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  • Windows Explorer slow response when disconnect from the network

    - by ITGuy24
    As a Systems Admin I have seen this issue repeatedly and it drives me crazy. Basically the problem occurs when you open My Documents or My Computer (Windows Explorer) there is a big delay ranging from 5-25 seconds before it actually opens and shows the content. Sometimes the problem continues with each subfolder you open. The problem is most common when disconnected from the network and when you have mapped drives. The most common solution for this problem is to disconnect any mapped drives or printers that are discconected/not reaachable. I have also heard that turning off "Automatically search for network folders and printers" can solve this issue but I have yet to see this work. Does anyone know of any other work arounds for this?

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  • Cannot access Network Shares on Windows Server 2008 running VisualSVN Server

    - by mwillmott
    I have installed VisualSVN server on Windows Server 2008. The server is part of a domain but not the domain controller, it is just a data server and now an SVN server. VisualSVN uses port 80 and can only be access from inside the network (i do i by going to the dns name of the server). However, ever since i have installed this, other computers on the network can no longer access the shared folders on the server EXCEPT the domain controller which has no problems accessing the shares. I am stumped, i am guessing it is something to do with Apache running and not using host-headers (or whatever the Apache equivalent may be) but just being bound to the servers DNS name or IP. Any suggestions?

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  • Network topology question

    - by Asbie
    We currently have three networks, X.X.163.1, X.X.93.1 and 192.168.1.1. Today's setup is like this: http://i.imgur.com/tkKWy.jpg We now have PPT VPN from internet to the X.X.163.1-network, but really need to access the files from the File Server through VPN. I am also aware that this setup is not optimal. So please, any advices on how to redesign our network? Rack servers are mostly web and db servers, with only public IP addresses.

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  • Disabling at application level a nic (network interface) on Windows

    - by Leandro
    How can I disable at application level a network interface? The main question is this: If I disable the nic trough wmic (win7) or devcon (XP), the "plug and play" of a wired nic doesn't work any more. For example, if the user put the cable on a disabled nic, the OS doesn't know about it. So I need to persist the enable condition but disabling the networking like a disable nic. There's some API, network configuration (routing, changing ip, changing gateway, any), .NET Framework resource (Only NetFramework 2.0) or do you can think in any workaround to do this? Suggest and ideas also will be treated as a solution. Thanks and kind regards.

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  • My computer is listed twice in the Network view; network shares are not accessible

    - by romkyns
    I have a couple of network shares set up on my Win7 machine. They've been in constant use, from that same machine on which they're set up. One morning they just randomly stopped working: When I went looking for what was wrong, I noticed that I also had my PC listed twice in the Network view in Explorer: "Sirius" is the name of the PC on which these screenshots were taken. I may have installed some windows updates around the time this happened. I have since tried rebooting and installing all the latest updates, to no avail. I've also removed the share in question and re-added it, making sure I give all rights to everyone. I'm an administrator on this machine, but I can't access the administrative shares (\\SIRIUS\c$) either, with the same message. I can access \\localhost\AcronisImages and \\localhost\c$, and I can ping sirius. Any ideas?

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  • Get active network interface on Windows

    - by Kevin Walzer
    I'm developing an application that provides a UI to windump, the packet sniffer. Windump has a "-D" parameter that lists all network interfaces it can find, and then you can specify which interface to listen on. However, I'd like to avoid forcing the user to manually configure which interface to listen on. On Unix, I can obtain the right network interface (en0, en1, etc.) via a call to ifconfig and some parsing of the output, but I cannot locate any equivalent Windows API or command that can yield similar information--ipconfig doesn't seem to obtain this data. Can anyone suggest either a Windows command-line tool or an API that can be called via VBScript to obtain this data so that I don't have to present the user with a dialog in my GUI telling them to select the right interface?

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  • TV network capabilities.

