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• Is it possible to cache all the data in a SQL Server CE database using LinqToSql?

  - by DanM

  I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

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• Build OpenGL model in parallel?

  - by Brendan Long

  I have a program which draws some terrain and simulates water flowing over it (in a cheap and easy way). Updating the water was easy to parallelize using OpenMP, so I can do ~50 updates per second. The problem is that even with a small amounts of water, my draws per second are very very low (starts at 5 and drops to around 2 once there's a significant amount of water). It's not a problem with the video card because the terrain is more complicated and gets drawn so quickly that boost::timer tells me that I get infinity draws per second if I turn the water off. It may be related to memory bandwidth though (since I assume the model stays on the card and doesn't have to be transfered every time). What I'm concerned about is that on every draw, I'm calling glVertex3f() about a million times (max size is 450*600, 4 vertices each), and it's done entirely sequentially because Glut won't let me call anything in parallel. So.. is if there's some way of building the list in parallel and then passing it to OpenGL all at once? Or some other way of making it draw this faster? Am I using the wrong method (besides the obvious "use less vertices")?

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• Syntax errors on Heroku, but not on local server (postgresql related?)

  - by Phil_Ken_Sebben

  I'm trying to deploy my first app on Heroku (rails 3). It works fine on my local server, but when I pushed it to Heroku and ran it, it crashes, giving a number of syntax errors. These are related to a collection of scopes I use like the one below: scope :scored, lambda { |score = nil| score.nil? ? {} : where('products.votes_count >= ?', score) } it produces errors of this form: "syntax error, unexpected '=', expecting '|' " "syntax error, unexpected '}', expecting kEND" Why is this syntax making Heroku choke and how can I correct it? Thanks! EDIT: I was using sqlite on my local machine and Heroku does not support that. Trying to make sure the db is properly configured for PG. I believe I have done that by specifying in the gemfile that sqlite only be used in development. Yet I still get these syntax errors, that interrupt even the db:migrate. EDIT: So now it seems more likely that my scope syntax doesn't work in postgreSQL. Does anyone know how to convert this properly?

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• STI and accepts_nested_attributes_for in rails

  - by ryanshackintosh

  I have models as follows: class Entity < ActiveRecord::Base has_many :addresses accepts_nested_attributes_for :addresses, :reject_if => lambda { |a| a[:label].blank?} , :allow_destroy => true end class Client < Entity before_save :set_type private def set_type self.type = "Client" end end class Address < ActiveRecord::Base belongs_to :entity end I have recently implemented accepts_nested_attributes_for on the /clients/new form, as follows: <% form_for(@client, :html => {:class => 'form'}) do |f| -%> <%= f.label :name %> <%= f.text_field :name -%> <%= f.label :phone %> <%= f.text_field :phone %> <% f.fields_for :addresses do |a| %> <%= a.label :street %> <%= a.text_field :street%> <%= a.label :city %> <%= a.text_field :city %> <% end %> <% end %> And my controller as follows: class ClientsController < ApplicationController before_filter :load_client , :except => [:index, :new, :create, :render_clients] def new @client = Client.new @client.addresses.build end def create @client = Client.new(params[:client]) if @client.save flash[:notice] = 'Client has been successfully added' redirect_to @client else render :action => 'new' end end The issue is that when the record is saved it gives an error stating: "Entity can't be blank" I assume it is something to do with the fact that a 'Client' and not an 'Entity' is being added. Can anyone point me in the right direction?

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• C Population Count of unsigned 64-bit integer with a maximum value of 15

  - by BitTwiddler1011

  I use a population count (hamming weight) function intensively in a windows c application and have to optimize it as much as possible in order to boost performance. More than half the cases where I use the function I only need to know the value to a maximum of 15. The software will run on a wide range of processors, both old and new. I already make use of the POPCNT instruction when Intel's SSE4.2 or AMD's SSE4a is present, but would like to optimize the software implementation (used as a fall back if no SSE4 is present) as much as possible. Currently I have the following software implementation of the function: inline int population_count64(unsigned __int64 w) { w -= (w 1) & 0x5555555555555555ULL; w = (w & 0x3333333333333333ULL) + ((w 2) & 0x3333333333333333ULL); w = (w + (w 4)) & 0x0f0f0f0f0f0f0f0fULL; return int(w * 0x0101010101010101ULL) 56; } So to summarize: (1) I would like to know if it is possible to optimize this for the case when I only want to know the value to a maximum of 15. (2) Is there a faster software implementation (for both Intel and AMD CPU's) than the function above?

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• Making Extension method Generic

  - by Ian

  In this post there's a very interesting way of updating UI threads using a static extension method. public static void InvokeIfRequired(this Control c, Action<Control> action) { if(c.InvokeRequired) { c.Invoke(() => action(c)); } else { action(c); } } What I want to do, is to make a generic version, so I'm not constrained by a control. This would allow me to do the following for example (because I'm no longer constrained to just being a Control) this.progressBar1.InvokeIfRequired(pb => pb.Value = e.Progress); I've tried the following: public static void InvokeIfRequired<T>(this T c, Action<T> action) where T : Control { if (c.InvokeRequired) { c.Invoke(() => action(c)); } else { action(c); } } But I get the following error that I'm not sure how to fix. Anyone any suggestions? Error 5 Cannot convert lambda expression to type 'System.Delegate' because it is not a delegate type

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• What to throw in a C++ class wrapping a C library ?

  - by ereOn

  I have to create a set of wrapping C++ classes around an existing C library. For many objects of the C library, the construction is done by calling something like britney_spears* create_britney_spears() and the opposite function void free_britney_spears(britney_spears* brit). If the allocation of a britney_spears fails, create_britney_spears() returns NULL. This is, as far as I know, a very common pattern. Now I want to wrap this inside a C++ class. //britney_spears.hpp class BritneySpears { public: BritneySpears(); private: boost::shared_ptr<britney_spears> m_britney_spears; }; And here is the implementation: // britney_spears.cpp BritneySpears::BritneySpears() : m_britney_spears(create_britney_spears(), free_britney_spears) { if (!m_britney_spears) { // Here I should throw something to abort the construction, but what ??! } } So the question is in the code sample: What should I throw to abort the constructor ? I know I can throw almost anything, but I want to know what is usually done. I have no other information about why the allocation failed. Should I create my own exception class ? Is there a std exception for such cases ? Many thanks.

