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  • Server Configuration / Important Parameter for 500Req/Second

    - by Sparsh Gupta
    I am configuring a server to be used as nginx server for a very heavy traffic website. It is expected to receive traffic from a large number of IP addresses simultaneously. It is expected to get 500Req/Second with atleast 20Million unique IPs connecting it. One of the problems I noticed in my previos server was related to iptables / ipconntrack. I am not aware of this behaviour and would be glad to know which all parameters of a ubuntu / debian (32/64) bit machine should I tweek to get maximum performance from the server. I can put in a lot of RAM on the server but mission critical task is the response times. We ideally dont want any connection to be hanging / timing out / waiting and want as low as possible overall response times. P.S. We are also looking for a kick ass freelancer system admin who can help us figuring / setting this all up. Reach me incase you have some spare time and interested in working on some very heavy traffic website servers.

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  • PostgreSQL server: 10k RPM SAS or Intel 520 Series SSD drives?

    - by Vlad
    We will be expanding the storage for a PostgreSQL server and one of the things we are considering is using SSDs (Intel 520 Series) instead of rotating discs (10k RPM). Price per GB is comparable and we expect improved performance, however we are concerned about longevity since our database usage pattern is quite write-heavy. We are also concerned about data corruption in case of power failure (due to SSDs write cache not flushing properly). We currently use RAID10 with 4 active HDDs (10k 146GB) and 1 spare configured in the controller. It's a HP DL380 G6 server with P410 Smart Array Controller and BBWC. What makes more sense: upgrading the drives to 300GB 10k RPM or using Intel 520 Series SSDs (240GB)?

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  • Clone remote CentOS server to local test server?

    - by dannymcc
    We have a dedicated server running ContOS 5.5. The server runs our Magento store and a basic php website with mysql. I have a spare rack server in my office (HP ProLiant DL360 G4) that has more than enough storage space to store a duplicate of our dedicated server. I would like to clone the dedicated server entirely and have a local duplicate. It wouldn't need to be kept in sync because I can do that with GIT. The reason I want to do this is simple; learn more about the dedicated server and CentOS. Is this possible? I have SSH access to the dedicated server and obviously complete access to the local server.

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  • How share internet connection between two laptops

    - by danielgratzz
    I have what appears to be a cable modem plugged into the wall with only ONE ethernet port on it. Therefore i can only connect one computer to it. Also, it has no wireless capability. I have to dialup the connection and enter a username and password on my laptop. But how can i share this internet connection between two laptops running windows 7 ultimate? I have spare ethernet cables if that would help... Please help, thank You.

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  • Possible to restore Windows Partition disk image?

    - by kd7iwp
    I have a machine that was dual-booting Windows 7 and Ubuntu 12.04. I used the Disks program in Ubuntu to make a disk image of my windows partition which I saved on an external disk. I then reformatted the main drive and installed Ubuntu 12.10. I created a spare partition and restored that Windows disk image to that partition. Is it possible to boot Windows? I have run boot-repair and Grub now gives me both Ubuntu and Windows options but when I select Windows I get only a black screen with blinking cursor. I ran a Windows recovery disk and ran startup repair but still no luck. I also tried running lilo inside Ubuntu but still can't boot Windows. Any other ideas? PS, I'm on a Netbook with no DVD drive so I can't just reinstall Windows though if that is my only option I can borrow a DVD eventually.

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  • Port forwarding no longer works

    - by Auryn
    Prior to testing an OpenVPN installation, I setup a basic VPN server using the software already built into Windows 7. Port forwarding on the Linksys router worked as normal and I was able to connect remotely. After doing an install of OpenVPN Access Server on a spare box running Ubuntu, and adding new ports to be forwarded I was unable to access the VPN from an external source as the required ports all indicated that they were closed. (During testing XRDP and VNCSERVER were also installed to facilitate access to the box) Checking back on the Windows 7 VPN resulted in no access to that vpn setup either. All ports are now reporting a being closed despite being previously open even ports that were being used for other services. Adding and removing port forwarding rules seem to have no effect. At this point, in order to troubleshoot, both the firewall and anti-virus software have been disabled on the Windows 7 machine. Could this be just a router issue? Is there any way out of this without having to reset and reconfigure the router?

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  • Unlocking AMD Phenom II X2 550 Black Edition cores - what are the risks?

