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  • How can I tell if ZFS (zfs-fuse) dedup/compression is applied to a particular file?

    - by asari
    I have a zfs formatted partition using zfs-fuse for linux (Ubuntu). I had used it for a while, and then enabled dedup and compression on it (zfs set compression=on/dedup=on). Now I think I have some files that are dedup'ed and compressed, and file that are not yet. It was OK, but sometimes I was confused. Let's see, following command would consume almost 4GB of my zfs storage: cp oldfile.4GB newfile.4GB .. and this would consume almost zero: cp newfile.4GB newfile.4GB.2 This is because the old file is not yet compressed, so dedup not happened, I think. My idea is -- if I can find old files that are not yet dedup/compressed, I can perform batch copy/rename/remove them to eliminate duplicity and redundancy. But how I can check that? I know I can re-copy whole contents of my storage should work (even better with checking the time stamp of each file), but I'd be happier if I have zfsstat-like tool that shows some file properties.

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  • How to turn on gzip compression in JBoss 5 ?

    - by Vladimir Bezugliy
    I added following file deployers\jbossweb.deployer\server.xml <Connector compression="force" compressionMinSize="512" noCompressionUserAgents="gozilla, traviata" compressableMimeType="text/html,text/xml,image/png,text/css,text/javascript"> </Connector> But fiddler shows that jboss does not compress responses. How to ensure that gzip compression in JBoss is turned on? Is it possible to check it in jmx-console?

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  • Cannot create file in directory even though it's writable by a group I belong to

    - by Alan Berndt
    I have a directory structure owned by a certain group, and I am a member of the group that owns these directories. I am able to create files in one directory, but not in another, even though the permissions are the same. alan@bricky:/mnt/storage/media$ stat Music Music\ \(Lossy\)/ File: `Music' Size: 34 Blocks: 8 IO Block: 4096 directory Device: fb00h/64256d Inode: 4215424 Links: 3 Access: (2775/drwxrwsr-x) Uid: ( 1001/ media) Gid: ( 1001/ media) Access: 2011-08-19 11:45:03.182586898 -0700 Modify: 2011-08-19 11:44:01.412840027 -0700 Change: 2011-08-19 11:45:02.734603240 -0700 File: `Music (Lossy)/' Size: 6 Blocks: 8 IO Block: 4096 directory Device: fb00h/64256d Inode: 1512056832 Links: 2 Access: (2775/drwxrwsr-x) Uid: ( 1001/ media) Gid: ( 1001/ media) Access: 2011-08-19 11:45:03.190586606 -0700 Modify: 2011-08-19 10:34:46.526530313 -0700 Change: 2011-08-19 11:45:02.738603094 -0700 alan@bricky:/mnt/storage/media$ touch Music/test alan@bricky:/mnt/storage/media$ touch Music\ \(Lossy\)/test touch: cannot touch `Music (Lossy)/test': Permission denied

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  • Why is a FLAC encoded from a decoded MP3 bigger than the MP3?

    - by Ryan Thompson
    To be more precise than in the title, suppose I have a MP3 file that is 320 kbps. If I decompress it, then logically, all the data except for roughly 320 kilobits out of each second of audio should be redundant data, able to be compressed away. So, when I encode the decompressed file to FLAC, or any other lossless codec, why is it so much larger? On a related note, is it theoretically possible to losslessly recover the source mp3 audio from a decompressed wav? (I know the mp3 itself is lossy. I'm asking if it's possible to re-encode without any further loss.) EDIT: Let me clarify the related question, and the rationale behind it. Suppose I have a wav that was decompressed from an MP3 file (and assume I don't have the mp3 itself for some reason). If I don't want to lose any more quality, I can re-encode it with FLAC or any other lossless encoder and get a larger file just to maintain the same quality. Or, I can re-encode it to mp3 again and get the same size as the original but lose more data. Obviously, neither of these cases is ideal. I can either have the original size or the original quality, but not both (I mean the quality of the original mp3, not the original lossless source). My question is: Can we get both? Is it theoretically possible to recover the lossy compressed data from the lossy decompressed data, without losing even more? If it is possible, I could imagine a lossless compression algorithm that compresses the audio with FLAC. Then it also scans the audio for any signs of previous lossy compression, and if detected, recompresses it losslessly to the original lossy file. Then it keeps whichever file is smaller.