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• Effective simulation of compound poisson process in Matlab

  - by Henrik

  I need to simulate a huge bunch of compound poisson processes in Matlab on a very fine grid so I am looking to do it most effectively. I need to do a lot of simulations on the same random numbers but with parameters changing so it is practical to draw the uniforms and normals beforehand even though it means i have to draw a lot more than i will probably need and won't matter much because it will only need to be done once compared to in the order 500*n repl times the actual compound process generation. My method is the following: Let T be for how long i need to simulate and N the grid points, then my grid is: t=linspace(1,T,N); Let nrepl be the number of processes i need then I simulate P=poissrnd(lambda,nrepl,1); % Number of jumps for each replication U=(T-1)*rand(10000,nrepl)+1; % Set of uniforms on (1,T) for jump times N=randn(10000,nrepl); % Set of normals for jump size Then for replication j: Poiss=P(j); % Jumps for replication Uni=U(1:Poiss,j);% Jump times Norm=mu+sigma*N(1:Poiss,j);% Jump sizes Then this I guess is where I need your advice, I use this one-liner but it seems very slow: CPP_norm=sum(bsxfun(@times,bsxfun(@gt,t,Uni),Norm),1); In the inner for each jump it creates a series of same length as t with 0 until jump and then 1 after, multiplying this will create a grid with zeroes until jump has arrived and then the jump size and finally adding all these will produce the entire jump process on the grid. How can this be done more effectively? Thank you very much.

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• how to pass vector of string to foo(char const *const *const)?

  - by user347208

  Hi, This is my first post so please be nice. I searched in this forum and googled but I still can not find the answer. This problem has bothered me for more than a day, so please give me some help. Thank you. I need to pass a vector of string to a library function foo(char const *const *const). I can not pass the &Vec[0] since it's a pointer to a string. Therefore, I have an array and pass the c_str() to that array. The following is my code (aNames is the vector of string): const char* aR[aNames.size()]; std::transform(aNames.begin(), aNames.end(), aR, boost::bind(&std::string::c_str, _1)); foo(aR); However, it seems it causes some undefined behavior: If I run the above code, then the function foo throw some warnings about illegal characters ('èI' blablabla) in aR. If I print aR before function foo like this: std::copy(aR, aR+rowNames.size(), std::ostream_iterator<const char*>(std::cout, "\n")); foo(aR); Then, everything is fine. My questions are: Does the conversion causes undefined behavior? If so, why? What is the correct way to pass vector of string to foo(char const *const *const)? Thank you very much for your help!

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• php / phpDoc - @return instance of $this class ?

  - by searbe

  How do I mark a method as "returns an instance of the current class" in my phpDoc? In the following example my IDE (Netbeans) will see that setSomething always returns a foo object. But that's not true if I extent the object - it'll return $this, which in the second example is a bar object not a foo object. class foo { protected $_value = null; /** * Set something * * @param string $value the value * @return foo */ public function setSomething($value) { $this->_value = $value; return $this; } } $foo = new foo(); $out = $foo->setSomething(); So fine - setSomething returns a foo - but in the following example, it returns a bar..: class bar extends foo { public function someOtherMethod(){} } $bar = new bar(); $out = $bar->setSomething(); $out->someOtherMethod(); // <-- Here, Netbeans will think $out // is a foo, so doesn't see this other // method in $out's code-completion ... it'd be great to solve this as for me, code completion is a massive speed-boost. Anyone got a clever trick, or even better, a proper way to document this with phpDoc?

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• Dynamic programming Approach- Knapsack Puzzle

  - by idalsin

  I'm trying to solve the Knapsack problem with the dynamical programming(DP) approach, with Python 3.x. My TA pointed us towards this code for a head start. I've tried to implement it, as below: def take_input(infile): f_open = open(infile, 'r') lines = [] for line in f_open: lines.append(line.strip()) f_open.close() return lines def create_list(jewel_lines): #turns the jewels into a list of lists jewels_list = [] for x in jewel_lines: weight = x.split()[0] value = x.split()[1] jewels_list.append((int(value), int(weight))) jewels_list = sorted(jewels_list, key = lambda x : (-x[0], x[1])) return jewels_list def dynamic_grab(items, max_weight): table = [[0 for weight in range(max_weight+1)] for j in range(len(items)+1)] for j in range(1,len(items)+1): val= items[j-1][0] wt= items[j-1][1] for weight in range(1, max_weight+1): if wt > weight: table[j][weight] = table[j-1][weight] else: table[j][weight] = max(table[j-1][weight],table[j-1][weight-wt] + val) result = [] weight = max_weight for j in range(len(items),0,-1): was_added = table[j][weight] != table[j-1][weight] if was_added: val = items[j-1][0] wt = items[j-1][1] result.append(items[j-1]) weight -= wt return result def totalvalue(comb): #total of a combo of items totwt = totval = 0 for val, wt in comb: totwt += wt totval += val return (totval, -totwt) if totwt <= max_weight else (0,0) #required setup of variables infile = "JT_test1.txt" given_input = take_input(infile) max_weight = int(given_input[0]) given_input.pop(0) jewels_list = create_list(given_input) #test lines print(jewels_list) print(greedy_grab(jewels_list, max_weight)) bagged = dynamic_grab(jewels_list, max_weight) print(totalvalue(bagged)) The sample case is below. It is in the format line[0] = bag_max, line[1:] is in form(weight, value): 575 125 3000 50 100 500 6000 25 30 I'm confused as to the logic of this code in that it returns me a tuple and I'm not sure what the output tuple represents. I've been looking at this for a while and just don't understand what the code is pointing me at. Any help would be appreciated.

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• C++0x Smart Pointer Comparisons: Inconsistent, what's the rationale?

  - by GManNickG

  In C++0x (n3126), smart pointers can be compared, both relationally and for equality. However, the way this is done seems inconsistent to me. For example, shared_ptr defines operator< be equivalent to: template <typename T, typename U> bool operator<(const shared_ptr<T>& a, const shared_ptr<T>& b) { return std::less<void*>()(a.get(), b.get()); } Using std::less provides total ordering with respect to pointer values, unlike a vanilla relational pointer comparison, which is unspecified. However, unique_ptr defines the same operator as: template <typename T1, typename D1, typename T2, typename D2> bool operator<(const unique_ptr<T1, D1>& a, const unique_ptr<T2, D2>& b) { return a.get() < b.get(); } It also defined the other relational operators in similar fashion. Why the change in method and "completeness"? That is, why does shared_ptr use std::less while unique_ptr uses the built-in operator<? And why doesn't shared_ptr also provide the other relational operators, like unique_ptr? I can understand the rationale behind either choice: with respect to method: it represents a pointer so just use the built-in pointer operators, versus it needs to be usable within an associative container so provide total ordering (like a vanilla pointer would get with the default std::less predicate template argument) with respect to completeness: it represents a pointer so provide all the same comparisons as a pointer, versus it is a class type and only needs to be less-than comparable to be used in an associative container, so only provide that requirement But I don't see why the choice changes depending on the smart pointer type. What am I missing? Bonus/related: std::shared_ptr seems to have followed from boost::shared_ptr, and the latter omits the other relational operators "by design" (and so std::shared_ptr does too). Why is this?