    - by Narcolapser
    Question: Can the major TV producer's internet TV systems access network resource? Info: I'm looking for large TV's right now for my company to set up in conference rooms. We want the ability to load presentations with out having to have a computer to do so. Our hope is to put things on to network drives and access and display them from there. I've heard that LG's can do this if you convert the power point file in to a show format. that's fine. I just need to get this information to the TV with out the computer attached. Can anyone tell me if companies like LG, Vizio, Sony, Samsung, etc. have TV's that are capable of doing this? Thanks ~n

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  • Un-balanced network speed although using fiberoptic cable line

    - by Hoàng Long
    I'm not sure this is a right place to ask this question, but there's a strange thing that I don't quite sure what the reason is. My company has hired a fiberoptic cable line for network use (Wifi and cable through a router). But the strange thing is that, whenever someone view YouTube or listen stream music, then network speed for all the others become extremely slow. The download speed for that person is about 4-5 MB/s (or more), but others suffer. I'm still a newbie about networking. But I know there should be a solution. Could anyone tell me a way to stop this bad behavior? It's not possible for asking people not viewing YouTube, since that's part of their jobs. Any insights about this problem would be very welcome.

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  • Error message when renaming files on a network drive stored in Windows 7 favorites

    - by paulmorriss
    I have a network drive mapped to a share on a Window Server 2003. I have a shortcut to this drive stored in my Windows 7 favorites. When I double click the shortcut and then rename a file on the drive, if the file is longer than 8 chars or contains spaces then I get this error The drive that this file or folder is stored on does not allow long file names, or names containing blanks or any of the following characters:... If I get to the network drive by click on it in the tree under computer then it works fine. Is there a way to get round this?

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  • Network with bridge and port forwarding?

    - by rafek
    Hi! Below is my current (and planned) home network configuration. I would like to connect my non-wifi-capable desktop to my home network. The question is: HOW? What device do I need? The primary requiremen is that I need to be able to forward ports to my desktop. How would I achieve this? Is there something like "double port forwarding"? Could anyone please explain this configuration to me? Thank you in advance!

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  • Enumerating network shares with NetBIOS

    - by Karrax
    Hello, I have a case where I need to find all connectable shares on my network, and preferably as much information about the share possible. I could do this manually but its quite a big network and it would be too slow. If I did it manually Im guessing I would do something like net view net use //hostname <browse it manually> This would however not give me hidden shares so its not a viable option. Does anyone know of a tool which can help me out in this case? I already tried Sysinternals ShareEnum but it did not work properly. It did a half decent job, but it gave me access denied on tons of shares that was actually open. Any tips in how I can script this is also appriciated. Thank you

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  • Network Monitoring Tool Recommendation

    - by user42801
    Hello, My company is looking for a monitoring app/tool that would allow us to capture and graph statistics on network performance. As a starting point, we would like to ping remote host(s) and gateway(s) from several of our servers, grab an average of the ping times from each of our servers to the remote host(s), and then graph it (preferably in a central location). Also, we would like to be able to graph the results for time frames as short as a week to as long as 6 months. It is reasonable to expect that we would ask more of the selected monitoring app/tool as we come up with other key network performance indicators in the future. So an app with great flexibility and features would be ideal. Upon first glance, Cacti looks like it might be a fit. Any other recommendations? Thanks in advance for any input.

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  • Why doesn't the network drive not automatically connect?

    - by Sheldon
    I've set up samba on my Ubuntu desktop. It appears to be something to do with the server. With all user accounts on Ubuntu(except the default one I use all the time) windows isn't able to/doesn't automatically map the network drive. In other words: I am only able to to automatically map the network drive on windows with only one of the accounts created on Ubuntu. Edit: I am able to connect using other accounts, I'm just not able to automatically map using those credentials. Details: Windows 7, Ubuntu 12.10

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  • Troubleshooting Network Speeds -- The Age Old Inquiry

