Manage to Stay so Accurate?

    - by Akemi Iwaya
    Many of us have had the occasional problem with our computers and other devices retaining accurate time settings, but a quick sync with an NTP server makes all well again. But if our own devices can lose accuracy, how do NTP servers manage to stay so accurate? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. Photo courtesy of LEOL30 (Flickr). The Question SuperUser reader Frank Thornton wants to know how NTP servers are able to remain so accurate: I have noticed that on my servers and other machines, the clocks always drift so that they have to sync up to remain accurate. How do the NTP server clocks keep from drifting and always remain so accurate? How do the NTP servers manage to remain so accurate? The Answer SuperUser contributor Michael Kjorling has the answer for us: NTP servers rely on highly accurate clocks for precision timekeeping. A common time source for central NTP servers are atomic clocks, or GPS receivers (remember that GPS satellites have atomic clocks onboard). These clocks are defined as accurate since they provide a highly exact time reference. There is nothing magical about GPS or atomic clocks that make them tell you exactly what time it is. Because of how atomic clocks work, they are simply very good at, having once been told what time it is, keeping accurate time (since the second is defined in terms of atomic effects). In fact, it is worth noting that GPS time is distinct from the UTC that we are more used to seeing. These atomic clocks are in turn synchronized against International Atomic Time or TAI in order to not only accurately tell the passage of time, but also the time. Once you have an exact time on one system connected to a network like the Internet, it is a matter of protocol engineering enabling transfer of precise times between hosts over an unreliable network. In this regard a Stratum 2 (or farther from the actual time source) NTP server is no different from your desktop system syncing against a set of NTP servers. By the time you have a few accurate times (as obtained from NTP servers or elsewhere) and know the rate of advancement of your local clock (which is easy to determine), you can calculate your local clock’s drift rate relative to the “believed accurate” passage of time. Once locked in, this value can then be used to continuously adjust the local clock to make it report values very close to the accurate passage of time, even if the local real-time clock itself is highly inaccurate. As long as your local clock is not highly erratic, this should allow keeping accurate time for some time even if your upstream time source becomes unavailable for any reason. Some NTP client implementations (probably most ntpd daemon or system service implementations) do this, and others (like ntpd’s companion ntpdate which simply sets the clock once) do not. This is commonly referred to as a drift file because it persistently stores a measure of clock drift, but strictly speaking it does not have to be stored as a specific file on disk. In NTP, Stratum 0 is by definition an accurate time source. Stratum 1 is a system that uses a Stratum 0 time source as its time source (and is thus slightly less accurate than the Stratum 0 time source). Stratum 2 again is slightly less accurate than Stratum 1 because it is syncing its time against the Stratum 1 source and so on. In practice, this loss of accuracy is so small that it is completely negligible in all but the most extreme of cases. Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

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  • Inside Red Gate - Exercises in Leanness

    - by simonc
    There's a new movement rumbling around Red Gate Towers - the Lean Startup. At its core is the idea that you don't have to be in a company with single-digit employees to be an entrepreneur; you simply have to (being blunt) not know what you should be doing. Specifically, you accept that you don't know everything you need to know in order to create a useful, successful & profitable product. This is something that Red Gate has had problems with in the past; we've created products that weren't aimed at the correct market, or didn't solve the problem the user had (although they solved the problem we thought the users had, or the problem the users thought they had). As a result, these products weren't as successful as they could have been. The ideas at the core of the Lean Startup help to combat this tendency to build large, well-engineered products that solve the wrong problem. You need to actually test your hypotheses about what the users and the market needs, rather than just running a project based on those untested assumptions. Furthermore, these tests need to be done as fast as possible (on the order of a week) so that, if necessary, you can change the direction of the project without wasting effort going down a dead end. Over time, as more tests are done and more hypotheses are confirmed or refuted, the project moves towards something that solves users' actual problems. However, re-aligning the development teams that operate within Red Gate along these lines does itself have some issues; we've got very good at doing large, monolithic releases, with a feature set decided well in advance. Currently it takes about 2 weeks to do install & release testing before a release; this is clearly not practicable for a team doing weekly, or even daily releases. There's also many infrastructure issues to be solved; in our source control, build system, release mechanism, support pages & documentation, licensing system, update system, and download pages. All these need modifications to allow the fast releases necessary for each experiment. Not only do we have to change our infrastructure, we have to change our mindset. Doing daily releases means each release won't get nearly as much testing as 'standard' releases. As a team, we have to be prepared that there will be releases that have bugs and issues with them; not only do we have to be prepared to change direction with every experiment we do, but we have to be ready to fix any bugs that are reported very quickly as well. The SmartAssembly team is spearheading this move towards leanness within the company, using Feature Usage Reporting (FUR). We think this is a cracking feature that will really help developers learn how people use their products, but we need to confirm this hypothesis. So, over the next few weeks, we'll be running a variety of experiments on SmartAssembly to either confirm or refute our hypotheses concerning how people use SmartAssembly and apply FUR to their own products. In the rest of this series, I'll be documenting how the experiments we perform get on, and our experiences with applying the Lean Startup model to a mature product like SmartAssembly. Cross posted from Simple Talk.