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  • ASP.NET GZip Encoding Caveats

    - by Rick Strahl
    GZip encoding in ASP.NET is pretty easy to accomplish using the built-in GZipStream and DeflateStream classes and applying them to the Response.Filter property.  While applying GZip and Deflate behavior is pretty easy there are a few caveats that you have watch out for as I found out today for myself with an application that was throwing up some garbage data. But before looking at caveats let’s review GZip implementation for ASP.NET. ASP.NET GZip/Deflate Basics Response filters basically are applied to the Response.OutputStream and transform it as data is written to it through the ASP.NET Response object. So a Response.Write eventually gets written into the output stream which if a filter is also written through the filter stream’s interface. To perform the actual GZip (and Deflate) encoding typically used by Web pages .NET includes the GZipStream and DeflateStream stream classes which can be readily assigned to the Repsonse.OutputStream. With these two stream classes in place it’s almost trivially easy to create a couple of reusable methods that allow you to compress your HTTP output. In my standard WebUtils utility class (from the West Wind West Wind Web Toolkit) created two static utility methods – IsGZipSupported and GZipEncodePage – that check whether the client supports GZip encoding and then actually encodes the current output (note that although the method includes ‘Page’ in its name this code will work with any ASP.NET output). /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } /// <summary> /// Sets up the current page or handler to use GZip through a Response.Filter /// IMPORTANT: /// You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() { HttpResponse Response = HttpContext.Current.Response; if (IsGZipSupported()) { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (AcceptEncoding.Contains("deflate")) { Response.Filter = new System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "deflate"); } else { Response.Filter = new System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); Response.Headers.Remove("Content-Encoding"); Response.AppendHeader("Content-Encoding", "gzip"); } } } As you can see the actual assignment of the Filter is as simple as: Response.Filter = new DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress); which applies the filter to the OutputStream. You also need to ensure that your response reflects the new GZip or Deflate encoding and ensure that any pages that are cached in Proxy servers can differentiate between pages that were encoded with the various different encodings (or no encoding). To use this utility function now is trivially easy: In any ASP.NET code that wants to compress its Response output you simply use: protected void Page_Load(object sender, EventArgs e) { WebUtils.GZipEncodePage(); Entry = WebLogFactory.GetEntry(); var entries = Entry.GetLastEntries(App.Configuration.ShowEntryCount, "pk,Title,SafeTitle,Body,Entered,Feedback,Location,ShowTopAd", "TEntries"); if (entries == null) throw new ApplicationException("Couldn't load WebLog Entries: " + Entry.ErrorMessage); this.repEntries.DataSource = entries; this.repEntries.DataBind(); } Here I use an ASP.NET page, but the above WebUtils.GZipEncode() method call will work in any ASP.NET application type including HTTP Handlers. The only requirement is that the filter needs to be applied before any other output is sent to the OutputStream. For example, in my CallbackHandler service implementation by default output over a certain size is GZip encoded. The output that is generated is JSON or XML and if the output is over 5k in size I apply WebUtils.GZipEncode(): if (sbOutput.Length > GZIP_ENCODE_TRESHOLD) WebUtils.GZipEncodePage(); Response.ContentType = ControlResources.STR_JsonContentType; HttpContext.Current.Response.Write(sbOutput.ToString()); Ok, so you probably get the idea: Encoding GZip/Deflate content is pretty easy. Hold on there Hoss –Watch your Caching Or is it? There are a few caveats that you need to watch out for when dealing with GZip content. The fist issue is that you need to deal with the fact that some clients don’t support GZip or Deflate content. Most modern browsers support it, but if you have a programmatic Http client accessing your content GZip/Deflate support is by no means guaranteed. For example, WinInet Http clients don’t support GZip out of the box – it has to be explicitly implemented. Other low level HTTP clients on other platforms too don’t support GZip out of the box. The problem is that your application, your Web Server and Proxy Servers on the Internet might be caching your generated content. If you return content with GZip once and then again without, either caching is not applied or worse the wrong type of content is returned back to the client from a cache or proxy. The result is an unreadable response for *some clients* which is also very hard to debug and fix once in production. You already saw the issue of Proxy servers addressed in the GZipEncodePage() function: // Allow proxy servers to cache encoded and unencoded versions separately Response.AppendHeader("Vary", "Content-Encoding"); This ensures that any Proxy servers also check for the Content-Encoding HTTP Header to cache their content – not just the URL. The same thing applies if you do OutputCaching in your own