    - by Vilx-
    I've got the above mentioned CPU and a GigaByte GA-MA790XT-UD4P motherboard, which should be capable of unlocking the extra two cores - if I'm lucky and they're not faulty. The Internet is full of instructions on how to do that. What I don't have is spare money to buy new hardware if I brick something. What are the risks when attempting to do this? Is it completely safe, or can I be left with an expensive pile of junk? What should I keep in mind when doing so? Bigger cooler maybe (I'm running with the default box cooler)? Should I lower the frequencies too? I've never done any OC before.

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  • Call for authors for new eBook on the Windows Azure Platform

    - by Eric Nelson
    I intend to pull together a FREE eBook on the Windows Azure Platform – but I need your help to make it rock! If you have detailed experience of any aspect of the Windows Azure Platform and can spare a few hours of time to turn that into a short article (400 to 800 words) then please get in touch. This is not a big commitment but my suspicion is the end result will make for a cracking good read. I am hoping for a mix – everything from lessons learnt from early adopters to introductions to elements of the platform to getting technologies such as Ruby up and running on Azure. 10 to 20 articles sound about right – which means I am after 10 to 20 authors :) All I need from you right now is: One or two suggestions of topics you would like to cover A pointer to any example of your previous work – which could be as simple as a blog post or a work document. For simplicity, just drop me an email direct to eric.nelson A@T microsoft.com. BIG THANKS! Eric The provisional dates are: Confirm authors and topics by 3rd May Get first draft from all authors by 10th May Complete reviews by 17th May Final versions by 24th May Published by 31st May And finally, an example: To give you an idea of what I have in mind, check out the eBook we pulled together last December which has had several thousand downloads. However I’m thinking of making this one a little bit more fun/informal. More on that later. UK MSDN Flash eBook Best Technical Articles #2 - ericnel Related Links: Spread the word – 6 Weeks of FREE Azure Training UK Azure Online Community – join today. UK Windows Azure Site Start working with Windows Azure

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  • Can I use a wireless-N laptop as an NAS for seamless and fast data transfer and access?

    - by techaddict
    I have a nice spare laptop (Dell 15R, one year old) that I was wondering if I could use as an NAS. The laptop has an E-Sata port, and I was wondering if I could set it up and plug in a few hard drives permanently (meaning I won't be unplugging it) to the eSata port and use the laptop as a wireless NAS to seamlessly and wirelessly store and access my files. To see more about what I'm looking for in the NAS to see if it's possible to use my other laptop for this purpose, see my other question: Is it possible to have a wireless in-house NAS with wireless data transfer rates of equivalent to SATA speeds? Alternatively, would it be better to sell the laptop and buy a dedicated NAS?

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  • Missing over 100GB of Space on sda1 RHEL

    - by WifiGhost
    I have a server setup with a RAID 5 using (3) 500GB drives, 1 as a spare so unused in the RAID. So in my mind i start out with 990GB with the RAID 5 in place. When looking at DF or the built in disk space utility i only see a total of about 882GB, how can i find where the 100+GB went? How can i get it back? I've checked the RAID 5 BIOS and i see all the space. I've tried looking manually and through terminal commands with no luck. Filesystem - 1K-blocks - Used Available - Use% - Mounted on /dev/mapper/vg_web-lv_root 838084192 48368700 747153060 7% / tmpfs 12104644 592 12104052 1% /dev/shm /dev/sda1 495844 121546 348698 26% /boot /dev/mapper/vg_web-lv_home 82569904 259136 78116468 1% /home Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_web-lv_root 800G 47G 713G 7% / tmpfs 12G 592K 12G 1% /dev/shm /dev/sda1 485M 119M 341M 26% /boot /dev/mapper/vg_web-lv_home 79G 254M 75G 1% /home

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  • VMware Virtualisation - Convert 64bit Windows Server to 32bit VM?

    - by dannymcc
    I have just started playing around with Vmware sphere and have the hypervisor OS installed on a spare HP ProLiant DL360 G4. I have created a test virtual machine running Ubuntu which has worked well. As a test project I wanted to convert a powered on server running Windows Server 2008 64bit into a virtual machine. As soon as I ran the Vmware Go software to start the conversion it became apparent that I cannot run 64bit guest OS's on that particular server. So, is there a way of migrating 64bit to 32bit during the conversion?

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  • UTP cable for telephone line possible?