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• [c++/STL] Selective iterator

  - by rubenvb

  FYI: no boost, yes it has this, I want to reinvent the wheel ;) Is there some form of a selective iterator (possible) in C++? What I want is to seperate strings like this: some:word{or other to a form like this: some : word { or other I can do that with two loops and find_first_of(":") and ("{") but this seems (very) inefficient to me. I thought that maybe there would be a way to create/define/write an iterator that would iterate over all these values with for_each. I fear this will have me writing a full-fledged custom way-too-complex iterator class for a std::string. So I thought maybe this would do: std::vector<size_t> list; size_t index = mystring.find(":"); while( index != std::string::npos ) { list.push_back(index); index = mystring.find(":", list.back()); } std::for_each(list.begin(), list.end(), addSpaces(mystring)); This looks messy to me, and I'm quite sure a more elegant way of doing this exists. But I can't think of it. Anyone have a bright idea? Thanks PS: I did not test the code posted, just a quick write-up of what I would try

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• Can someone explain RAID-0 in plain English?

  - by Edward Tanguay

  I've heard about and read about RAID throughout the years and understand it theoretically as a way to help e.g. server PCs reduce the chance of data loss, but now I am buying a new PC which I want to be as fast as possible and have learned that having two drives can considerably increase the perceived performance of your machine. In the question Recommendations for hard drive performance boost, the author says he is going to RAID-0 two 7200 RPM drives together. What does this mean in practical terms for me with Windows 7 installed, e.g. can I buy two drives, go into the device manager and "raid-0 them together"? I am not a network administrator or a hardware guy, I'm just a developer who is going to have a computer store build me a super fast machine next week. I can read the wikipedia page on RAID but it is just way too many trees and not enough forest to help me build a faster PC: RAID-0: "Striped set without parity" or "Striping". Provides improved performance and additional storage but no redundancy or fault tolerance. Because there is no redundancy, this level is not actually a Redundant Array of Inexpensive Disks, i.e. not true RAID. However, because of the similarities to RAID (especially the need for a controller to distribute data across multiple disks), simple strip sets are normally referred to as RAID 0. Any disk failure destroys the array, which has greater consequences with more disks in the array (at a minimum, catastrophic data loss is twice as severe compared to single drives without RAID). A single disk failure destroys the entire array because when data is written to a RAID 0 drive, the data is broken into fragments. The number of fragments is dictated by the number of disks in the array. The fragments are written to their respective disks simultaneously on the same sector. This allows smaller sections of the entire chunk of data to be read off the drive in parallel, increasing bandwidth. RAID 0 does not implement error checking so any error is unrecoverable. More disks in the array means higher bandwidth, but greater risk of data loss. So in plain English, how can "RAID-0" help me build a faster Windows-7 PC that I am going to order next week?

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• Sysadmin 101: How can I figure out why my server crashes and monitor performance?

  - by bflora

  I have a Drupal-powered site that seems to have neverending performance problems. It was butt-slow about 5 months ago. I brought in some guys who installed nginx for anonymous visitors, ajaxified a few queries so they wouldn't fire during page load, and helped me find a few bottlenecks in the code. For about a month, the site was significantly faster, though not "fast" by any stretch of the word. Meanwhile, I'm now shelling out $400/month to Slicehost to host a site that gets less than 5,000/uniques a day. Yes, you read that right. Go Drupal. Recently the site started crashing again and is slow again. I can't afford to hire people to come in, study my code from top to bottom, and make changes that may or may not help anymore. And I can't afford to throw more hardware at the problem. So I need to figure out what the problem is myself. Questions: When apache crashes, is it possible to find out what caused it to crash? There has to be a way, right? If so, how can I do this? Is there software I can use that will tell me which process caused my server to die? (e.g. "Apache crashed because someone visited page X." or "Apache crashed because you were importing too many RSS items from feed X.") There's got to be a way to learn this, right? What's a good, noob-friendly way to monitor my current apache performance? My developer friends tell me to "just use Top, dude," but Top shows me a bunch of numbers without any context. I have no clue what qualifies as a bad number or a good number in Top, or which processes are relevant and which aren't. Are there any noob-friendly server monitoring tools out there? Ideally, I could have a page that would give me a color-coded indicator about how apache is performing and then show me a list of processes or pages that are sucking right now. This way, I could know when performance is bad and then what's causing it to be so bad. Why does PHP memory matter? My apparently has a 30MB memory foot print. Will it run faster if I bring that number down? Thanks for any advice. I spent a year or so trying to boost my advertising income so I could hire a contractor to solve my performance woes. I didn't want to have to learn all this sysadmin voodoo. I'm now resigned to the fact that might not have a choice.

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• Crashes and freezes after fixing "BOOTMGR is missing" error

  - by Greg-J

  I came back from a 3-day weekend to a computer that was off. I leave my PC on 24/7, so this was odd. Turn it on to get the dreaded "BOOTMGR is missing" screen. Two attempts at Windows Recovery and it booted into Windows fine. After an hour or so, I get a frozen Chrome and my start bar disappears. Ctrl+Alt+Del brings up an error box telling me that Ctrl+Alt+Del failed to work properly. Clicking on any open application triggers an error (I can't recall the error now, but it essentially just said that the application couldn't be found running or something along those lines). I restart, and again, the same thing happens after a while of use. I turn it on, install the 47 updates I have or so, and then restart it. After a while of use (under an hour), it just freezes completely. My thoughts are: SSDs, RAM or PS. My system specs below: (RAID0) 2 x Crucial M4 CT128M4SSD2 2.5" 128GB SATA III MLC Internal Solid State Drive (SSD) CORSAIR Vengeance 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CML16GX3M4A1600C9 CORSAIR HX Series HX750 750W ATX12V 2.3 / EPS12V 2.91 SLI Ready CrossFire Ready 80 PLUS GOLD Certified Modular Active 1 x ASUS Maximus IV Gene-Z/GEN3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard 1 x Hitachi GST Deskstar 7K1000.C 0F10383 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive 1 x Intel Core i7-2600K Sandy Bridge 3.4GHz (3.8GHz Turbo Boost) LGA 1155 95W Quad-Core Desktop Processor Intel HD Graphics 1 x SAPPHIRE 21197-00-40G Radeon HD 7970 3GB 384-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card 1 x Noctua NH-D14 120mm & 140mm SSO CPU Cooler This is all crammed in a pretty small case (NZXT Vulcan) and has been running perfectly problem-free since January. The only thing out of the ordinary is that there is a fan in the case that is now making noise whereas the case has previously been completely silent. I have no reason to believe this is anything more then correlation, but felt it is worth mentioning. I believe it MAY be the SSDs simply because of the BOOTMGR error, but not sure how to test that theory. My belief that it may be the RAM is simply from experience with frozen machines. I haven't had the time to memtest it, but will. The PS being the culprit is something I've picked up by reading similar threads on various forums, and it seems plausible. I am unsure how to test this though. ANY insight whatsover would be greatly appreciated!