ASP.NET code. If you generate output for GZip on an OutputCached page the GZipped content will be cached (either by ASP.NET’s cache or in some cases by the IIS Kernel Cache). But what if the next client doesn’t support GZip? She’ll get served a cached GZip page that won’t decode and she’ll get a page full of garbage. Wholly undesirable. To fix this you need to add some custom OutputCache rules by way of the GetVaryByCustom() HttpApplication method in your global_ASAX file: public override string GetVaryByCustomString(HttpContext context, string custom) { // Override Caching for compression if (custom == "GZIP") { string acceptEncoding = HttpContext.Current.Response.Headers["Content-Encoding"]; if (string.IsNullOrEmpty(acceptEncoding)) return ""; else if (acceptEncoding.Contains("gzip")) return "GZIP"; else if (acceptEncoding.Contains("deflate")) return "DEFLATE"; return ""; } return base.GetVaryByCustomString(context, custom); } In a page that use Output caching you then specify: <%@ OutputCache Duration="180" VaryByParam="none" VaryByCustom="GZIP" %> To use that custom rule. It’s all Fun and Games until ASP.NET throws an Error Ok, so you’re up and running with GZip, you have your caching squared away and your pages that you are applying it to are jamming along. Then BOOM, something strange happens and you get a lovely garbled page that look like this: Lovely isn’t it? What’s happened here is that I have WebUtils.GZipEncode() applied to my page, but there’s an error in the page. The error falls back to the ASP.NET error handler and the error handler removes all existing output (good) and removes all the custom HTTP headers I’ve set manually (usually good, but very bad here). Since I applied the Response.Filter (via GZipEncode) the output is now GZip encoded, but ASP.NET has removed my Content-Encoding header, so the browser receives the GZip encoded content without a notification that it is encoded as GZip. The result is binary output. Here’s what Fiddler says about the raw HTTP header output when an error occurs when GZip encoding was applied: HTTP/1.1 500 Internal Server Error Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Sat, 30 Apr 2011 22:21:08 GMT Content-Length: 2138 Connection: close ?`I?%&/m?{J?J??t??` … binary output striped here Notice: no Content-Encoding header and that’s why we’re seeing this garbage. ASP.NET has stripped the Content-Encoding header but left our filter intact. So how do we fix this? In my applications I typically have a global Application_Error handler set up and in this case I’ve been using that. One thing that you can do in the Application_Error handler is explicitly clear out the Response.Filter and set it to null at the top: protected void Application_Error(object sender, EventArgs e) { // Remove any special filtering especially GZip filtering Response.Filter = null; … } And voila I get my Yellow Screen of Death or my custom generated error output back via uncompressed content. BTW, the same is true for Page level errors handled in Page_Error or ASP.NET MVC Error handling methods in a controller. Another and possibly even better solution is to check whether a filter is attached just before the headers are sent to the client as pointed out by Adam Schroeder in the comments: protected void Application_PreSendRequestHeaders() { // ensure that if GZip/Deflate Encoding is applied that headers are set // also works when error occurs if filters are still active HttpResponse response = HttpContext.Current.Response; if (response.Filter is GZipStream && response.Headers["Content-encoding"] != "gzip") response.AppendHeader("Content-encoding", "gzip"); else if (response.Filter is DeflateStream && response.Headers["Content-encoding"] != "deflate") response.AppendHeader("Content-encoding", "deflate"); } This uses the Application_PreSendRequestHeaders() pipeline event to check for compression encoding in a filter and adjusts the content accordingly. This is actually a better solution since this is generic – it’ll work regardless of how the content is cleaned up. For example, an error Response.Redirect() or short error display might get changed and the filter not cleared and this code actually handles that. Sweet, thanks Adam. It’s unfortunate that ASP.NET doesn’t natively clear out Response.Filters when an error occurs just as it clears the Response and Headers. I can’t see where leaving a Filter in place in an error situation would make any sense, but hey - this is what it is and it’s easy enough to fix as long as you know where to look. Riiiight! IIS and GZip I should also mention that IIS 7 includes good support for compression natively. If you can defer encoding to let IIS perform it for you rather than doing it in your code by all means you should do it! Especially any static or semi-dynamic content that can be made static should be using IIS built-in compression. Dynamic caching is also supported but is a bit more tricky to judge in terms of performance and footprint. John Forsyth has a great article on the benefits and drawbacks of IIS 7 compression which gives some detailed performance comparisons and impact reviews. I’ll post another entry next with some more info on IIS compression since information on it seems to be a bit hard to come by. Related Content Built-in GZip/Deflate Compression in IIS 7.x HttpWebRequest and GZip Responses © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET   IIS7  