    - by Chris
    Hi, One of my customers has build a new house with pre-installed cables for internet. The only thing he didn't think about was installing a cable for his telephone line. Behind his desk, he has a "spare" UTP cable, my question. Can this cable be used to replace a telephone line. This client has a internet and telephony contract, using a experiabox phone/internet modem. Any help would be great. I knowe I have to use a RJ11 plug.

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  • Mac OSX Server - Mac Mini to XServe Migration

    - by notpeter
    If I build out a Mac OSX Server install on a Mac Mini and then when it's ready for production I image the disks to an XServe, is there any reason the resulting system won't just work? Assuming I'm able to keep the same IP address are there any other issues I should be aware of? I'll be running minimal services, just AFP, SMB and Open Directory. TMI: My Intel XServe is full of cruft. Was originally a G4 XServe running 10.3, upgraded to 10.4 then migrated to 10.5 on the Intel XServe. I'd like a clean start, but can't spare the XServe downtime while I build out the install, can I just use a Mac Mini for dev and then switch to the XServe for production.

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  • Engineers are using explosives to remove hard rock outside our office building. What countermeasures should we take?

    - by Karrax
    Our building is located approx. 100 meters from the explosive charges. They happen several times per day, and really shake the entire building a lot. This is going to go on for many days and the blasts are supposed to get stronger. Our server rooms are nothing fancy; one of them has all the racks on hard concrete while the other one has a raised floor (the one which allows the cables to go beneath it). Does anyone have any tips, countermeasures or best practices for us? Currently we are thinking of the following countermeasures: Daily report of the server rooms status lights (HD lights, power supplies and so on). Nightly check disk scan on the most important servers Order in extra supply of spare harddrives Edit: Many good answers here! However one needs to be accepted. The highest voted answer at the time of this edit will get their answer accepted.

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  • Sorry about the wait.

    - by Ratman21
    In the last two days have been trying remove “Iolo System Mechanic Professional” (With anti-virus and FireWall) from 3 of the 5 pc’s we have (3 lap tops and two Desk tops) as it was going to expire on the 13th.   So I could replace them with a free anti-virus (AVG) and just use the windows fire wall. I have been using the same set up on one of my desk tops (XP Pro) for 8 months and one of the Lap tops (Vista) for 5 months.   The problem was that System Mechanic did not want to go. Even after using the uninstall option on the desk top (my main PC, well its that because has the larger of all the PC’s hard drives but, is the oldest and runs XP home) and using Ccleaner to try and remove it.  It was still showing up as there and after I went a head and tried installing AVG and ran it. I found that the TCP/IP module was missing.  So no internet, I had to restore the PC back to the 1st to get the module back and then install AVG (after making sure window firewall was back on. I didn’t check that on the first try). Got the PC back to normal, very late last night. Only one of the two lap tops was easy but, even at that there are still some parts of System Mechanic on it but, AVG and firewall are working.   I may try an hunt down parts of System Mechanic on it and delete them on this lap top. Which was what finally had to do on the one of the Lap tops (also XP Home) as it would not uninstall after I restored the PC back to the 4th. So delete, delete, delete and Ccleaner (one dl file would not delete though). And I just finish installing AVG and now running a scan on the lap top. So all of this took two days (well three counting today). I started late Friday night and just finishing up now.   I only started this switch over after I had finished my Job search for day on Friday.   As for blogging on Tuesday, Wednesday and Thursday, I was busy and by the end of the day was too tired to blog, that and was hung up still on that 2nd dare of The Love Dare. So I cleaned the house, while she was out of the house. I mean, I cleaned, not just vacuumed house I cleaned the kitchen counter tops and the sinks. Did the dishes and some of the laundry over two of the those days.   As to the third day of Love Dare which is “Love is not selfish” and the dare “Whatever you put your time, energy, and money into will become more important to you. It’s hard to care for something you are not investing in. Along with restraining from negative comments, buy your spouse something that says, I was thinking of you today.”   Being on a very limited income, a lot of normal guy buying for girls is out (for one thing, the comment why did you waste our money on flowers, etc, etc, would come up. Not from me though). So that one is on hold till money issues are not a problem (no that does not mean never). The 4th day “Love is thoughtful” and the dare “Contact your spouse sometime during the business of the day. Have no agenda other than asking how he or she is doing and if there is anything you could do for them”.   I did this dare while I was still working with census last week and trying to do the dares. Well I start my CCNA classes Monday the 15th and I move on to the next Love Dare day “Love is not rude”.

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  • SO-overflow induced passivity - how to cope?