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• How can I verify that my SSD is performing as it should?

  - by Jon Skeet

  EDIT: Okay, so I've no idea what caused the change, but after trying loads of different things to work out what was wrong, I've rerun the WEI (about the 4th time in total) and the score has jumped to a far more respectable 7.3. I'm going to leave well alone now :) I've got a brand new 256GB SSD (Crucial CT256M225) which should have stellar performance. However, on my (also brand new) Dell Studio 1557 with Windows 7 Professional 64 bit, it's only giving a performance index of 5.9. I realise the performance index should be taken with a bit of a pinch of salt, but I wonder whether something's wrong. Given this paragraph from this MSDN article on Windows 7, I'd expect to see a high 6.X or possible a 7.X figure: In Windows 7, there are new random read, random write and flush assessments. Better SSDs can score above 6.5 all the way to 7.9. To be included in that range, an SSD has to have outstanding random read rates and be resilient to flush and random write workloads. In the Beta timeframe of Windows 7, there was a capping of scores at 1.9, 2.9 or the like if a disk (SSD or HDD) didn’t perform adequately when confronted with our random write and flush assessments. Feedback on this was pretty consistent, with most feeling the level of capping to be excessive. As a result, we now simply restrict SSDs with performance issues from joining the newly added 6.0+ and 7.0+ ranges. SSDs that are not solid performers across all assessments effectively get scored in a manner similar to what they would have been in Windows Vista, gaining no Win7 boost for great random read performance. How can I diagnose any performance issues with either the disk or how Windows 7 is handling it? Are there any particularly good tools you'd recommend? One note of curiosity: I couldn't install the firmware update (to 1916) until I changed my BIOS handling of the drive to ATA mode; after installing the firmware I tried to boot the Windows installation DVD - but that only worked after turning it back to AHCI mode (which I've left it in). Installing Windows 7 took longer than I expected - it sat at the "Windows is loading files" prompt for a very long time. Likewise it was on "Expanding files (0%)" for a long time. Since installation it's been fine though - but I don't know whether it's really providing quite as beefy performance as it should. EDIT: My netbook with the 64GB equivalent drive has a performance index of 6.6...

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• How do i return integers from a string ?

  - by kannan.ambadi

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Suppose you are passing a string(for e.g.: “My name has 1 K, 2 A and 3 N”)  which may contain integers, letters or special characters. I want to retrieve only numbers from the input string. We can implement it in many ways such as splitting the string into an array or by using TryParse method. I would like to share another idea, that’s by using Regular expressions. All you have to do is, create an instance of Regular Expression with a specified pattern for integer. Regular expression class defines a method called Split, which splits the specified input string based on the pattern provided during object initialization.     We can write the code as given below:   public static int[] SplitIdSeqenceValues(object combinedArgs)         {             var _argsSeperator = new Regex(@"\D+", RegexOptions.Compiled);               string[] splitedIntegers = _argsSeperator.Split(combinedArgs.ToString());               var args = new int[splitedIntegers.Length];               for (int i = 0; i < splitedIntegers.Length; i++)                 args[i] = MakeSafe.ToSafeInt32(splitedIntegers[i]);                           return args;         }    It would be better, if we set to RegexOptions.Compiled so that the regular expression will have performance boost by faster compilation.   Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Happy Programming  :))   

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• Developer’s Life – Summary of Superhero Articles

  - by Pinal Dave

  Earlier this year, I wrote an article series where I talked about developer’s life and compared it with Superhero. I have got amazing response to this series and I have been receiving quite a lots of email suggesting that I should write more blog post about them. Currently I am not planning to write more blog post but I will soon continue another series. In this blog post, I have summarized the entire series. Let me know if you want me to write about any superhero. I will see what I can do about that hero. Developer’s Life – Every Developer is a Captain America Captain America was first created as a comic book character in the 1940’s as a way to boost morale during World War II.  Aimed at a children’s audience, his legacy faded away when the war ended.  However, he has recently has a major reboot to become a popular movie character that deals with modern issues. Developer’s Life – Every Developer is the Incredible Hulk The Incredible Hulk is possibly one of the scariest superheroes out there.  All superheroes are meant to be “out of this world” and awe-inspiring, but I think most people will agree with I say The Hulk takes this to the next level.  He is the result of an industrial accident, which is scary enough in it’s own right.  Plus, when mild-mannered Bruce Banner is angered, he goes completely out-of-control and transforms into a destructive monster that he cannot control and has no memories of. Developer’s Life – Every Developer is a Wonder Woman We have focused a lot lately on this “superhero series.”  I love fantasy books and movies, and I feel like there is a lot to be learned from them.  As I am writing this series, though, I have noticed that every super hero I write about is a man.  So today, I would like to talk about the major female super hero – Wonder Woman. Developer’s Life – Every Developer is a Harry Potter Harry Potter might not be a superhero in the traditional sense, but I believe he still has a lot to teach us and show us about life as a developer.  If you have been living under a rock for the last 17 years, you might not know that Harry Potter is the main character in an extremely popular series of books and movies documenting the education and tribulation of a young wizard (and his friends). Developer’s Life – Every Developer is Like Transformers Transformers may not be superheroes – they don’t wear capes, they don’t have amazing powers outside of their size and folding ability, they’re not even human (technically).  Part of their enduring popularity is that while we are enjoying over-the-top movies, we are learning about good leadership and strong personal skills. Developer’s Life – Every Developer is a Iron Man Iron Man is another superhero who is not naturally “super,” but relies on his brain (and money) to turn him into a fighting machine.  While traditional superheroes are still popular, a three-movie franchise and incorporation into the new Avengers series shows that Iron Man is popular enough on his own. Developer’s Life – Every Developer is a Sherlock Holmes I have been thinking a lot about how developers are like super heroes, and I have written two blog posts now comparing them to Spiderman and Superman.  I have a lot of love and respect for developers, and I hope that they are enjoying these articles, and others are learning a little bit about the profession.  There is another fictional character who, while not technically asuper hero, is very powerful, and I also think stands as a good example of a developer. That character is Sherlock Holmes.  Sherlock Holmes is a British detective, first made popular at the turn of the 19thcentury by author Sir Arthur Conan Doyle.  The original Sherlock Holmes was a brilliant detective who could solve the most mind-boggling crime through simple observations and deduction. Developer’s Life – Every Developer is a Chhota Bheem Chhota Bheem is a cartoon character that is extremely popular where I live.  He is my daughter’s favorite characters.  I like to say that children love Chhota Bheem more than their parents – it is lucky for us he is not real!  Children love Chhota Bheem because he is the absolute “good guy.”  He is smart, loyal, and strong.  He and his friends live in Dholakpur and fight off their many enemies – and always win – in every episode.  In each episode, they learn something about friendship, bravery, and being kind to others.  Chhota Bheem is a good role model for children, and I think that he is a good role model for developers are well. Developer’s Life – Every Developer is a Batman Batman is one of the darkest superheroes in the fantasy canon.  He does not come to his powers through any sort of magical coincidence or radioactive insect, but through a lot of psychological scarring caused by witnessing the death of his parents.  Despite his dark back story, he possesses a lot of admirable abilities that I feel bear comparison to developers. Developer’s Life – Every Developer is a Superman I enjoyed comparing developers to Spiderman so much, that I have decided to continue the trend and encourage some of my favorite people (developers) with another favorite superhero – Superman.  Superman is probably the most famous superhero – and one of the most inspiring. Developer’s Life – Every Developer is a Spiderman I have to admit, Spiderman is my favorite superhero.  The most recent movie recently was released in theaters, so it has been at the front of my mind for some time. Spiderman was my favorite superhero even before the latest movie came out, but of course I took my whole family to see the movie as soon as I could!  Every one of us loved it, including my daughter.  We all left the movie thinking how great it would be to be Spiderman.  So, with that in mind, I started thinking about how we are like Spiderman in our everyday lives, especially developers. I would like to know which Superhero is your favorite hero! Reference: Pinal Dave (http://blog.SQLAuthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Developer, Superhero