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  • Inside Red Gate - Exercises in Leanness

    - by Simon Cooper
    There's a new movement rumbling around Red Gate Towers - the Lean Startup. At its core is the idea that you don't have to be in a company with single-digit employees to be an entrepreneur; you simply have to (being blunt) not know what you should be doing. Specifically, you accept that you don't know everything you need to know in order to create a useful, successful & profitable product. This is something that Red Gate has had problems with in the past; we've created products that weren't aimed at the correct market, or didn't solve the problem the user had (although they solved the problem we thought the users had, or the problem the users thought they had). As a result, these products weren't as successful as they could have been. The ideas at the core of the Lean Startup help to combat this tendency to build large, well-engineered products that solve the wrong problem. You need to actually test your hypotheses about what the users and the market needs, rather than just running a project based on those untested assumptions. Furthermore, these tests need to be done as fast as possible (on the order of a week) so that, if necessary, you can change the direction of the project without wasting effort going down a dead end. Over time, as more tests are done and more hypotheses are confirmed or refuted, the project moves towards something that solves users' actual problems. However, re-aligning the development teams that operate within Red Gate along these lines does itself have some issues; we've got very good at doing large, monolithic releases, with a feature set decided well in advance. Currently it takes about 2 weeks to do install & release testing before a release; this is clearly not practicable for a team doing weekly, or even daily releases. There's also many infrastructure issues to be solved; in our source control, build system, release mechanism, support pages & documentation, licensing system, update system, and download pages. All these need modifications to allow the fast releases necessary for each experiment. Not only do we have to change our infrastructure, we have to change our mindset. Doing daily releases means each release won't get nearly as much testing as 'standard' releases. As a team, we have to be prepared that there will be releases that have bugs and issues with them; not only do we have to be prepared to change direction with every experiment we do, but we have to be ready to fix any bugs that are reported very quickly as well. The SmartAssembly team is spearheading this move towards leanness within the company, using Feature Usage Reporting (FUR). We think this is a cracking feature that will really help developers learn how people use their products, but we need to confirm this hypothesis. So, over the next few weeks, we'll be running a variety of experiments on SmartAssembly to either confirm or refute our hypotheses concerning how people use SmartAssembly and apply FUR to their own products. In the rest of this series, I'll be documenting how the experiments we perform get on, and our experiences with applying the Lean Startup model to a mature product like SmartAssembly.

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  • OWB 11gR2 - Find and Search Metadata in Designer

    - by David Allan
    Here are some tools and techniques for finding objects, specifically in the design repository. There are ways of navigating and collating objects that are useful for day to day development and build-time usage - this includes features out of the box and utilities constructed on top. There are a variety of techniques to navigate and find objects in the repository, the first 3 are out of the box, the 4th is an expert utility. Navigating by the tree, grouping by project and module - ok if you are aware of the exact module/folder that objects reside in. The structure panel is a useful way of finding parts of an object, especially when large rather than using the canvas. In large scale projects it helps to have accelerators (either find or collections below). Advanced find to search by name - 11gR2 included a find capability specifically for large scale projects. There were improvements in both the tree search and the object editors (including highlighting in mapping for example). So you can now do regular expression based search and quickly navigate to objects within a repository. Collections - logically organize your objects into virtual folders by shortcutting the actual objects. This is useful for a range of things since all the OWB services operate on collections too (export/import, validation, deployment). See the post here for new collection functionality in 11gR2. Reports for searching by type, updated on, updated by etc. Useful for activities such as periodic incremental actions (deploy all mappings changed in the past week). The report style view is useful since I can quickly see who changed what and when. You can see all the audit details for objects within each objects property inspector, but its useful to just get all objects changed today or example, all objects changed since my last build etc. This utility combines both UI extensions via experts and the public views on the repository. In the figure to the right you see the contextual option 'Object Search' which invokes the utility, you can see I have quite a number of modules within my project. Figure out all the potential objects which have been changed is not simple. The utility is an expert which provides this kind of search capability. The utility provides a report of the objects in the design repository which satisfy some filter criteria. The type of criteria includes; objects updated in the last n days optionally filter the objects updated by user filter the user by project and by type (table/mappings etc.) The search dialog appears with these options, you can multi-select the object types, so for example you can select TABLE and MAPPING. Its also possible to search across projects if need be. If you have multiple users using the repository you can define the OWB user name in the 'Updated by' property to restrict the report to just that user also. Finally there is a search name that will be used for some of the options such as building a collection - this name is used for the collection to be built. In the example I have done, I've just searched my project for all process flows and mappings that users have updated in the last 7 days. The results of the query are returned in a table containing the object names, types, full path and audit details. The columns are sort-able, you can sort the results by name, type, path etc. One of the cool things here, is that you can then perform operations on these objects - such as edit them, export single selection or entire results to MDL, create a collection from the results (now you have a saved set of references in the repository, you could do deploy/export etc.), create a deployment script from the results...or even add in your own ideas! You see from this that you can do bulk operations on sets of objects based on search results. So for example selecting the 'Build Collection' option creates a collection with all of the objects from my search, you can subsequently deploy/generate/maintain this collection of objects. Under the hood of the expert if just basic OMB commands from the product and the use of the public views on the design repository. You can see how easy it is to build up macro-like capabilities that will help you do day-to-day as well as build like tasks on sets of objects.