    - by Ruben
    After not really working on my pet project for a while, I discovered Stackoverflow and upon perusing it more intensely I was quite amazed. I'm a bit of a perfectionist, so when I found eye-openers here highlighting many of the mistakes I made, I first wanted to fix everything. However, it's a pet project for a reason: I'm self-taught and I'm studying psychology, so programming skills can never become priority one (though it often helps, even in this field). Issues that stuck out were numerous security issues (e.g. CSRF-prevention and bcrypt eluded me) not object-oriented (at least the PHP part, the JS-part mostly is) no PHP framework used, so many of my DIY takes on commonly-tackled components (auth, ...) are either bad or inefficient really poor MySQL usage (no prepared statements, mysql extension, heard about setting proper indices two days ago) using mootools even though JQuery seems to be fashionable, so there's more probably always going to be better integration with services I'd like to use (like google visualization) So, my SO-induced frenzy turned into passivity. I can't do it all (soon) in the rather small amount of spare time I can spend on working on my project. I can leave some of the issues be in good conscience (speed stuff: an unfinished & unpublished project will never become popular, right?). No clear conscience without good security though and if I don't use a framework for auth and other complex stuff I'll regret having to do it myself. One obvious answer would probably be going open-source, but I think the project would need to become more impressive before others would commit to it. I can't afford to employ someone either. I do think the project deserves being worked on, though. How should I tackle it anyway? What's the best practice for little-practice people?

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  • Graphics card failure, anything I could try...

    - by ILMV
    My gaming PC has decided to die, it's not the first time but usually a quick ATX reset brings it back to life. Today it didn't. I disconnect all unessasary devices so I've only got the case button / LED cables, GPU, CPU, RAM and power connected, the computer still didn't turn on. I've not got a speaker on my motherboard so found a spare one I have for testing and when the machine starts up I get one long beep and two short beeps from my Award BIOS, which apparently means a video card error. I change it with the GPU from another machine and all works well. Q: So I have a faulty graphics card (an nVidia 8800GT OC), is there anything I can try to resurect it?

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  • Developing professionally for iOS, Android and web - an insight

    - by Scott Roberts
    This is not really a question on how to develop all three, I know various cross platform ways and so on. But I more want to know from developer standpoint how hard it is to basically develop iOS, Android and web apps? I am currently in my first job as a mobile/web developer. I have already developed my first iPhone/iPad app and now I have to develop the app for android because the web version I tried just didn't perform as well as needed and web databases just did not seem to make the cut. But I am not sure it's possible to be good at developing all 3 in terms of remembering all the api's etc. I wouldn't say I have an issue with the programming languages just how to use the api's for the various platforms. Also, all the other languages I look at, in my spare time, just feel like I am spreading myself to thin. Is it feasible for one person to be developing ios, android and web apps? Should I think about reducing it to iOS and web based apps? I develop everything by myself, so I have no one to discuss what the best solutions are for everything and I am just trying to workout as I go along. So any cross platform developers out there? Do companies have different teams for different platforms? Any insight would just help me get my head together. Hopefully this question makes sense.