    - by John K
    I'm looking for help with what I'm sure is an age old question. I've found myself in a situation of yearning to understand network throughput more clearly, but I can't seem to find information that makes it "click" We have a few servers distributed geographically, running various versions of Windows. Assuming we always use one host (a desktop) as the source, when copying data from that host to other servers across the country, we see a high variance in speed. In some cases, we can copy data at 12MB/s consistently, in others, we're seeing 0.8 MB/s. It should be noted, after testing 8 destinations, we always seem to be at either 0.6-0.8MB/s or 11-12 MB/s. In the building we're primarily concerned with, we have an OC-3 connection to our ISP. I know there are a lot of variables at play, but I guess I was hoping the experts here could help answer a few basic questions to help bolster my understanding. 1.) For older machines, running Windows XP, server 2003, etc, with a 100Mbps Ethernet card and 72 ms typical latency, does 0.8 MB/s sound at all reasonable? Or do you think that slow enough to indicate a problem? 2.) The classic "mathematical fastest speed" of "throughput = TCP window / latency," is, in our case, calculated to 0.8 MB/s (64Kb / 72 ms). My understanding is that is an upper bounds; that you would never expect to reach (due to overhead) let alone surpass that speed. In some cases though, we're seeing speeds of 12.3 MB/s. There are Steelhead accelerators scattered around the network, could those account for such a higher transfer rate? 3.) It's been suggested that the use SMB vs. SMB2 could explain the differences in speed. Indeed, as expected, packet captures show both being used depending on the OS versions in play, as we would expect. I understand what determines SMB2 being used or not, but I'm curious to know what kind of performance gain you can expect with SMB2. My problem simply seems to be a lack of experience, and more importantly, perspective, in terms of what are and are not reasonable network speeds. Could anyone help impart come context/perspective?

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  • Optimize Windows file access over network

    - by Djizeus
    At my company I frequently need to access shared files over a Windows network. These files are located on the other side of the planet, so I guess the file share goes through some kind of VPN over Internet, but I don't control this and it is supposed to be "transparent" for me. However it is extremely slow. Displaying the content of a directory in the file explorer takes about 10s. Even if over the Internet, I did not expect that retrieving a list of file names would be that long. Are there any settings to optimize this from my Windows XP workstation, or is it mostly related to the way the network is configured? The only thing I have found so far is to cache all file names, while by default only short file names are cached (http://support.microsoft.com/kb/843418).

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  • Exchange 2010 allows outside access to network files

    - by user2891127
    One of our users discovered by accident he could access our network files from his smartphone while at home. No VPN needed. He was sent an email with an internal link to a network share on his android. When he opened the email and clicked on the link, he could browse our files while at home. Looking at the access logs, the connection to the share and files he accessed came from our mail server (Exchange 2010). We have no sharepoint servers running at all, and certainly not on the Exchange server. What is this function/feature called, and is it possible to turn this function/feature off? Should I turn this off?

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  • batch file to disable network share on Windows XP

    - by Robb
    Loosely related to this question Network Share causing Cygwin to run slowly after 'ls', I'd like to write a little batch file that I can execute to disconnect the host from any network shares and subsequently another batch file to reconnect. Ideally, this would be something that I can execute from a PuTTY terminal, SSHed into the box running cygwin. I'm pretty sure the batch files can be written easily, but I don't know about executing them from a PuTTY terminal. Regardless, I'd still like the batchfiles anyways. For the sake of simplicity my process would be: Log into server via PuTTY Run batch files to disconnect shares Do what I need to do Run batch files to reconnect shares Exit session, closing PuTTY

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  • Windows 7 Mapped Network Drive Multiplying to Create Duplicates all the way to Z:

    - by bendiy
    A strange issue came in today from some users. At least two Windows 7 x64 boxes that have duplicate mappings of a network drive. The drive is not mapped with a log in script, but done manual through "Map Network Drive". Everything has been fine for months, but all of the sudden, Explorer looks like this: Files (\\fileServerPath) (S:) Files (\\fileServerPath) (T:) Files (\\fileServerPath) (U:) Files (\\fileServerPath) (V:) Files (\\otherServerPath) (W:) Files (\\fileServerPath) (X:) Files (\\fileServerPath) (Y:) Files (\\fileServerPath) (Z:) There are some other networks drives mixed in there that did not duplicate. The drive is normally mapped to S:\, but it decided to make its way to Z:. What is going on here? I've found this and will be trying soon: http://social.technet.microsoft.com/Forums/en/w7itpronetworking/thread/b5647cc3-15d0-4776-bb00-a869bd8f930b

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  • Windows 7 not showing other computers on network

    - by user24559
    I have several other machines that are on other operating systems (XP, etc.) and they show up just fine on other machines NOT running Windows 7. However, they do not show on the Windows 7 "Network" area. I can directly access them by typing the computer (\\mycomputer), then they show up on the list. However, they don't stick around and when I close Windows Explorer and open it again, the computer is not listed again in Network. There was never a problem using Windows XP where all the machines showed up just fine. This is not an access problem but a listing problem.