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  • Tuple in C# 4.0

    - by Jalpesh P. Vadgama
    C# 4.0 language includes a new feature called Tuple. Tuple provides us a way of grouping elements of different data type. That enables us to use it a lots places at practical world like we can store a coordinates of graphs etc. In C# 4.0 we can create Tuple with Create method. This Create method offer 8 overload like following. So you can group maximum 8 data types with a Tuple. Followings are overloads of a data type. Create(T1)- Which represents a tuple of size 1 Create(T1,T2)- Which represents a tuple of size 2 Create(T1,T2,T3) – Which represents a tuple of size 3 Create(T1,T2,T3,T4) – Which represents a tuple of size 4 Create(T1,T2,T3,T4,T5) – Which represents a tuple of size 5 Create(T1,T2,T3,T4,T5,T6) – Which represents a tuple of size 6 Create(T1,T2,T3,T4,T5,T6,T7) – Which represents a tuple of size 7 Create(T1,T2,T3,T4,T5,T6,T7,T8) – Which represents a tuple of size 8 Following are some example code for tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple); var t = System.Tuple.Create<int, string>(1, "Jalpesh"); Console.WriteLine(t); } } } Following is a output of above as expected. You can also access values insides Tuple with ItemN property. Where N represents particular number of item in tuple. Following is an example of it. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Here you can see I have printed items with Item1,Item2 and Item3 . Following is the output of above code.   Even we can create a nested tuple also following is code for nested tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create(1,"Jalpesh",new Tuple<string,string>("P","Vadgama")); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Following is a output above code as expected. As you can see there are unlimited possibilities we can do lots of things with Tuple. Hope you liked it. Stay tuned for more. Till then Happy Programming!!

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  • How Exactly Is One Linux OS “Based On” Another Linux OS?

    - by Jason Fitzpatrick
    When reviewing different flavors of Linux, you’ll frequently come across phrases like “Ubuntu is based on Debian” but what exactly does that mean? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader PLPiper is trying to get a handle on how Linux variants work: I’ve been looking through quite a number of Linux distros recently to get an idea of what’s around, and one phrase that keeps coming up is that “[this OS] is based on [another OS]“. For example: Fedora is based on Red Hat Ubuntu is based on Debian Linux Mint is based on Ubuntu For someone coming from a Mac environment I understand how “OS X is based on Darwin”, however when I look at Linux Distros, I find myself asking “Aren’t they all based on Linux..?” In this context, what exactly does it mean for one Linux OS to be based on another Linux OS? So, what exactly does it mean when we talk about one version of Linux being based off another version? The Answer SuperUser contributor kostix offers a solid overview of the whole system: Linux is a kernel — a (complex) piece of software which works with the hardware and exports a certain Application Programming Interface (API), and binary conventions on how to precisely use it (Application Binary Interface, ABI) available to the “user-space” applications. Debian, RedHat and others are operating systems — complete software environments which consist of the kernel and a set of user-space programs which make the computer useful as they perform sensible tasks (sending/receiving mail, allowing you to browse the Internet, driving a robot etc). Now each such OS, while providing mostly the same software (there are not so many free mail server programs or Internet browsers or desktop environments, for example) differ in approaches to do this and also in their stated goals and release cycles. Quite typically these OSes are called “distributions”. This is, IMO, a somewhat wrong term stemming from the fact you’re technically able to build all the required software by hand and install it on a target machine, so these OSes distribute the packaged software so you either don’t need to build it (Debian, RedHat) or they facilitate such building (Gentoo). They also usually provide an installer which helps to install the OS onto a target machine. Making and supporting an OS is a very complicated task requiring a complex and intricate infrastructure (upload queues, build servers, a bug tracker, and archive servers, mailing list software etc etc etc) and staff. This obviously raises a high barrier for creating a new, from-scratch OS. For instance, Debian provides ca. 37k packages for some five hardware architectures — go figure how much work is put into supporting this stuff. Still, if someone thinks they need to create a new OS for whatever reason, it may be a good idea to use an existing foundation to build on. And this is exactly where OSes based on other OSes come into existence. For instance, Ubuntu builds upon Debian by just importing most packages from it and repackaging only a small subset of them, plus packaging their own, providing their own artwork, default settings, documentation etc. Note that there are variations to this “based on” thing. For instance, Debian fosters the creation of “pure blends” of itself: distributions which use Debian rather directly, and just add a bunch of packages and other stuff only useful for rather small groups of users such as those working in education or medicine or music industry etc. Another twist is that not all these OSes are based on Linux. For instance, Debian also provide FreeBSD and Hurd kernels. They have quite tiny user groups but anyway. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • SQL SERVER – Basic Calculation and PEMDAS Order of Operation

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

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  • LINQ to Twitter Queries with LINQPad

    - by Joe Mayo
    LINQPad is a popular utility for .NET developers who use LINQ a lot.  In addition to standard SQL queries, LINQPad also supports other types of LINQ providers, including LINQ to Twitter.  The following sections explain how to set up LINQPad for making queries with LINQ to Twitter. LINQPad comes in a couple versions and this example uses LINQPad4, which runs on the .NET Framework 4.0. 1. The first thing you'll need to do is set up a reference to the LinqToTwitter.dll. From the Query menu, select query properties. Click the Browse button and find the LinqToTwitter.dll binary. You should see something similar to the Query Properties window below. 2. While you have the query properties window open, add the namespace for the LINQ to Twitter types.  Click the Additional Namespace Imports tab and type in LinqToTwitter. The results are shown below: 3. The default query type, when you first start LINQPad, is C# Expression, but you'll need to change this to support multiple statements.  Change the Language dropdown, on the Main window, to C# Statements. 4. To query LINQ to Twitter, instantiate a TwitterContext, by typing the following into the LINQPad Query window: var ctx = new TwitterContext(); Note: If you're getting syntax errors, go back and make sure you did steps #2 and #3 properly. 5. Next, add a query, but don't materialize it, like this: var tweets = from tweet in ctx.Status where tweet.Type == StatusType.Public select new { tweet.Text, tweet.Geo, tweet.User }; 6. Next, you want the output to be displayed in the LINQPad grid, so do a Dump, like this: tweets.Dump(); The following image shows the final results:   That was an unauthenticated query, but you can also perform authenticated queries with LINQ to Twitter's support of OAuth.  Here's an example that uses the PinAuthorizer (type this into the LINQPad Query window): var auth = new PinAuthorizer { Credentials = new InMemoryCredentials { ConsumerKey = "", ConsumerSecret = "" }, UseCompression = true, GoToTwitterAuthorization = pageLink => Process.Start(pageLink), GetPin = () => { // this executes after user authorizes, which begins with the call to auth.Authorize() below. Console.WriteLine("\nAfter you authorize this application, Twitter will give you a 7-digit PIN Number.\n"); Console.Write("Enter the PIN number here: "); return Console.ReadLine(); } }; // start the authorization process (launches Twitter authorization page). auth.Authorize(); var ctx = new TwitterContext(auth, "https://api.twitter.com/1/", "https://search.twitter.com/"); var tweets = from tweet in ctx.Status where tweet.Type == StatusType.Public select new { tweet.Text, tweet.Geo, tweet.User }; tweets.Dump(); This code is very similar to what you'll find in the LINQ to Twitter downloadable source code solution, in the LinqToTwitterDemo project.  For obvious reasons, I changed the value assigned to ConsumerKey and ConsumerSecret, which you'll have to obtain by visiting http://dev.twitter.com and registering your application. One tip, you'll probably want to make this easier on yourself by creating your own DLL that encapsulates all of the OAuth logic and then call a method or property on you custom class that returns a fully functioning TwitterContext.  This will help avoid adding all this code every time you want to make a query. Now, you know how to set up LINQPad for LINQ to Twitter, perform unauthenticated queries, and perform queries with OAuth. Joe