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  • Need software to convert RAR to ZIP ("store" mode - no compression) * Extract->re-archive changes date/time attributes

    - by Larry78
    I have tried all of the following applications (download.cnet.com - the free ones), and none of them will convert an RAR archive to a ZIP, without compressing the files ("store" mode). 7-ZIP would be fine, too. [The RAR is a "solid" archive with password (I know it), files "stored" - no compression, used WinRAR 3.5.1] PeaZip, 7-Zip, FilZip, TugZip, SimplyZipSE, QuickZip, WinShrink. (A couple of the apps let you try, but the program gives an error - indicating how bad the software is. (Like "unknown header # #.") None of these apps will do the conversion at all. IZArc 4.1 comes the closest. It will convert an RAR to a ZIP, but it compresses the zip. There is a general preference setting to "store" - but it doesn't effect conversions. I don't want to extract the RAR files and re-archive them because I need to preserve the modified/created file attributes. IZArc preserves them, but it compresses the files. WinRAR has the option to convert archives, but I get the error "skipping encryped archive" when I try to convert it. It asks for the password first, and I know it's right because that password opens the archive, and I can read/view all the files in the archive.

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  • Can a page opt out of IIS 7 compression?

    - by Glen Little
    My pages are automatically being compressed by IIS7 with GZIP. That is great... but, for one particular page, I need to stream it to the user, using Response.Flush() when needed. But when the output is being compressed, the IIS server seems to collect all my output until the page is done before compressing and sending it to the client. That nullifies my attempt to Flush the content out to the user. Is there a way that I can have this one page opt out of the compression? One possible option I've determined that if I manually set the content type to one that does not match the IIS configuration at c:\windows\system32\inetsrv\config\applicationhost.config, then IIS will not compress it. Eg. Response.ContentType = "x-text/html". This works okay with IE8, as it falls back to display the HTML. But Firefox will ask the user what to do with the unknown file type. This could work, if there was another Mime Type I could use that browsers would accept as HTML, that is not matched in the applicationhost.config. For reference, these are the mime types that will be compressed: <add mimeType="text/*" enabled="true" /> <add mimeType="message/*" enabled="true" /> <add mimeType="application/x-javascript" enabled="true" /> <add mimeType="application/atom+xml" enabled="true" /> <add mimeType="application/xaml+xml" enabled="true" /> Others options? Are there other options to opt out of compression?