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  • SSIS Lookup component tuning tips

    - by jamiet
    Yesterday evening I attended a London meeting of the UK SQL Server User Group at Microsoft’s offices in London Victoria. As usual it was both a fun and informative evening and in particular there seemed to be a few questions arising about tuning the SSIS Lookup component; I rattled off some comments and figured it would be prudent to drop some of them into a dedicated blog post, hence the one you are reading right now. Scene setting A popular pattern in SSIS is to use a Lookup component to determine whether a record in the pipeline already exists in the intended destination table or not and I cover this pattern in my 2006 blog post Checking if a row exists and if it does, has it changed? (note to self: must rewrite that blog post for SSIS2008). Fundamentally the SSIS lookup component (when using FullCache option) sucks some data out of a database and holds it in memory so that it can be compared to data in the pipeline. One of the big benefits of using SSIS dataflows is that they process data one buffer at a time; that means that not all of the data from your source exists in the dataflow at the same time and is why a SSIS dataflow can process data volumes that far exceed the available memory. However, that only applies to data in the pipeline; for reasons that are hopefully obvious ALL of the data in the lookup set must exist in the memory cache for the duration of the dataflow’s execution which means that any memory used by the lookup cache will not be available to be used as a pipeline buffer. Moreover, there’s an obvious correlation between the amount of data in the lookup cache and the time it takes to charge that cache; the more data you have then the longer it will take to charge and the longer you have to wait until the dataflow actually starts to do anything. For these reasons your goal is simple: ensure that the lookup cache contains as little data as possible. General tips Here is a simple tick list you can follow in order to tune your lookups: Use a SQL statement to charge your cache, don’t just pick a table from the dropdown list made available to you. (Read why in SELECT *... or select from a dropdown in an OLE DB Source component?) Only pick the columns that you need, ignore everything else Make the database columns that your cache is populated from as narrow as possible. If a column is defined as VARCHAR(20) then SSIS will allocate 20 bytes for every value in that column – that is a big waste if the actual values are significantly less than 20 characters in length. Do you need DT_WSTR typed columns or will DT_STR suffice? DT_WSTR uses twice the amount of space to hold values that can be stored using a DT_STR so if you can use DT_STR, consider doing so. Same principle goes for the numerical datatypes DT_I2/DT_I4/DT_I8. Only populate the cache with data that you KNOW you will need. In other words, think about your WHERE clause! Thinking outside the box It is tempting to build a large monolithic dataflow that does many things, one of which is a Lookup. Often though you can make better use of your available resources by, well, mixing things up a little and here are a few ideas to get your creative juices flowing: There is no rule that says everything has to happen in a single dataflow. If you have some particularly resource intensive lookups then consider putting that lookup into a dataflow all of its own and using raw files to pass the pipeline data in and out of that dataflow. Know your data. If you think, for example, that the majority of your incoming rows will match with only a small subset of your lookup data then consider chaining multiple lookup components together; the first would use a FullCache containing that data subset and the remaining data that doesn’t find a match could be passed to a second lookup that perhaps uses a NoCache lookup thus negating the need to pull all of that least-used lookup data into memory. Do you need to process all of your incoming data all at once? If you can process different partitions of your data separately then you can partition your lookup cache as well. For example, if you are using a lookup to convert a location into a [LocationId] then why not process your data one region at a time? This will mean your lookup cache only has to contain data for the location that you are currently processing and with the ability of the Lookup in SSIS2008 and beyond to charge the cache using a dynamically built SQL statement you’ll be able to achieve it using the same dataflow and simply loop over it using a ForEach loop. Taking the previous data partitioning idea further … a dataflow can contain more than one data path so why not split your data using a conditional split component and, again, charge your lookup caches with only the data that they need for that partition. Lookups have two uses: to (1) find a matching row from the lookup set and (2) put attributes from that matching row into the pipeline. Ask yourself, do you need to do these two things at the same time? After all once you have the key column(s) from your lookup set then you can use that key to get the rest of attributes further downstream, perhaps even in another dataflow. Are you using the same lookup data set multiple times? If so, consider the file caching option in SSIS 2008 and beyond. Above all, experiment and be creative with different combinations. You may be surprised at what works. Final  thoughts If you want to know more about how the Lookup component differs in SSIS2008 from SSIS2005 then I have a dedicated blog post about that at Lookup component gets a makeover. I am on a mini-crusade at the moment to get a BULK MERGE feature into the database engine, the thinking being that if the database engine can quickly merge massive amounts of data in a similar manner to how it can insert massive amounts using BULK INSERT then that’s a lot of work that wouldn’t have to be done in the SSIS pipeline. If you think that is a good idea then go and vote for BULK MERGE on Connect. If you have any other tips to share then please stick them in the comments. Hope this helps! @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • [GEEK SCHOOL] Network Security 4: Windows Firewall: Your System’s Best Defense