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  • Why would Copying a Large Image to the Clipboard Freeze a Computer?

    - by Akemi Iwaya
    Sometimes, something really odd happens when using our computers that makes no sense at all…such as copying a simple image to the clipboard and the computer freezing up because of it. An image is an image, right? Today’s SuperUser post has the answer to a puzzled reader’s dilemna. Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. Original image courtesy of Wikimedia. The Question SuperUser reader Joban Dhillon wants to know why copying an image to the clipboard on his computer freezes it up: I was messing around with some height map images and found this one: (http://upload.wikimedia.org/wikipedia/commons/1/15/Srtm_ramp2.world.21600×10800.jpg) The image is 21,600*10,800 pixels in size. When I right click and select “Copy Image” in my browser (I am using Google Chrome), it slows down my computer until it freezes. After that I must restart. I am curious about why this happens. I presume it is the size of the image, although it is only about 6 MB when saved to my computer. I am also using Windows 8.1 Why would a simple image freeze Joban’s computer up after copying it to the clipboard? The Answer SuperUser contributor Mokubai has the answer for us: “Copy Image” is copying the raw image data, rather than the image file itself, to your clipboard. The raw image data will be 21,600 x 10,800 x 3 (24 bit image) = 699,840,000 bytes of data. That is approximately 700 MB of data your browser is trying to copy to the clipboard. JPEG compresses the raw data using a lossy algorithm and can get pretty good compression. Hence the compressed file is only 6 MB. The reason it makes your computer slow is that it is probably filling your memory up with at least the 700 MB of image data that your browser is using to show you the image, another 700 MB (along with whatever overhead the clipboard incurs) to store it on the clipboard, and a not insignificant amount of processing power to convert the image into a format that can be stored on the clipboard. Chances are that if you have less than 4 GB of physical RAM, then those copies of the image data are forcing your computer to page memory out to the swap file in an attempt to fulfil both memory demands at the same time. This will cause programs and disk access to be sluggish as they use the disk and try to use the data that may have just been paged out. In short: Do not use the clipboard for huge images unless you have a lot of memory and a bit of time to spare. Like pretty graphs? This is what happens when I load that image in Google Chrome, then copy it to the clipboard on my machine with 12 GB of RAM: It starts off at the lower point using 2.8 GB of RAM, loading the image punches it up to 3.6 GB (approximately the 700 MB), then copying it to the clipboard spikes way up there at 6.3 GB of RAM before settling back down at the 4.5-ish you would expect to see for a program and two copies of a rather large image. That is a whopping 3.7 GB of image data being worked on at the peak, which is probably the initial image, a reserved quantity for the clipboard, and perhaps a couple of conversion buffers. That is enough to bring any machine with less than 8 GB of RAM to its knees. Strangely, doing the same thing in Firefox just copies the image file rather than the image data (without the scary memory surge). Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

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  • Project Euler 17: (Iron)Python