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  • Advantages of SQL Backup Pro

    - by Grant Fritchey
    Getting backups of your databases in place is a fundamental issue for protection of the business. Yes, I said business, not data, not databases, but business. Because of a lack of good, tested, backups, companies have gone completely out of business or suffered traumatic financial loss. That’s just a simple fact (outlined with a few examples here). So you want to get backups right. That’s a big part of why we make Red Gate SQL Backup Pro work the way it does. Yes, you could just use native backups, but you’ll be missing a few advantages that we provide over and above what you get out of the box from Microsoft. Let’s talk about them. Guidance If you’re a hard-core DBA with 20+ years of experience on every version of SQL Server and several other data platforms besides, you may already know what you need in order to get a set of tested backups in place. But, if you’re not, maybe a little help would be a good thing. To set up backups for your servers, we supply a wizard that will step you through the entire process. It will also act to guide you down good paths. For example, if your databases are in Full Recovery, you should set up transaction log backups to run on a regular basis. When you choose a transaction log backup from the Backup Type you’ll see that only those databases that are in Full Recovery will be listed: This makes it very easy to be sure you have a log backup set up for all the databases you should and none of the databases where you won’t be able to. There are other examples of guidance throughout the product. If you have the responsibility of managing backups but very little knowledge or time, we can help you out. Throughout the software you’ll notice little green question marks. You can see two in the screen above and more in each of the screens in other topics below this one. Clicking on these will open a window with additional information about the topic in question which should help to guide you through some of the tougher decisions you may have to make while setting up your backup jobs. Here’s an example: Backup Copies As a part of the wizard you can choose to make a copy of your backup on your network. This process runs as part of the Red Gate SQL Backup engine. It will copy your backup, after completing the backup so it doesn’t cause any additional blocking or resource use within the backup process, to the network location you define. Creating a copy acts as a mechanism of protection for your backups. You can then backup that copy or do other things with it, all without affecting the original backup file. This requires either an additional backup or additional scripting to get it done within the native Microsoft backup engine. Offsite Storage Red Gate offers you the ability to immediately copy your backup to the cloud as a further, off-site, protection of your backups. It’s a service we provide and expose through the Backup wizard. Your backup will complete first, just like with the network backup copy, then an asynchronous process will copy that backup to cloud storage. Again, this is built right into the wizard or even the command line calls to SQL Backup, so it’s part a single process within your system. With native backup you would need to write additional scripts, possibly outside of T-SQL, to make this happen. Before you can use this with your backups you’ll need to do a little setup, but it’s built right into the product to get this done. You’ll be directed to the web site for our hosted storage where you can set up an account. Compression If you have SQL Server 2008 Enterprise, or you’re on SQL Server 2008R2 or greater and you have a Standard or Enterprise license, then you have backup compression. It’s built right in and works well. But, if you need even more compression then you might want to consider Red Gate SQL Backup Pro. We offer four levels of compression within the product. This means you can get a little compression faster, or you can just sacrifice some CPU time and get even more compression. You decide. For just a simple example I backed up AdventureWorks2012 using both methods of compression. The resulting file from native was 53mb. Our file was 33mb. That’s a file that is smaller by 38%, not a small number when we start talking gigabytes. We even provide guidance here to help you determine which level of compression would be right for you and your system: So for this test, if you wanted maximum compression with minimum CPU use you’d probably want to go with Level 2 which gets you almost as much compression as Level 3 but will use fewer resources. And that compression is still better than the native one by 10%. Restore Testing Backups are vital. But, a backup is just a file until you restore it. How do you know that you can restore that backup? Of course, you’ll use CHECKSUM to validate that what was read from disk during the backup process is what gets written to the backup file. You’ll also use VERIFYONLY to check that the backup header and the checksums on the backup file are valid. But, this doesn’t do a complete test of the backup. The only complete test is a restore. So, what you really need is a process that tests your backups. This is something you’ll have to schedule separately from your backups, but we provide a couple of mechanisms to help you out here. First, when you create a backup schedule, all done through our wizard which gives you as much guidance as you get when running backups, you get the option of creating a reminder to create a job to test your restores. You can enable this or disable it as you choose when creating your scheduled backups. Once you’re ready to schedule test restores for your databases, we have a wizard for this as well. After you choose the databases and restores you want to test, all configurable for automation, you get to decide if you’re going to restore to a specified copy or to the original database: If you’re doing your tests on a new server (probably the best choice) you can just overwrite the original database if it’s there. If not, you may want to create a new database each time you test your restores. Another part of validating your backups is ensuring that they can pass consistency checks. So we have DBCC built right into the process. You can even decide how you want DBCC run, which error messages to include, limit or add to the checks being run. With this you could offload some DBCC checks from your production system so that you only run the physical checks on your production box, but run the full check on this backup. That makes backup testing not just a general safety process, but a performance enhancer as well: Finally, assuming the tests pass, you can delete the database, leave it in place, or delete it regardless of the tests passing. All this is automated and scheduled through the SQL Agent job on your servers. Running your databases through this process will ensure that you don’t just have backups, but that you have tested backups. Single Point of Management If you have more than one server to maintain, getting backups setup could be a tedious process. But, with Red Gate SQL Backup Pro you can connect to multiple servers and then manage all your databases and all your servers backups from a single location. You’ll be able to see what is scheduled, what has run successfully and what has failed, all from a single interface without having to connect to different servers. Log Shipping Wizard If you want to set up log shipping as part of a disaster recovery process, it can frequently be a pain to get configured correctly. We supply a wizard that will walk you through every step of the process including setting up alerts so you’ll know should your log shipping fail. Summary You want to get your backups right. As outlined above, Red Gate SQL Backup Pro will absolutely help you there. We supply a number of processes and functionalities above and beyond what you get with SQL Server native. Plus, with our guidance, hints and reminders, you will get your backups set up in a way that protects your business.