    - by Ciprian Rusen
    If you have your computer connected to a network, or directly to your Internet connection, then having a firewall is an absolute necessity. In this lesson we will discuss the Windows Firewall – one of the best security features available in Windows! The Windows Firewall made its debut in Windows XP. Prior to that, Windows system needed to rely on third-party solutions or dedicated hardware to protect them from network-based attacks. Over the years, Microsoft has done a great job with it and it is one of the best firewalls you will ever find for Windows operating systems. Seriously, it is so good that some commercial vendors have decided to piggyback on it! Let’s talk about what you will learn in this lesson. First, you will learn about what the Windows Firewall is, what it does, and how it works. Afterward, you will start to get your hands dirty and edit the list of apps, programs, and features that are allowed to communicate through the Windows Firewall depending on the type of network you are connected to. Moving on from there, you will learn how to add new apps or programs to the list of allowed items and how to remove the apps and programs that you want to block. Last but not least, you will learn how to enable or disable the Windows Firewall, for only one type of networks or for all network connections. By the end of this lesson, you should know enough about the Windows Firewall to use and manage it effectively. What is the Windows Firewall? Windows Firewall is an important security application that’s built into Windows. One of its roles is to block unauthorized access to your computer. The second role is to permit authorized data communications to and from your computer. Windows Firewall does these things with the help of rules and exceptions that are applied both to inbound and outbound traffic. They are applied depending on the type of network you are connected to and the location you have set for it in Windows, when connecting to the network. Based on your choice, the Windows Firewall automatically adjusts the rules and exceptions applied to that network. This makes the Windows Firewall a product that’s silent and easy to use. It bothers you only when it doesn’t have any rules and exceptions for what you are trying to do or what the programs running on your computer are trying to do. If you need a refresher on the concept of network locations, we recommend you to read our How-To Geek School class on Windows Networking. Another benefit of the Windows Firewall is that it is so tightly and nicely integrated into Windows and all its networking features, that some commercial vendors decided to piggyback onto it and use it in their security products. For example, products from companies like Trend Micro or F-Secure no longer provide their proprietary firewall modules but use the Windows Firewall instead. Except for a few wording differences, the Windows Firewall works the same in Windows 7 and Windows 8.x. The only notable difference is that in Windows 8.x you will see the word “app” being used instead of “program”. Where to Find the Windows Firewall By default, the Windows Firewall is turned on and you don’t need to do anything special in order for it work. You will see it displaying some prompts once in a while but they show up so rarely that you might forget that is even working. If you want to access it and configure the way it works, go to the Control Panel, then go to “System and Security” and select “Windows Firewall”. Now you will see the Windows Firewall window where you can get a quick glimpse on whether it is turned on and the type of network you are connected to: private networks or public network. For the network type that you are connected to, you will see additional information like: The state of the Windows Firewall How the Windows Firewall deals with incoming connections The active network When the Windows Firewall will notify you You can easily expand the other section and view the default settings that apply when connecting to networks of that type. If you have installed a third-party security application that also includes a firewall module, chances are that the Windows Firewall has been disabled, in order to avoid performance issues and conflicts between the two security products. If that is the case for your computer or device, you won’t be able to view any information in the Windows Firewall window and you won’t be able to configure the way it works. Instead, you will see a warning that says: “These settings are being managed by vendor application – Application Name”. In the screenshot below you can see an example of how this looks. How to Allow Desktop Applications Through the Windows Firewall Windows Firewall has a very comprehensive set of rules and most Windows programs that you install add their own exceptions to the Windows Firewall so that they receive network and Internet access. This means that you will see prompts from the Windows Firewall on occasion, generally when you install programs that do not add their own exceptions to the Windows Firewall’s list. In a Windows Firewall prompt, you are asked to select the network locations to which you allow access for that program: private networks or public networks. By default, Windows Firewall selects the checkbox that’s appropriate for the network you are currently using. You can decide to allow access for both types of network locations or just to one of them. To apply your setting press “Allow access”. If you want to block network access for that program, press “Cancel” and the program will be set as blocked for both network locations. At this step you should note that only administrators can set exceptions in the Windows Firewall. If you are using a standard account without administrator permissions, the programs that do not comply with the Windows Firewall rules and exceptions are automatically blocked, without any prompts being shown. You should note that in Windows 8.x you will never see any Windows Firewall prompts related to apps from the Windows Store. They are automatically given access to the network and the Internet based on the assumption that you are aware of the permissions they require based on the information displayed by the Windows Store. Windows Firewall rules and exceptions are automatically created for each app that you install from the Windows Store. However, you can easily block access to the network and the Internet for any app, using the instructions in the next section. How to Customize the Rules for Allowed Apps Windows Firewall allows any user with an administrator account to change the list of rules and exceptions applied for apps and desktop programs. In order to do this, first start the Windows Firewall. On the column on the left, click or tap “Allow an app or feature through Windows Firewall” (in Windows 8.x) or “Allow a program or feature through Windows Firewall” (in Windows 7). Now you see the list of apps and programs that are allowed to communicate through the Windows Firewall. At this point, the list is grayed out and you can only view which apps, features, and programs have rules that are enabled in the Windows Firewall.