    - by Ben Griswold
    In my attempt to learn (Iron)Python out in the open, here’s my solution for Project Euler Problem 17.  As always, any feedback is welcome. # Euler 17 # http://projecteuler.net/index.php?section=problems&id=17 # If the numbers 1 to 5 are written out in words: # one, two, three, four, five, then there are # 3 + 3 + 5 + 4 + 4 = 19 letters used in total. # If all the numbers from 1 to 1000 (one thousand) # inclusive were written out in words, how many letters # would be used? # # NOTE: Do not count spaces or hyphens. For example, 342 # (three hundred and forty-two) contains 23 letters and # 115 (one hundred and fifteen) contains 20 letters. The # use of "and" when writing out numbers is in compliance # with British usage. import time start = time.time() def to_word(n): h = { 1 : "one", 2 : "two", 3 : "three", 4 : "four", 5 : "five", 6 : "six", 7 : "seven", 8 : "eight", 9 : "nine", 10 : "ten", 11 : "eleven", 12 : "twelve", 13 : "thirteen", 14 : "fourteen", 15 : "fifteen", 16 : "sixteen", 17 : "seventeen", 18 : "eighteen", 19 : "nineteen", 20 : "twenty", 30 : "thirty", 40 : "forty", 50 : "fifty", 60 : "sixty", 70 : "seventy", 80 : "eighty", 90 : "ninety", 100 : "hundred", 1000 : "thousand" } word = "" # Reverse the numbers so position (ones, tens, # hundreds,...) can be easily determined a = [int(x) for x in str(n)[::-1]] # Thousands position if (len(a) == 4 and a[3] != 0): # This can only be one thousand based # on the problem/method constraints word = h[a[3]] + " thousand " # Hundreds position if (len(a) >= 3 and a[2] != 0): word += h[a[2]] + " hundred" # Add "and" string if the tens or ones # position is occupied with a non-zero value. # Note: routine is broken up this way for [my] clarity. if (len(a) >= 2 and a[1] != 0): # catch 10 - 99 word += " and" elif len(a) >= 1 and a[0] != 0: # catch 1 - 9 word += " and" # Tens and ones position tens_position_value = 99 if (len(a) >= 2 and a[1] != 0): # Calculate the tens position value per the # first and second element in array # e.g. (8 * 10) + 1 = 81 tens_position_value = int(a[1]) * 10 + a[0] if tens_position_value <= 20: # If the tens position value is 20 or less # there's an entry in the hash. Use it and there's # no need to consider the ones position word += " " + h[tens_position_value] else: # Determine the tens position word by # dividing by 10 first. E.g. 8 * 10 = h[80] # We will pick up the ones position word later in # the next part of the routine word += " " + h[(a[1] * 10)] if (len(a) >= 1 and a[0] != 0 and tens_position_value > 20): # Deal with ones position where tens position is # greater than 20 or we have a single digit number word += " " + h[a[0]] # Trim the empty spaces off both ends of the string return word.replace(" ","") def to_word_length(n): return len(to_word(n)) print sum([to_word_length(i) for i in xrange(1,1001)]) print "Elapsed Time:", (time.time() - start) * 1000, "millisecs" a=raw_input('Press return to continue')

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  • HPCM 11.1.2.2.x - HPCM Standard Costing Generating >99 Calc Scipts

    - by Jane Story
    HPCM Standard Profitability calculation scripts are named based on a documented naming convention. From 11.1.2.2.x, the script name = a script suffix (1 letter) + POV identifier (3 digits) + Stage Order Number (1 digit) + “_” + index (2 digits) (please see documentation for more information (http://docs.oracle.com/cd/E17236_01/epm.1112/hpm_admin/apes01.html). This naming convention results in the name being 8 characters in length i.e. the maximum number of characters permitted calculation script names in non-unicode Essbase BSO databases. The index in the name will indicate the number of scripts per stage. In the vast majority of cases, the number of scripts generated per stage will be significantly less than 100 and therefore, there will be no issue. However, in some cases, the number of scripts generated can exceed 99. It is unusual for an application to generate more than 99 calculation scripts for one stage. This may indicate that explicit assignments are being extensively used. An assessment should be made of the design to see if assignment rules can be used instead. Assignment rules will reduce the need for so many calculation script lines which will reduce the requirement for such a large number of calculation scripts. In cases where the scripts generates exceeds 100, the length of the name of the 100th calculation script is different from the 99th as the calculation script name changes from being 8 characters long and becomes 9 characters long (e.g. A6811_100 rather than A6811_99). A name of 9 characters is not permitted in non Unicode applications. It is “too long”. When this occurs, an error will show in the hpcm.log as “Error processing calculation scripts” and “Unexpected error in business logic “. Further down the log, it is possible to see that this is “Caused by: Error copying object “ and “Caused by: com.essbase.api.base.EssException: Cannot put olap file object ... object name_[<calc script name> e.g. A6811_100] too long for non-unicode mode application”. The error file will give the name of the calculation script which is causing the issue. In my example, this is A6811_100 and you can see this is 9 characters in length. It is not possible to increase the number of characters allowed in a calculation script name. However, it is possible to increase the size of each calculation script. The default for an HPCM application, set in the preferences, is set to 4mb. If the size of each calculation script is larger, the number of scripts generated will reduce and, therefore, less than 100 scripts will be generated which means that the name of the calculation script will remain 8 characters long. To increase the size of the generated calculation scripts for an application, in the HPM_APPLICATION_PREFERENCE table for the application, find the row where HPM_PREFERENCE_NAME_ID=20. The default value in this row is 4194304. This can be increased e.g. 7340032 will increase this to 7mb. Please restart the profitability service after making the change.

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  • Columnstore Case Study #1: MSIT SONAR Aggregations