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  • Access Denied

    - by Tony Davis
    When Microsoft executives wake up in the night screaming, I suspect they are having a nightmare about their own version of Frankenstein's monster. Created with the best of intentions, without thinking too hard of the long-term strategy, and having long outlived its usefulness, the monster still lives on, occasionally wreaking vengeance on the innocent. Its name is Access; a living synthesis of disparate body parts that is resistant to all attempts at a mercy-killing. In 1986, Microsoft had no database products, and needed one for their new OS/2 operating system, the successor to MSDOS. In 1986, they bought exclusive rights to Sybase DataServer, and were also intent on developing a desktop database to capture Ashton-Tate's dominance of that market, with dbase. This project, first called 'Omega' and later 'Cirrus', eventually spawned two products: Visual Basic in 1991 and Access in late 1992. Whereas Visual Basic battled with PowerBuilder for dominance in the client-server market, Access easily won the desktop database battle, with Dbase III and DataEase falling away. Access did an excellent job of abstracting and simplifying the task of building small database applications in a short amount of time, for a small number of departmental users, and often for a transient requirement. There is an excellent front end and forms generator. We not only see it in Access but parts of it also reappear in SSMS. It's good. A business user can pull together useful reports, without relying on extensive technical support. A skilled Access programmer can deliver a fairly sophisticated application, whilst the traditional client-server programmer is still sharpening his pencil. Even for the SQL Server programmer, the forms generator of Access is useful for sketching out application designs. So far, so good, but here's where the problems start; Access ties together two different products and the backend of Access is the bugbear. The limitations of Jet/ACE are well-known and documented. They range from MDB files that are prone to corruption, especially as they grow in size, pathetic security, and "copy and paste" Backups. The biggest problem though, was an infamous lack of scalability. Because Microsoft never realized how long the product would last, they put little energy into improving the beast. Microsoft 'ate their own dog food' by using Access for Microsoft Exchange and Outlook. They choked on it. For years, scalability and performance problems with Exchange Server have been laid at the door of the Jet Blue engine on which it relies. Substantial development work in Exchange 2010 was required, just in order to improve the engine and storage schema so that it more efficiently handled the reading and writing of mails. The alternative of using SQL Server just never panned out. The Jet engine was designed to limit concurrent users to a small number (10-20). When Access applications outgrew this, bitter experience proved that there really is no easy upgrade path from Access to SQL Server, beyond rewriting the whole lot from scratch. The various initiatives to do this never quite bridged the cultural gulf between Access and a true relational database So, what are the obvious alternatives for small, strategic database applications? I know many users who, for simple 'list maintenance' requirements are very happy using Excel databases. Surely, now that PowerPivot has led the way, it is time for Microsoft to offer a new RAD package for database application development; namely an Excel-based front end for SQL Server Express. In that way, we'll have a powerful and familiar front end, to a scalable database, and a clear upgrade path when an app takes off and needs to go enterprise. Cheers, Tony.

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  • postgres memory allocation tuning 2

    - by pstanton
    i've got a Ubuntu Linux system with 12Gb memory most of which (at least 10Gb) can be allocated solely to postgres. the system also has a 6 disk 15k SCSI RAID 10 setup. The process i'm trying to optimise is twofold. firstly a single threaded, single connection will do many inserts into 2-4 tables linked by foreign key. secondly many different complex queries are run against the resulting data, using group by extensively. this part especially needs to be optimised. i have four of these processes running at once in order to make use of the quad core CPU, therefore there will generally be no more than 5 concurrent connections (1 spare for admin tasks). what configuration changes to the default Postgres config would you recommend? I'm looking for the optimum values for things like work_mem, shared_buffers etc. relevant doco thanks!

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  • mini linux for browsing media playing

    - by Martin Beckett
    I'm looking for a small linux install (<100Mb) that can just run a browser and ideally a media player. It's to fit in a spare recovery partition on my laptop and be a quick boot for non-work stuff when I'm on the road. I have used Puppy-linux and DSL before but they have lots of stuff I don't need. Is there something like these that just concentrates on running a browser in the way xbmc does for videos? ps. The size requirement was to fit in the existing 100Mb win7 recovery partition, but that can be resized. The main idea was something that booted very quickly without the 10min wait while windows does all the corporate stuff and realizes it isn't on the LAN - and could be shutdown instantly.

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  • write-through RAM disk, or massive caching of file system?

    - by Will
    I have a program that is very heavily hitting the file system, reading and writing randomly to a set of working files. The files total several gigabytes in size, but I can spare the RAM to keep them all mostly in memory. The machines this program runs on are typically Ubuntu Linux boxes. Is there a way to configure the file system to have a very very large cache, and even to cache writes so they hit the disk later? I understand the issues with power loss or such, and am prepared to accept that. Crashing aside, in normal operation the writes should eventually reach the disk! Or is there a way to create a RAM disk that writes-through to real disk?

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  • Handy SQL Server Functions Series (HSSFS) Part 2.0 - Prelude to Parsing Patterns Properly