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  • The SSIS tuning tip that everyone misses

    - by Rob Farley
    I know that everyone misses this, because I’m yet to find someone who doesn’t have a bit of an epiphany when I describe this. When tuning Data Flows in SQL Server Integration Services, people see the Data Flow as moving from the Source to the Destination, passing through a number of transformations. What people don’t consider is the Source, getting the data out of a database. Remember, the source of data for your Data Flow is not your Source Component. It’s wherever the data is, within your database, probably on a disk somewhere. You need to tune your query to optimise it for SSIS, and this is what most people fail to do. I’m not suggesting that people don’t tune their queries – there’s plenty of information out there about making sure that your queries run as fast as possible. But for SSIS, it’s not about how fast your query runs. Let me say that again, but in bolder text: The speed of an SSIS Source is not about how fast your query runs. If your query is used in a Source component for SSIS, the thing that matters is how fast it starts returning data. In particular, those first 10,000 rows to populate that first buffer, ready to pass down the rest of the transformations on its way to the Destination. Let’s look at a very simple query as an example, using the AdventureWorks database: We’re picking the different Weight values out of the Product table, and it’s doing this by scanning the table and doing a Sort. It’s a Distinct Sort, which means that the duplicates are discarded. It'll be no surprise to see that the data produced is sorted. Obvious, I know, but I'm making a comparison to what I'll do later. Before I explain the problem here, let me jump back into the SSIS world... If you’ve investigated how to tune an SSIS flow, then you’ll know that some SSIS Data Flow Transformations are known to be Blocking, some are Partially Blocking, and some are simply Row transformations. Take the SSIS Sort transformation, for example. I’m using a larger data set for this, because my small list of Weights won’t demonstrate it well enough. Seven buffers of data came out of the source, but none of them could be pushed past the Sort operator, just in case the last buffer contained the data that would be sorted into the first buffer. This is a blocking operation. Back in the land of T-SQL, we consider our Distinct Sort operator. It’s also blocking. It won’t let data through until it’s seen all of it. If you weren’t okay with blocking operations in SSIS, why would you be happy with them in an execution plan? The source of your data is not your OLE DB Source. Remember this. The source of your data is the NCIX/CIX/Heap from which it’s being pulled. Picture it like this... the data flowing from the Clustered Index, through the Distinct Sort operator, into the SELECT operator, where a series of SSIS Buffers are populated, flowing (as they get full) down through the SSIS transformations. Alright, I know that I’m taking some liberties here, because the two queries aren’t the same, but consider the visual. The data is flowing from your disk and through your execution plan before it reaches SSIS, so you could easily find that a blocking operation in your plan is just as painful as a blocking operation in your SSIS Data Flow. Luckily, T-SQL gives us a brilliant query hint to help avoid this. OPTION (FAST 10000) This hint means that it will choose a query which will optimise for the first 10,000 rows – the default SSIS buffer size. And the effect can be quite significant. First let’s consider a simple example, then we’ll look at a larger one. Consider our weights. We don’t have 10,000, so I’m going to use OPTION (FAST 1) instead. You’ll