    - by aspiringgeek
    Preamble This is the first in a series of posts documenting big wins encountered using columnstore indexes in SQL Server 2012 & 2014.  Many of these can be found in this deck along with details such as internals, best practices, caveats, etc.  The purpose of sharing the case studies in this context is to provide an easy-to-consume quick-reference alternative. Why Columnstore? If we’re looking for a subset of columns from one or a few rows, given the right indexes, SQL Server can do a superlative job of providing an answer. If we’re asking a question which by design needs to hit lots of rows—DW, reporting, aggregations, grouping, scans, etc., SQL Server has never had a good mechanism—until columnstore. Columnstore indexes were introduced in SQL Server 2012. However, they're still largely unknown. Some adoption blockers existed; yet columnstore was nonetheless a game changer for many apps.  In SQL Server 2014, potential blockers have been largely removed & they're going to profoundly change the way we interact with our data.  The purpose of this series is to share the performance benefits of columnstore & documenting columnstore is a compelling reason to upgrade to SQL Server 2014. App: MSIT SONAR Aggregations At MSIT, performance & configuration data is captured by SCOM. We archive much of the data in a partitioned data warehouse table in SQL Server 2012 for reporting via an application called SONAR.  By definition, this is a primary use case for columnstore—report queries requiring aggregation over large numbers of rows.  New data is refreshed each night by an automated table partitioning mechanism—a best practices scenario for columnstore. The Win Compared to performance using classic indexing which resulted in the expected query plan selection including partition elimination vs. SQL Server 2012 nonclustered columnstore, query performance increased significantly.  Logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Other than creating the columnstore index, no special modifications or tweaks to the app or databases schema were necessary to achieve the performance improvements.  Existing nonclustered indexes were rendered superfluous & were deleted, thus mitigating maintenance challenges such as defragging as well as conserving disk capacity. Details The table provides the raw data & summarizes the performance deltas. Logical Reads (8K pages) CPU (ms) Durn (ms) Columnstore 160,323 20,360 9,786 Conventional Table & Indexes 9,053,423 549,608 193,903 ? x56 x27 x20 The charts provide additional perspective of this data.  "Conventional vs. Columnstore Metrics" document the raw data.  Note on this linear display the magnitude of the conventional index performance vs. columnstore.  The “Metrics (?)” chart expresses these values as a ratio. Summary For DW, reports, & other BI workloads, columnstore often provides significant performance enhancements relative to conventional indexing.  I have documented here, the first in a series of reports on columnstore implementations, results from an initial implementation at MSIT in which logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Subsequent features in this series document performance enhancements that are even more significant. 

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  • To SYNC or not to SYNC – Part 4

    - by AshishRay
    This is Part 4 of a multi-part blog article where we are discussing various aspects of setting up Data Guard synchronous redo transport (SYNC). In Part 1 of this article, I debunked the myth that Data Guard SYNC is similar to a two-phase commit operation. In Part 2, I discussed the various ways that network latency may or may not impact a Data Guard SYNC configuration. In Part 3, I talked in details regarding why Data Guard SYNC is a good thing, and the distance implications you have to keep in mind. In this final article of the series, I will talk about how you can nicely complement Data Guard SYNC with the ability to failover in seconds. Wait - Did I Say “Seconds”? Did I just say that some customers do Data Guard failover in seconds? Yes, Virginia, there is a Santa Claus. Data Guard has an automatic failover capability, aptly called Fast-Start Failover. Initially available with Oracle Database 10g Release 2 for Data Guard SYNC transport mode (and enhanced in Oracle Database 11g to support Data Guard ASYNC transport mode), this capability, managed by Data Guard Broker, lets your Data Guard configuration automatically failover to a designated standby database. Yes, this means no human intervention is required to do the failover. This process is controlled by a low footprint Data Guard Broker client called Observer, which makes sure that the primary database and the designated standby database are behaving like good kids. If something bad were to happen to the primary database, the Observer, after a configurable threshold period, tells that standby, “Your time has come, you are the chosen one!” The standby dutifully follows the Observer directives by assuming the role of the new primary database. The DBA or the Sys Admin doesn’t need to be involved. And - in case you are following this discussion very closely, and are wondering … “Hmmm … what if the old primary is not really dead, but just network isolated from the Observer or the standby - won’t this lead to a split-brain situation?” The answer is No - It Doesn’t. With respect to why-it-doesn’t, I am sure there are some smart DBAs in the audience who can explain the technical reasons. Otherwise - that will be the material for a future blog post. So - this combination of SYNC and Fast-Start Failover is the nirvana of lights-out, integrated HA and DR, as practiced by some of our advanced customers. They have observed failover times (with no data loss) ranging from single-digit seconds to tens of seconds. With this, they support operations in industry verticals such as manufacturing, retail, telecom, Internet, etc. that have the most demanding availability requirements. One of our leading customers with massive cloud deployment initiatives tells us that they know about server failures only after Data Guard has automatically completed the failover process and the app is back up and running! Needless to mention, Data Guard Broker has the integration hooks for interfaces such as JDBC and OCI, or even for custom apps, to ensure the application gets automatically rerouted to the new primary database after the database level failover completes. Net Net? To sum up this multi-part blog article, Data Guard with SYNC redo transport mode, plus Fast-Start Failover, gives you the ideal triple-combo - that is, it gives you the assurance that for critical outages, you can failover your Oracle databases: very fast without human intervention, and without losing any data. In short, it takes the element of risk out of critical IT operations. It does require you to be more careful with your network and systems planning, but as far as HA is concerned, the benefits outweigh the investment costs. So, this is what we in the MAA Development Team believe in. What do you think? How has your deployment experience been? We look forward to hearing from you!

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  • Why Is Hibernation Still Used?