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• Commercial Drupal Modules & Themes

  - by Ravish

  A discussion at Drupal.org forums prompted me to give my input about commercial ecosystem around Open Source Content Management Systems. WordPress and Joomla have been growing rapidly since past few years. But, growth rate of Drupal seems to be almost flat. Despite being the most powerful CMS around, Drupal is still not being adopted by masses. Many people will argue that Drupal is not targeted towards masses, but developers. I agree, Drupal is more of a development platform than a consumer CMS. Drupal is ‘many things to many people’, and I can build almost any type of website with it. Drupal is being used for building blogs, corporate websites, Intranet portals, social networking and even a project management system. Looking at the wide array of Drupal implementations, it deserves to be the most widely adopted CMS. I believe there are few challenges that Drupal community needs to overcome. To understand these challenges, I surveyed some webmasters who use Joomla or WordPress but not Drupal. I asked them why they don’t want to use Drupal, following are the responses I got from them: Drupal is too complicated, takes time to learn. Drupal is great, but its admin panel is overwhelming. I couldn’t find any nice themes for Drupal. There is no WYSIWYG editor in Drupal. Most Drupal modules do not work out of the box. There aren’t enough modules like Ubercart which provides any out of the box functionality. I tried modules like CCK, Views and Panels. After wasting several hours struggling with them, I decided to give up on Drupal. I don’t use Drupal because of pushbutton and Garland theme. I had hard time trying to customize Garland and it messed up the whole layout. There are no premium modules and themes for Drupal. Joomla has tons of awesome themes and modules. I don’t want a million hacks like CCK, Views, Tokens, Pathauto, ImageCache and CTools just to run a simple website. Most of the complaints from users are related to the learning and development curve involved with Drupal, and the lack of ecosystem. While most of the problems will be gone in Drupal 7, ecosystem is something that needs to be built by the Drupal community. Drupal distributions are a great step forward. There are few awesome Drupal distributions available like Open Publish, Open Atrium and Drupal Commons. I predict, there will be a wave of many powerful Drupal distributions after Drupal 7 release. Many of them will be user-friendly and commercial supported. Following is my post at Drupal.org forums: Quote from: http://drupal.org/node/863776#comment-3313836 Brian Gardner (StudioPress) and Woo Themes launched premium WordPress themes in 2007, the developer community did not accept it at first. Moreover, they were not even GPL licensed. There was an outcry in WordPress community against them. Following that, most premium theme providers switched to GPL licensing. Despite controversies, users voted for premium theme and plugins by buying them. Inspired by their success, hundreds of other developers started to sell premium themes and plugins. It is now the acceptable and in fact most popular business model among WordPress community. Matt Mullenweg once told me, they would not support premium themes. If he supported, developers would no more give out free GPL themes & plugins. He pointed me towards Joomla, there were hardly any nice free themes & modules available. Now two years forward, premium products are not just accepted but embraced by the WordPress community – http://wordpress.org/extend/themes/commercial/ The quality and number of themes & modules has increased, even the free ones. This also helped to boost the adoption and ecosystem of WordPress. Today, state of Drupal is like WordPress was in 2007. There are hardly any out of the box solutions available for Drupal. Ubercart, Open Publish and Open Atrium are the only ones I can think of. Many of the popular Drupal modules are patches and hole-fillers. Thankfully, these hole-filler modules are going to be in Drupal 7 core. Drupal 7 and distributions will spawn a new array of solutions built upon Drupal. Soon, we will have more like Ubercarts and Open Atriums. If commercial solutions can help fuel this ecosystem and growth, Drupal community will accept them eventually. This debate will not stop your customers from buying your product. If your product is awesome, they will vote for you by buying your product.