notice that the query is more expensive, using a Flow Distinct operator instead of the Distinct Sort. This operator is consuming 84% of the query, instead of the 59% we saw from the Distinct Sort. But the first row could be returned quicker – a Flow Distinct operator is non-blocking. The data here isn’t sorted, of course. It’s in the same order that it came out of the index, just with duplicates removed. As soon as a Flow Distinct sees a value that it hasn’t come across before, it pushes it out to the operator on its left. It still has to maintain the list of what it’s seen so far, but by handling it one row at a time, it can push rows through quicker. Overall, it’s a lot more work than the Distinct Sort, but if the priority is the first few rows, then perhaps that’s exactly what we want. The Query Optimizer seems to do this by optimising the query as if there were only one row coming through: This 1 row estimation is caused by the Query Optimizer imagining the SELECT operation saying “Give me one row” first, and this message being passed all the way along. The request might not make it all the way back to the source, but in my simple example, it does. I hope this simple example has helped you understand the significance of the blocking operator. Now I’m going to show you an example on a much larger data set. This data was fetching about 780,000 rows, and these are the Estimated Plans. The data needed to be Sorted, to support further SSIS operations that needed that. First, without the hint. ...and now with OPTION (FAST 10000): A very different plan, I’m sure you’ll agree. In case you’re curious, those arrows in the top one are 780,000 rows in size. In the second, they’re estimated to be 10,000, although the Actual figures end up being 780,000. The top one definitely runs faster. It finished several times faster than the second one. With the amount of data being considered, these numbers were in minutes. Look at the second one – it’s doing Nested Loops, across 780,000 rows! That’s not generally recommended at all. That’s “Go and make yourself a coffee” time. In this case, it was about six or seven minutes. The faster one finished in about a minute. But in SSIS-land, things are different. The particular data flow that was consuming this data was significant. It was being pumped into a Script Component to process each row based on previous rows, creating about a dozen different flows. The data flow would take roughly ten minutes to run – ten minutes from when the data first appeared. The query that completes faster – chosen by the Query Optimizer with no hints, based on accurate statistics (rather than pretending the numbers are smaller) – would take a minute to start getting the data into SSIS, at which point the ten-minute flow would start, taking eleven minutes to complete. The query that took longer – chosen by the Query Optimizer pretending it only wanted the first 10,000 rows – would take only ten seconds to fill the first buffer. Despite the fact that it might have taken the database another six or seven minutes to get the data out, SSIS didn’t care. Every time it wanted the next buffer of data, it was already available, and the whole process finished in about ten minutes and ten seconds. When debugging SSIS, you run the package, and sit there waiting to see the Debug information start appearing. You look for the numbers on the data flow, and seeing operators going Yellow and Green. Without the hint, I’d sit there for a minute. With the hint, just ten seconds. You can imagine which one I preferred. By adding this hint, it felt like a magic wand had been waved across the query, to make it run several times faster. It wasn’t the case at all – but it felt like it to SSIS.

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