    - by Jason Fitzpatrick
    With the increased prevalence of fast solid-state hard drives, why do we still have system hibernation? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Moses wants to know why he should use hibernate on a desktop machine: I’ve never quite understood the original purpose of the Hibernation power state in Windows. I understand how it works, what processes take place, and what happens when you boot back up from Hibernate, but I’ve never truly understood why it’s used. With today’s technology, most notably with SSDs, RAM and CPUs becoming faster and faster, a cold boot on a clean/efficient Windows installation can be pretty fast (for some people, mere seconds from pushing the power button). Standby is even faster, sometimes instantaneous. Even SATA drives from 5-6 years ago can accomplish these fast boot times. Hibernation seems pointless to me [on desktop computers] when modern technology is considered, but perhaps there are applications that I’m not considering. What was the original purpose behind hibernation, and why do people still use it? Quite a few people use hibernate, so what is Moses missing in the big picture? The Answer SuperUser contributor Vignesh4304 writes: Normally hibernate mode saves your computer’s memory, this includes for example open documents and running applications, to your hard disk and shuts down the computer, it uses zero power. Once the computer is powered back on, it will resume everything where you left off. You can use this mode if you won’t be using the laptop/desktop for an extended period of time, and you don’t want to close your documents. Simple Usage And Purpose: Save electric power and resuming of documents. In simple terms this comment serves nice e.g (i.e. you will sleep but your memories are still present). Why it’s used: Let me describe one sample scenario. Imagine your battery is low on power in your laptop, and you are working on important projects on your machine. You can switch to hibernate mode – it will result your documents being saved, and when you power on, the actual state of application gets restored. Its main usage is like an emergency shutdown with an auto-resume of your documents. MagicAndre1981 highlights the reason we use hibernate everyday: Because it saves the status of all running programs. I leave all my programs open and can resume working the next day very easily. Doing a real boot would require to start all programs again, load all the same files into those programs, get to the same place that I was at before, and put all my windows in exactly the same place. Hibernating saves a lot of work pulling these things back up again. It’s not unusual to find computers around the office here that have been hibernated day in and day out for months without an actual full system shutdown and restart. It’s enormously convenient to freeze your work space at the exact moment you stopped working and to turn right around and resume there the next morning. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • Feynman's inbox

    - by user12607414
    Here is Richard Feynman writing on the ease of criticizing theories, and the difficulty of forming them: The problem is not just to say something might be wrong, but to replace it by something — and that is not so easy. As soon as any really definite idea is substituted it becomes almost immediately apparent that it does not work. The second difficulty is that there is an infinite number of possibilities of these simple types. It is something like this. You are sitting working very hard, you have worked for a long time trying to open a safe. Then some Joe comes along who knows nothing about what you are doing, except that you are trying to open the safe. He says ‘Why don’t you try the combination 10:20:30?’ Because you are busy, you have tried a lot of things, maybe you have already tried 10:20:30. Maybe you know already that the middle number is 32 not 20. Maybe you know as a matter of fact that it is a five digit combination… So please do not send me any letters trying to tell me how the thing is going to work. I read them — I always read them to make sure that I have not already thought of what is suggested — but it takes too long to answer them, because they are usually in the class ‘try 10:20:30’. (“Seeking New Laws”, page 161 in The Character of Physical Law.) As a sometime designer (and longtime critic) of widely used computer systems, I have seen similar difficulties appear when anyone undertakes to publicly design a piece of software that may be used by many thousands of customers. (I have been on both sides of the fence, of course.) The design possibilities are endless, but the deep design problems are usually hidden beneath a mass of superfluous detail. The sheer numbers can be daunting. Even if only one customer out of a thousand feels a need to express a passionately held idea, it can take a long time to read all the mail. And it is a fact of life that many of those strong suggestions are only weakly supported by reason or evidence. Opinions are plentiful, but substantive research is time-consuming, and hence rare. A related phenomenon commonly seen with software is bike-shedding, where interlocutors focus on surface details like naming and syntax… or (come to think of it) like lock combinations. On the other hand, software is easier than quantum physics, and the population of people able to make substantial suggestions about software systems is several orders of magnitude bigger than Feynman’s circle of colleagues. My own work would be poorer without contributions — sometimes unsolicited, sometimes passionately urged on me — from the open source community. If a Nobel prize winner thought it was worthwhile to read his mail on the faint chance of learning a good idea, I am certainly not going to throw mine away. (In case anyone is still reading this, and is wondering what provoked a meditation on the quality of one’s inbox contents, I’ll simply point out that the volume has been very high, for many months, on the Lambda-Dev mailing list, where the next version of the Java language is being discussed. Bravo to those of my colleagues who are surfing that wave.) I started this note thinking there was an odd parallel between the life of the physicist and that of a software designer. On second thought, I’ll bet that is the story for anybody who works in public on something requiring special training. (And that would be pretty much anything worth doing.) In any case, Feynman saw it clearly and said it well.

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  • Fetching Partition Information

    - by Mike Femenella
    For a recent SSIS package at work I needed to determine the distinct values in a partition, the number of rows in each partition and the file group name on which each partition resided in order to come up with a grouping mechanism. Of course sys.partitions comes to mind for some of that but there are a few other tables you need to link to in order to grab the information required. The table I’m working on contains 8.8 billion rows. Finding the distinct partition keys from this table was not a fast operation. My original solution was to create  a temporary table, grab the distinct values for the partitioned column, then update via sys.partitions for the rows and the $partition function for the partitionid and finally look back to the sys.filegroups table for the filegroup names. It wasn’t pretty, it could take up to 15 minutes to return the results. The primary issue is pulling distinct values from the table. Queries for distinct against 8.8 billion rows don’t go quickly. A few beers into a conversation with a friend and we ended up talking about work which led to a conversation about the task described above. The solution was already built in SQL Server, just needed to pull it together. The first table I needed was sys.partition_range_values. This contains one row for each range boundary value for a partition function. In my case I have a partition function which uses dayid values. For example July 4th would be represented as an int, 20130704. This table lists out all of the dayid values which were defined in the function. This eliminated the need to query my source table for distinct dayid values, everything I needed was already built in here for me. The only caveat was that in my SSIS package I needed to create a bucket for any dayid values that were out of bounds for my function. For example if my function handled 20130501 through 20130704 and I had day values of 20130401 or 20130705 in my table, these would not be listed in sys.partition_range_values. I just created an “everything else” bucket in my ssis package just in case I had any dayid values unaccounted for. To get the number of rows for a partition is very easy. The sys.partitions table contains values for each partition. Easy enough to achieve by querying for the object_id and index value of 1 (the clustered index) The final piece of information was the filegroup name. There are 2 options available to get the filegroup name, sys.data_spaces or sys.filegroups. For my query I chose sys.filegroups but really it’s a matter of preference and data needs. In order to bridge between sys.partitions table and either sys.data_spaces or sys.filegroups you need to get the container_id. This can be done by joining sys.allocation_units.container_id to the sys.partitions.hobt_id. sys.allocation_units contains the field data_space_id which then lets you join in either sys.data_spaces or sys.file_groups. The end result is the query below, which typically executes for me in under 1 second. I’ve included the join to sys.filegroups and to sys.dataspaces, and I’ve  just commented out the join sys.filegroups. As I mentioned above, this shaves a good 10-15 minutes off of my original ssis package and is a really easy tweak to get a boost in my ETL time. Enjoy.