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• Information Indepth Newsletter - Linux Edition

  - by Paulo Folgado

  INFORMATION INDEPTH NEWSLETTERLinux Edition February 2011 Stay Connected:  NEWS Now Available: Oracle Linux 6 Get the latest release of Oracle Linux 6, which includes Unbreakable Enterprise Kernel.Download Oracle Linux 6 Read More Customers Succeed by Using Oracle Exadata with Oracle Linux Watch IT executives from Bank of America, Linkshare, and Johns Hopkins as they talk about the business challenges they faced and why they chose to use Oracle Linux along with Oracle Exadata as the solution. Watch Now Video Interview: Oracle Senior Vice President Wim Coekaerts Watch Wim Coekaerts, senior vice president, Linux and Virtualization Engineering, as he talks about use cases for Oracle VM Templates as well as the Unbreakable Enterprise Kernel for Linux.Watch Now Hot Off the Press: Migrate Your IBM AIX Environment to Oracle Linux This new white paper provides recommendations for planning and implementing the migration of applications from an IBM Power System running AIX to Oracle's Sun Fire X4800 Server with Intel Xeon 7560 Processor running Oracle Linux 5.5.Read More  Back to Top BLOGOSPHERE Just Launched: The Oracle Linux Blog Follow our new Oracle Linux blog  to hear the latest updates, product news, upcoming events, and all the latest happenings, directly from the Linux team at Oracle. Back to Top TECH DIVE NEW: Linux/Oracle Solaris CommandComparo Site from Oracle Technology NetworkThis site gives equivalent command syntax in Oracle Solaris 10 and Oracle Enterprise Linux 5 for common administrative tasks--focusing particularly on tasks that have tricky syntax or that you frequently need to double check. It acts as a quick reference for administrators who operate in these two OS environments. Free Download: Oracle Linux Release 5.6Did you know that by using Oracle Linux 5.5 or 5.6 along with the Unbreakable Enterprise Kernel, you can get all the benefits of Linux mainline kernel 2.6.32 and more, right now, without the need to reinstall or migrate to a new operating system such as RHEL6?Read Release NotesDownload Oracle Linux 5.6 LSB 4.0 Certification Completed for Oracle Linux 5.5Oracle Linux 5.5 with Unbreakable Enterprise Kernel successfully completed the LSB 4.0 certification.  Back to Top WEBCASTS Boost Your Linux Performance with Oracle's Enhancements in Infiniband and RDSRegister to hear Director of Kernel Engineering Chris Mason cover scalability and performance improvements in Linux environment. Get the Facts Oracle's Unbreakable Enterprise KernelSVP Wim Coekaerts and Senior Director Monica Kumar cover the facts about and benefits of using Unbreakable Enterprise Kernel.  View Other Webcasts on Demand   Back to Top EVENTS Collaborate 2011April 10-14 Orlando, Florida Cloud Summit Events, WorldwideVarious dates (check the city for date/time of event) Datacenter Efficiency Events WorldwideThese events include Linux and Oracle VM sessions.Various dates (check the city for date/time of event) Virtualization Events in North America Find an Oracle Event  Back to Top EDUCATION Get Oracle Linux Certified from Oracle University Oracle University offers courses in both Oracle Linux and the administration of Oracle Database on Linux.  Back to Top CUSTOMER SPOTLIGHT Pella Corporation Improves IT Performance and Efficiency with Oracle Linux and Oracle VM To improve IT performance and efficiency and lower operational costs, Pella Corporation, has standardized on Oracle VM and Oracle Linux. Read More Disney Store Deploys POS in 330 Stores and 7 Countries on Oracle Linux Disney Store is running 1,500 registers worldwide on a broad Oracle technology software stack including Oracle Database 11g, Oracle Fusion Middleware, and Oracle Linux. Read More Back to Top PARTNER SPOTLIGHT Emulex and Oracle Announce Data Integrity Features The Unbreakable Enterprise Kernel provides data integrity checking between Oracle Database applications and Emulex 8Gb/s LightPulse Fibre Channel Host Bus Adapters. Read More Dell Inc. Dell Inc. tested and validated configurations support Oracle Linux. Back to Top STAY IN TOUCH Follow @ORCL_Linux on Twitter for the latest penguin tweets Bookmark Oracle.com/Linux Read the Oracle Linux blog Back to Top  Oracle Information InDepth newsletters bring targeted news, articles, customer stories, and special offers to business people who want to find out how to streamline enterprise information management, measure results, improve business processes, and communicate a single truth to their constituents. Please send questions or comments to [email protected]. For answers to questions about subscribing, unsubscribing, and managing your Oracle e-mail communications preferences, please see the Oracle E-Mail Communications page. Copyright © 2011, Oracle Corporation and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor is it subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. 

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• Parallelism in .NET – Part 17, Think Continuations, not Callbacks

  - by Reed

  In traditional asynchronous programming, we’d often use a callback to handle notification of a background task’s completion.  The Task class in the Task Parallel Library introduces a cleaner alternative to the traditional callback: continuation tasks. Asynchronous programming methods typically required callback functions.  For example, MSDN’s Asynchronous Delegates Programming Sample shows a class that factorizes a number.  The original method in the example has the following signature: public static bool Factorize(int number, ref int primefactor1, ref int primefactor2) { //... .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } However, calling this is quite “tricky”, even if we modernize the sample to use lambda expressions via C# 3.0.  Normally, we could call this method like so: int primeFactor1 = 0; int primeFactor2 = 0; bool answer = Factorize(10298312, ref primeFactor1, ref primeFactor2); Console.WriteLine("{0}/{1} [Succeeded {2}]", primeFactor1, primeFactor2, answer); If we want to make this operation run in the background, and report to the console via a callback, things get tricker.  First, we need a delegate definition: public delegate bool AsyncFactorCaller( int number, ref int primefactor1, ref int primefactor2); Then we need to use BeginInvoke to run this method asynchronously: int primeFactor1 = 0; int primeFactor2 = 0; AsyncFactorCaller caller = new AsyncFactorCaller(Factorize); caller.BeginInvoke(10298312, ref primeFactor1, ref primeFactor2, result => { int factor1 = 0; int factor2 = 0; bool answer = caller.EndInvoke(ref factor1, ref factor2, result); Console.WriteLine("{0}/{1} [Succeeded {2}]", factor1, factor2, answer); }, null); This works, but is quite difficult to understand from a conceptual standpoint.  To combat this, the framework added the Event-based Asynchronous Pattern, but it isn’t much easier to understand or author. Using .NET 4’s new Task<T> class and a continuation, we can dramatically simplify the implementation of the above code, as well as make it much more understandable.  We do this via the Task.ContinueWith method.  This method will schedule a new Task upon completion of the original task, and provide the original Task (including its Result if it’s a Task<T>) as an argument.  Using Task, we can eliminate the delegate, and rewrite this code like so: var background = Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }); background.ContinueWith(task => Console.WriteLine("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result)); This is much simpler to understand, in my opinion.  Here, we’re explicitly asking to start a new task, then continue the task with a resulting task.  In our case, our method used ref parameters (this was from the MSDN Sample), so there is a little bit of extra boiler plate involved, but the code is at least easy to understand. That being said, this isn’t dramatically shorter when compared with our C# 3 port of the MSDN code above.  However, if we were to extend our requirements a bit, we can start to see more advantages to the Task based approach.  For example, supposed we need to report the results in a user interface control instead of reporting it to the Console.  This would be a common operation, but now, we have to think about marshaling our calls back to the user interface.  This is probably going to require calling Control.Invoke or Dispatcher.Invoke within our callback, forcing us to specify a delegate within the delegate.  The maintainability and ease of understanding drops.  However, just as a standard Task can be created with a TaskScheduler that uses the UI synchronization context, so too can we continue a task with a specific context.  There are Task.ContinueWith method overloads which allow you to provide a TaskScheduler.  This means you can schedule the continuation to run on the UI thread, by simply doing: Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }).ContinueWith(task => textBox1.Text = string.Format("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result), TaskScheduler.FromCurrentSynchronizationContext()); This is far more understandable than the alternative.  By using Task.ContinueWith in conjunction with TaskScheduler.FromCurrentSynchronizationContext(), we get a simple way to push any work onto a background thread, and update the user interface on the proper UI thread.  This technique works with Windows Presentation Foundation as well as Windows Forms, with no change in methodology.