    - by Most Valuable Yak (Rob Volk)
    In Part 1 of the series I wrote about 2 lesser-known and somewhat undocumented functions. In this part, I'm going to cover some familiar string functions like Substring(), Parsename(), Patindex(), and Charindex() and delve into their strengths and weaknesses. I'm also splitting this part up into sub-parts to help focus on a particular technique and/or problem with the technique, hence the Part 2.0. Consider this a composite post, or com-post, if you will. (It may just turn out to be a pile of sh_t after all) I'll be using a contrived example, perhaps the most frustratingly useful, or usefully frustrating, function in SQL Server: @@VERSION. Contrived, because there are better ways to get the information (which I'll cover later); frustrating, because of the way Microsoft formatted the value; and useful because it does have 1 or 2 bits of information not found elsewhere. First let's take a look at the output of @@VERSION: Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (Intel X86) Apr 2 2010 15:53:02 Copyright (c) Microsoft Corporation Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3) There are 4 lines, with lines 2-4 indented with a tab character.  In case your browser (or this blog software) doesn't show it correctly, I gave each line a different color.  While this PRINTs nicely, if you SELECT @@VERSION in grid mode it all runs together because it ignores carriage return/line feed (CR/LF) characters.  Not fatal, but annoying. Note that @@VERSION's output will vary depending on edition and version of SQL Server, and also the OS it's installed on.  Despite the differences, the output is laid out the same way and the relevant pieces are in the same order. I'll be using the following view for Parts 2.1 onward, so we have a nice collection of @@VERSION information: create view version(SQLVersion,VersionString) AS ( select 2000, 'Microsoft SQL Server 2000 - 8.00.2055 (Intel X86) Dec 16 2008 19:46:53 Copyright (c) 1988-2003 Microsoft Corporation Developer Edition on Windows NT 5.1 (Build 2600: Service Pack 3)' union all select 2005, 'Microsoft SQL Server 2005 - 9.00.4053.00 (Intel X86) May 26 2009 14:24:20 Copyright (c) 1988-2005 Microsoft Corporation Developer Edition on Windows NT 5.1 (Build 2600: Service Pack 3)' union all select 2008, 'Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (Intel X86) Apr 2 2010 15:53:02 Copyright (c) Microsoft Corporation Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3)' union all select 2005, 'Microsoft SQL Server 2005 - 9.00.3080.00 (Intel X86) Sep 6 2009 01:43:32 Copyright (c) 1988-2005 Microsoft Corporation Standard Edition on Windows NT 5.2 (Build 3790: Service Pack 2)' union all select 2008, 'Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (X64) Apr 2 2010 15:48:46 Copyright (c) Microsoft Corporation Developer Edition (64-bit) on Windows NT 6.1 <X64> (Build 7600: ) (Hypervisor)' union all select 2008, 'Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (X64) Apr 2 2010 15:48:46 Copyright (c) Microsoft Corporation Express Edition with Advanced Services (64-bit) on Windows NT 6.1 <X64> (Build 7600: ) (Hypervisor)' ) Feel free to add your own @@VERSION info if it's not already there. In Part 2.1 I'll focus on extracting the SQL Server version number (10.50.1600.1 in first example) and the Edition (Developer), but will have a solution that works with all versions.  Stay tuned!

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  • How do graphics programmers deal with rendering vertices that don't change the image?

    - by canisrufus
    So, the title is a little awkward. I'll give some background, and then ask my question. Background: I work as a web GIS application developer, but in my spare time I've been playing with map rendering and improving data interchange formats. I work only in 2D space. One interesting issue I've encountered is that when you're rendering a polygon at a small scale (zoomed way out), many of the vertices are redundant. An extreme case would be that you have a polygon with 500,000 vertices that only takes up a single pixel. If you're sending this data to the browser, it would make sense to omit ~499,999 of those vertices. One way we achieve that is by rendering an image on a server and and sending it as a PNG: voila, it's a point. Sometimes, though, we want data sent to the browser where it can be rendered with SVG (or canvas, or webgl) so that it can be interactive. The problem: It turns out that, using modern geographic data sets, it's very easy to overload SVG's rendering abilities. In an effort to cope with those limitations, I'm trying to figure out how to visually losslessly reduce a data set for a given scale and map extent (and, if necessary, for a known map pixel width and height). I got a great reduction in data size just using the Douglas-Peucker algorithm, and I believe I was able to get it to keep the polygons true to within one pixel. Unfortunately, Douglas-Peucker doesn't preserve topology, so it changed how borders between polygons got rendered. I couldn't readily find other algorithms to try out and adapt to the purpose, but I don't have much CS/algorithm background and might not recognize them if I saw them.

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  • SQL Server: One 12-drive RAID-10 array or 2 arrays of 8-drives and 4-drives

    - by ben
    Setting up a box for SQL Server 2008, which would give the best performance (heavy OLTP)? The more drives in a RAID-10 array the better performance, but will losing 4 drives to dedicate them to the transaction logs give us more performance. 12-drives in RAID-10 plus one hot spare. OR 8-drives in RAID-10 for database and 4-drives RAID-10 for transaction logs plus 2 hot spares (one for each array). We have 14-drive slots to work with and it's an older PowerVault that doesn't support global hot spares.

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