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  • Columnstore Case Study #1: MSIT SONAR Aggregations

    - by aspiringgeek
    Preamble This is the first in a series of posts documenting big wins encountered using columnstore indexes in SQL Server 2012 & 2014.  Many of these can be found in this deck along with details such as internals, best practices, caveats, etc.  The purpose of sharing the case studies in this context is to provide an easy-to-consume quick-reference alternative. Why Columnstore? If we’re looking for a subset of columns from one or a few rows, given the right indexes, SQL Server can do a superlative job of providing an answer. If we’re asking a question which by design needs to hit lots of rows—DW, reporting, aggregations, grouping, scans, etc., SQL Server has never had a good mechanism—until columnstore. Columnstore indexes were introduced in SQL Server 2012. However, they're still largely unknown. Some adoption blockers existed; yet columnstore was nonetheless a game changer for many apps.  In SQL Server 2014, potential blockers have been largely removed & they're going to profoundly change the way we interact with our data.  The purpose of this series is to share the performance benefits of columnstore & documenting columnstore is a compelling reason to upgrade to SQL Server 2014. App: MSIT SONAR Aggregations At MSIT, performance & configuration data is captured by SCOM. We archive much of the data in a partitioned data warehouse table in SQL Server 2012 for reporting via an application called SONAR.  By definition, this is a primary use case for columnstore—report queries requiring aggregation over large numbers of rows.  New data is refreshed each night by an automated table partitioning mechanism—a best practices scenario for columnstore. The Win Compared to performance using classic indexing which resulted in the expected query plan selection including partition elimination vs. SQL Server 2012 nonclustered columnstore, query performance increased significantly.  Logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Other than creating the columnstore index, no special modifications or tweaks to the app or databases schema were necessary to achieve the performance improvements.  Existing nonclustered indexes were rendered superfluous & were deleted, thus mitigating maintenance challenges such as defragging as well as conserving disk capacity. Details The table provides the raw data & summarizes the performance deltas. Logical Reads (8K pages) CPU (ms) Durn (ms) Columnstore 160,323 20,360 9,786 Conventional Table & Indexes 9,053,423 549,608 193,903 ? x56 x27 x20 The charts provide additional perspective of this data.  "Conventional vs. Columnstore Metrics" document the raw data.  Note on this linear display the magnitude of the conventional index performance vs. columnstore.  The “Metrics (?)” chart expresses these values as a ratio. Summary For DW, reports, & other BI workloads, columnstore often provides significant performance enhancements relative to conventional indexing.  I have documented here, the first in a series of reports on columnstore implementations, results from an initial implementation at MSIT in which logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Subsequent features in this series document performance enhancements that are even more significant. 

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  • Can you/should you develop components for ASP.NET MVC?

    - by Vilx-
    Following from the previous question I've started to wonder - is it possible to implement "Components" in ASP.NET MVC (latest version)? And should you? Let's clarify what I mean with a "component". With that I mean a "control" (aka "widget"), similar to those that ASP.NET webforms is built upon. A gridview might be a good example. In webforms I can place on my form a datasource component (one line of code), a gridview component (another line of code) and bind them together (specify an attribute on the gridview). In the codebehind file I fill the datasource with data (a few lines of DB-querying code), and I'm all set. At this point the gridview is a fully functional standalone component. I can open the form, and I'll see all the data. I can sort it by clicking on the column headers; it is split into several pages; I can drag the column headers around and rearrange columns; I can turn on "grouping" mode; etc. And I don't need to write another line of code for any of it. The gridview, as a component, already has all the code tucked away in its classes and assemblies. I just place it on the form, initialize it, and it Just Works. At some times (like sorting or navigation to a different page) it will also perform ajax callbacks to the server, but those too will be handled internally, with my code having no knowledge at all about it. And then there are also events that I can attach if I want to get notified when something happens. In MVC I cannot see a way of doing this cleanly. Sure, there are the partial views, but those only handle half of the problem - they render the initial HTML. Some more can be achieved with client-side Javascript (like column re-arranging), but when the grid needs to do an ajax callback (say, to fetch the next page of data), my code will have to get involved and process that request. At best I guess I can provide some helper methods to process it, but I'll have to write the code that calls them, and also provide a controller method with signature matching the arguments of that callback. I guess that I could make some hacks with global events or special routes or something, but that just seems... hackish. Unelegant. Perhaps this is not the MVC way? Although I've completed one project in it, I'm still far from being an MVC expert. But then what is? In the intranet application that we're building there are dozens upon dozens of such grids. Naturally I want them all to have a unified look & behavior, and I don't want to repeat the same code all over the place. So what's the "MVC" approach to this problem?

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