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• SQL SERVER – CXPACKET – Parallelism – Usual Solution – Wait Type – Day 6 of 28

  - by pinaldave

  CXPACKET has to be most popular one of all wait stats. I have commonly seen this wait stat as one of the top 5 wait stats in most of the systems with more than one CPU. Books On-Line: Occurs when trying to synchronize the query processor exchange iterator. You may consider lowering the degree of parallelism if contention on this wait type becomes a problem. CXPACKET Explanation: When a parallel operation is created for SQL Query, there are multiple threads for a single query. Each query deals with a different set of the data (or rows). Due to some reasons, one or more of the threads lag behind, creating the CXPACKET Wait Stat. There is an organizer/coordinator thread (thread 0), which takes waits for all the threads to complete and gathers result together to present on the client’s side. The organizer thread has to wait for the all the threads to finish before it can move ahead. The Wait by this organizer thread for slow threads to complete is called CXPACKET wait. Note that not all the CXPACKET wait types are bad. You might experience a case when it totally makes sense. There might also be cases when this is unavoidable. If you remove this particular wait type for any query, then that query may run slower because the parallel operations are disabled for the query. Reducing CXPACKET wait: We cannot discuss about reducing the CXPACKET wait without talking about the server workload type. OLTP: On Pure OLTP system, where the transactions are smaller and queries are not long but very quick usually, set the “Maximum Degree of Parallelism” to 1 (one). This way it makes sure that the query never goes for parallelism and does not incur more engine overhead. EXEC sys.sp_configure N'cost threshold for parallelism', N'1' GO RECONFIGURE WITH OVERRIDE GO Data-warehousing / Reporting server: As queries will be running for long time, it is advised to set the “Maximum Degree of Parallelism” to 0 (zero). This way most of the queries will utilize the parallel processor, and long running queries get a boost in their performance due to multiple processors. EXEC sys.sp_configure N'cost threshold for parallelism', N'0' GO RECONFIGURE WITH OVERRIDE GO Mixed System (OLTP & OLAP): Here is the challenge. The right balance has to be found. I have taken a very simple approach. I set the “Maximum Degree of Parallelism” to 2, which means the query still uses parallelism but only on 2 CPUs. However, I keep the “Cost Threshold for Parallelism” very high. This way, not all the queries will qualify for parallelism but only the query with higher cost will go for parallelism. I have found this to work best for a system that has OLTP queries and also where the reporting server is set up. Here, I am setting ‘Cost Threshold for Parallelism’ to 25 values (which is just for illustration); you can choose any value, and you can find it out by experimenting with the system only. In the following script, I am setting the ‘Max Degree of Parallelism’ to 2, which indicates that the query that will have a higher cost (here, more than 25) will qualify for parallel query to run on 2 CPUs. This implies that regardless of the number of CPUs, the query will select any two CPUs to execute itself. EXEC sys.sp_configure N'cost threshold for parallelism', N'25' GO EXEC sys.sp_configure N'max degree of parallelism', N'2' GO RECONFIGURE WITH OVERRIDE GO Read all the post in the Wait Types and Queue series. Additionally a must read comment of Jonathan Kehayias. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest you all to read the online book for further clarification. All the discussion of Wait Stats over here is generic and it varies from system to system. It is recommended that you test this on the development server before implementing on the production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• Optimizing collision engine bottleneck

  - by Vittorio Romeo

  Foreword: I'm aware that optimizing this bottleneck is not a necessity - the engine is already very fast. I, however, for fun and educational purposes, would love to find a way to make the engine even faster. I'm creating a general-purpose C++ 2D collision detection/response engine, with an emphasis on flexibility and speed. Here's a very basic diagram of its architecture: Basically, the main class is World, which owns (manages memory) of a ResolverBase*, a SpatialBase* and a vector<Body*>. SpatialBase is a pure virtual class which deals with broad-phase collision detection. ResolverBase is a pure virtual class which deals with collision resolution. The bodies communicate to the World::SpatialBase* with SpatialInfo objects, owned by the bodies themselves. There currenly is one spatial class: Grid : SpatialBase, which is a basic fixed 2D grid. It has it's own info class, GridInfo : SpatialInfo. Here's how its architecture looks: The Grid class owns a 2D array of Cell*. The Cell class contains two collection of (not owned) Body*: a vector<Body*> which contains all the bodies that are in the cell, and a map<int, vector<Body*>> which contains all the bodies that are in the cell, divided in groups. Bodies, in fact, have a groupId int that is used for collision groups. GridInfo objects also contain non-owning pointers to the cells the body is in. As I previously said, the engine is based on groups. Body::getGroups() returns a vector<int> of all the groups the body is part of. Body::getGroupsToCheck() returns a vector<int> of all the groups the body has to check collision against. Bodies can occupy more than a single cell. GridInfo always stores non-owning pointers to the occupied cells. After the bodies move, collision detection happens. We assume that all bodies are axis-aligned bounding boxes. How broad-phase collision detection works: Part 1: spatial info update For each Body body: Top-leftmost occupied cell and bottom-rightmost occupied cells are calculated. If they differ from the previous cells, body.gridInfo.cells is cleared, and filled with all the cells the body occupies (2D for loop from the top-leftmost cell to the bottom-rightmost cell). body is now guaranteed to know what cells it occupies. For a performance boost, it stores a pointer to every map<int, vector<Body*>> of every cell it occupies where the int is a group of body->getGroupsToCheck(). These pointers get stored in gridInfo->queries, which is simply a vector<map<int, vector<Body*>>*>. body is now guaranteed to have a pointer to every vector<Body*> of bodies of groups it needs to check collision against. These pointers are stored in gridInfo->queries. Part 2: actual collision checks For each Body body: body clears and fills a vector<Body*> bodiesToCheck, which contains all the bodies it needs to check against. Duplicates are avoided (bodies can belong to more than one group) by checking if bodiesToCheck already contains the body we're trying to add. const vector<Body*>& GridInfo::getBodiesToCheck() { bodiesToCheck.clear(); for(const auto& q : queries) for(const auto& b : *q) if(!contains(bodiesToCheck, b)) bodiesToCheck.push_back(b); return bodiesToCheck; } The GridInfo::getBodiesToCheck() method IS THE BOTTLENECK. The bodiesToCheck vector must be filled for every body update because bodies could have moved meanwhile. It also needs to prevent duplicate collision checks. The contains function simply checks if the vector already contains a body with std::find. Collision is checked and resolved for every body in bodiesToCheck. That's it. So, I've been trying to optimize this broad-phase collision detection for quite a while now. Every time I try something else than the current architecture/setup, something doesn't go as planned or I make assumption about the simulation that later are proven to be false. My question is: how can I optimize the broad-phase of my collision engine maintaining the grouped bodies approach? Is there some kind of magic C++ optimization that can be applied here? Can the architecture be redesigned in order to allow for more performance? Actual implementation: SSVSCollsion Body.h, Body.cpp World.h, World.cpp Grid.h, Grid.cpp Cell.h, Cell.cpp GridInfo.h, GridInfo.cpp