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  • OBIEE 11.1.1 - User Interface (UI) Performance Is Slow With Internet Explorer 8

    - by Ahmed A
    The OBIEE 11g UI is performance is slow in IE 8 and faster in Firefox.  For VPN or WAN users, it takes long time to display links on Dashboards via IE 8. Cause is IE 8 generates many HTTP 304 return calls and this caused the 11g UI slower when compared to the Mozilla FireFox browser. To resolve this issue, you can implement HTTP compression and caching. This is a best practice.Why use Web Server Compression / Caching for OBIEE? Bandwidth Savings: Enabling HTTP compression can have a dramatic improvement on the latency of responses. By compressing static files and dynamic application responses, it will significantly reduce the remote (high latency) user response time. Improves request/response latency: Caching makes it possible to suppress the payload of the HTTP reply using the 304 status code.  Minimizing round trips over the Web to re-validate cached items can make a huge difference in browser page load times. This screen shot depicts the flow and where the compression and decompression occurs: Solution: a. How to Enable HTTP Caching / Compression in Oracle HTTP Server (OHS) 11.1.1.x 1. To implement HTTP compression / caching, install and configure Oracle HTTP Server (OHS) 11.1.1.x for the bi_serverN Managed Servers (refer to "OBIEE Enterprise Deployment Guide for Oracle Business Intelligence" document for details). 2. On the OHS machine, open the file HTTP Server configuration file (httpd.conf) for editing. This file is located in the OHS installation directory.For example: ORACLE_HOME/Oracle_WT1/instances/instance1/config/OHS/ohs13. In httpd.conf file, verify that the following directives are included and not commented out: LoadModule expires_module "${ORACLE_HOME}/ohs/modules/mod_expires.soLoadModule deflate_module "${ORACLE_HOME}/ohs/modules/mod_deflate.so 4. Add the following lines in httpd.conf file below the directive LoadModule section and restart the OHS: Note: For the Windows platform, you will need to enclose any paths in double quotes ("), for example:Alias "/analytics ORACLE_HOME/bifoundation/web/app"<Directory "ORACLE_HOME/bifoundation/web/app"> Alias /analytics ORACLE_HOME/bifoundation/web/app#Pls replace the ORACLE_HOME with your actual BI ORACLE_HOME path<Directory ORACLE_HOME/bifoundation/web/app>#We don't generate proper cross server ETags so disable themFileETag noneSetOutputFilter DEFLATE# Don't compress imagesSetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary<FilesMatch "\.(gif|jpeg|png|js|x-javascript|javascript|css)$">#Enable future expiry of static filesExpiresActive onExpiresDefault "access plus 1 week"     #1 week, this will stops the HTTP304 calls i.e. generated by IE 8Header set Cache-Control "max-age=604800"</FilesMatch>DirectoryIndex default.jsp</Directory>#Restrict access to WEB-INF<Location /analytics/WEB-INF>Order Allow,DenyDeny from all</Location> Note: Make sure you replace above placeholder "ORACLE_HOME" to your correct path for BI ORACLE_HOME.For example: my BI Oracle Home path is /Oracle/BIEE11g/Oracle_BI1/bifoundation/web/app Important Notes: Above caching rules restricted to static files found inside the /analytics directory(/web/app). This approach is safer instead of setting static file caching globally. In some customer environments you may not get 100% performance gains in IE 8.0 browser. So in that case you need to extend caching rules to other directories with static files content. If OHS is installed on separate dedicated machine, make sure static files in your BI ORACLE_HOME (../Oracle_BI1/bifoundation/web/app) is accessible to the OHS instance. The following screen shot summarizes the before and after results and improvements after enabling compression and caching:

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  • Awesome new feature for HCC

    - by Steve Tunstall
    I've talked about HCC (Hybrid Columnar Compression) before. This is Oracle's built-in compression feature, free of charge in 11Gr2, that allows a CRAZY amount of compression on historical data inside an Oracle database. It only works if the database is being stored in a ZFSSA, Exadata or Axiom. You can read all about it in this whitepaper, which shows the huge value of HCC when used with the ZFSSA. http://www.oracle.com/technetwork/articles/servers-storage-admin/perf-hybrid-columnar-compression-1689701.html Now, even better, Oracle has announced  a great new feature in Oracle 12c called "Automatic Data Optimization". This allows one to setup HCC to AUTOMATICALLY compress data AS IT AGES.  So this is now ILM all built into the Oracle database. It's free for crying out loud. It just needs to be sitting on Oracle storage, such as the ZFSSA, Exadata or Axiom.  Read about ADO here: http://www.oracle.com/technetwork/database/automatic-data-optimization-wp-12c-1896120.pdf?ssSourceSiteId=ocomen

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  • Adoption of Exadata - Gartner research note

    - by Javier Puerta
    Independent research note by Gartner acknowledges Oracle Exadata Database Machine has achieved significant early adoption and acceptance of its database appliance value proposition. Analyst Merv Adrian looks at some of the main issues that IT professionals have solved as they assess or deploy the Oracle Exadata solution, including: OLTP and DSS workload support workload consolidation increasing performance and scalability demands data compression improvements  Gartner reports clients using Oracle Exadata experienced the following: report significant performance improvements substantial amounts of cache memory which greatly improves processing speed Oracle Advanced Compression providing 2-4X data compression delivering significant reductions in storage requirements and driving shorter times for backup operations Tables compressed with Oracle Advanced Compression automatically recompress as data is added/updated. One client specifically reported consolidating more than 400 applications onto the Oracle Exadata platform Read the full Gartner note