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• OpenWorld: Spotlight on Fusion CRM

  - by Tony Berk

  Oracle OpenWorld is less than 2 weeks away, so you need to start figuring out how you are going to maximize your week. I don't want to discourage you, but I'm pretty sure it is impossible to attend all 2000+ sessions. So you need to focus on what's important to you. Many of our CRM customers will be interested in Fusion CRM, since they have already started Fusion implementations or determining when to start. If that's you, or you are just looking for an overview of Fusion CRM, we've got you covered! Let's start at the top! For an overview of what is in Fusion CRM and where it is going, you should attend the general session and roadmap session: General Session: Oracle Fusion CRM—Improving Sales Effectiveness, Efficiency, and Ease of Use (Session ID: GEN9674) - Oct 2, 11:45 AM. Anthony Lye, Senior VP, Oracle leads this general session focused on Oracle Fusion CRM. Oracle Fusion CRM optimizes territories, combines quota management and incentive compensation, integrates sales and marketing, and cleanses and enriches data—all within a single application platform. Oracle Fusion can be configured, changed, and extended at runtime by end users, business managers, IT, and developers. Oracle Fusion CRM can be used from the Web, from a smartphone, from Microsoft Outlook, or from an iPad. Deloitte, sponsor of the CRM Track, will also present key concepts on CRM implementations. Oracle Fusion Customer Relationship Management: Overview/Strategy/Customer Experiences/Roadmap (CON9407) - Oct 1, 3:15PM. In this session, learn how Oracle Fusion CRM enables companies to create better sales plans, generate more quality leads, and achieve higher win rates and find out why customers are adopting Oracle Fusion CRM. Gain a deeper understanding of the unique capabilities only Oracle Fusion CRM provides, and learn how Oracle’s commitment to CRM innovation is driving a wide range of future enhancements. There is also a General Session for all Fusion Applications providing insight into the current strategy of the full product line and a high-level roadmap for each product area: Oracle Fusion Applications—Overview, Strategy, and Roadmap (GEN9433) - Oct 1, 10:45AM. This session will be repeated on Oct 3, 10:15AM. Now, if you want to drill down into some more detail, there are a lot more sessions with Oracle product management and customers. I'll highlight a few, but suggest you review the Fusion CRM Focus On document, or the search in the Content Catalog or Session Builder.  Driving Sales Performance with Oracle Fusion CRM (CON9744) - Oct 3, 10:15AM. Demonstrates how sales executives can gain instant visibility into their business, deliver pervasive coaching to their reps, maximize their sales pipeline, and drive team alignment. The result is increased sales performance that enables sales executives to deliver more revenue without increasing their resources or expenses. Maximize Your Revenue Potential with Oracle Fusion CRM Sales Planning (CON9751) - Oct 2, 1:15PM. Learn how Oracle Fusion CRM helps companies intelligently optimize sales planning and manage sales performance including the ability to predict their future sales opportunities and use those predictions in conjunction with past sales data to optimally define their sales territories, sales quotas, and incentive compensation plans. Boost Marketing’s Contribution to Revenue with Oracle Fusion CRM Marketing (CON9746) - Oct 3, 11:45AM. Learn how Oracle Fusion CRM can help your organization integrate sales and marketing, using one CRM platform. See how Oracle Fusion CRM can help your organization learn where to invest its precious marketing dollars; drive more revenue with cross-channel marketing and prospecting capabilities, including and not limited to e-mail, Web, and social media; improve lead conversion with integrated lead management functionality; and do more with less by automating many manual tasks. Oracle Fusion CRM: Social Marketing (CON11559) - Oct 1, 3:15PM. Learn how Oracle’s acquisition of Collective Intellect, Vitrue, and Involver extends Oracle Fusion Marketing as a world-class social marketing solution. Oracle Fusion Social CRM Strategy and Roadmap: Future of Collaboration and Social Engagement (CON9750) - Oct 4, 11:15AM. Hear how Oracle can help you know your customers better, encourage brand affinity, and improve collaboration within your ecosystem. This session reviews Oracle's social media solution and shows how you can discover hidden insights buried in your enterprise and social data. Also learn how Oracle Social Network revolutionizes how enterprise users work, collaborate, and share to achieve successful outcomes. Of course, we recommend you hear from the current Fusion CRM customers too. So, don't miss Oracle Fusion Customer Relationship Management: Customer Adoption and Experiences (CON9415) on Oct 3 at 10:15AM for panel of customers discussing implementation experiences, best practices and benefits.  After listening to all of this great information, you are probably going to have questions. Well, the experts will be on hand to help answer your questions and plan how your organization can get going with Fusion CRM. Be sure to head down to the DEMOgrounds and CRM Pavilion in the Moscone West Exhibit Hall. And finally, there is the always popular Meet the Experts session focused on Fusion CRM (MTE9658) on Oct 2 at 5PM (pre-registration via Schedule Builder is recommended.) In addition, there are more sessions on Mobility, Extensibility, Incentive Compensation, Fusion Customer Hub and other key components of the Fusion Applications infrastructure, Oracle Cloud and much, much more! For a full list, utilize the Fusion CRM Focus On document and Content Catalog. Enjoy!

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