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  • SQLIO Writes

    - by Grant Fritchey
    SQLIO is a fantastic utility for testing the abilities of the disks in your system. It has a very unfortunate name though, since it's not really a SQL Server testing utility at all. It really is a disk utility. They ought to call it DiskIO because they'd get more people using I think. Anyway, branding is not the point of this blog post. Writes are the point of this blog post. SQLIO works by slamming your disk. It performs as mean reads as it can or it performs as many writes as it can depending on how you've configured your tests. There are much smarter people than me who will get into all the various types of tests you should run. I'd suggest reading a bit of what Jonathan Kehayias (blog|twitter) has to say or wade into Denny Cherry's (blog|twitter) work. They're going to do a better job than I can describing all the benefits and mechanisms around using this excellent piece of software. My concerns are very focused. I needed to set up a series of tests to see how well our product SQL Storage Compress worked. I wanted to know the effects it would have on a system, the disk for sure, but also memory and CPU. How to stress the system? SQLIO of course. But when I set it up and ran it, following the documentation that comes with it, I was seeing better than 99% compression on the files. Don't get me wrong. Our product is magnificent, wonderful, all things great and beautiful, gets you coffee in the morning and is made mostly from bacon. But 99% compression. No, it's not that good. So what's up? Well, it's the configuration. The default mechanism is to load up a file, something large that will overwhelm your disk cache. You're instructed to load the file with a character 0x0. I never got a computer science degree. I went to film school. Because of this, I didn't memorize ASCII tables so when I saw this, I thought it was zero's or something. Nope. It's NULL. That's right, you're making a very large file, but you're filling it with NULL values. That's actually ok when all you're testing is the disk sub-system. But, when you want to test a compression and decompression, that can be an issue. I got around this fairly quickly. Instead of generating a file filled with NULL values, I just copied a database file for my tests. And to test it with SQL Storage Compress, I used a database file that had already been run through compression (about 40% compression on that file if you're interested). Now the reads were taken care of. I am seeing very realistic performance from decompressing the information for reads through SQLIO. But what about writes? Well, the issue is, what does SQLIO write? I don't have access to the code. But I do have access to the results. I did two different tests, just to be sure of what I was seeing. First test, use the .DAT file as described in the documentation. I opened the .DAT file after I was done with SQLIO, using WordPad. Guess what? It's a giant file full of air. SQLIO writes NULL values. What does that do to compression? I did the test again on a copy of an uncompressed database file. Then I ran the original and the SQLIO modified copy through ZIP to see what happened. I got better than 99% compression out of the SQLIO modified file (original file of 624,896kb went to 275,871kb compressed, after SQLIO it went to 608kb compressed). So, what does SQLIO write? It writes air. If you're trying to test it with compression or maybe some other type of file storage mechanism like dedupe, you need to know this because your tests really won't be valid. Should I find some other mechanism for testing? Yeah, if all I'm interested in is establishing performance to my own satisfaction, yes. But, I want to be able to compare my results with other people's results and we all need to be using the same tool in order for that to happen. SQLIO is the common mechanism that most people I know use to establish disk performance behavior. It'd be better if we could get SQLIO to do writes in some other fashion. Oh, and before I go, I get to brag a bit. Measuring IOPS, SQL Storage Compress outperforms my disk alone by about 30%.

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  • 7-Zip

    An open source compression utility that supports the new 7z format with LZMA compression and much more

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  • running more than one command line commands inside for loop

    - by klijo
    i have a folder containing images and i want to determine its Compression method used. So i would loop through the folder and do a grep Compression like this and note i have installed grep for windows for %f in (*.jpg) do identify -verbose "%f" | grep Compression >> info.txt However i need to write the file name and compression technique used so i modified the above command for %f in (*.jpg) do identify -verbose "%f" | grep Compression & echo "%f" & echo: >> info.txt But the problem is that i get a blank txt file. Could someone pleas help me.

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  • Using Excel VBA to Create SQL Tables

    - by user307655
    Hi All, I am trying to use Excel VBA to automate the creation of a SQL table in an existing SQL Database. I have come across the following code on this side. Private Sub CreateDatabaseFromExcel() Dim dbConnectStr As String Dim Catalog As Object Dim cnt As ADODB.Connection Dim dbPath As String Dim tblName As String 'Set database name in the Excel Sheet dbPath = ActiveSheet.Range("B1").Value 'Database Name tblName = ActiveSheet.Range("B2").Value 'Table Name dbConnectStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & dbPath & ";" 'Create new database using name entered in Excel Cell ("B1") Set Catalog = CreateObject("ADOX.Catalog") Catalog.Create dbConnectStr Set Catalog = Nothing 'Connect to database and insert a new table Set cnt = New ADODB.Connection With cnt .Open dbConnectStr .Execute "CREATE TABLE tblName ([BankName] text(50) WITH Compression, " & _ "[RTNumber] text(9) WITH Compression, " & _ "[AccountNumber] text(10) WITH Compression, " & _ "[Address] text(150) WITH Compression, " & _ "[City] text(50) WITH Compression, " & _ "[ProvinceState] text(2) WITH Compression, " & _ "[Postal] text(6) WITH Compression, " & _ "[AccountAmount] decimal(6))" End With Set cnt = Nothing End Sub However i can't successfully get it to work? What I am trying to do is actually use Excel to create a table not a database? The database already exists. I would just like to create a new table. The name of the table will be referenced from cell A1 in Sheet 1. Can somebody please help. Thanks Regards Gerard

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