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• Permutations distinct under given symmetry (Mathematica 8 group theory)

  - by Yaroslav Bulatov

  Given a list of integers like {2,1,1,0} I'd like to list all permutations of that list that are not equivalent under given group. For instance, using symmetry of the square, the result would be {{2, 1, 1, 0}, {2, 1, 0, 1}}. Approach below (Mathematica 8) generates all permutations, then weeds out the equivalent ones. I can't use it because I can't afford to generate all permutations, is there a more efficient way? Update: actually, the bottleneck is in DeleteCases. The following list {2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 0, 0, 0} has about a million permutations and takes 0.1 seconds to compute. Apparently there are supposed to be 1292 orderings after removing symmetries, but my approach doesn't finish in 10 minutes removeEquivalent[{}] := {}; removeEquivalent[list_] := ( Sow[First[list]]; equivalents = Permute[First[list], #] & /@ GroupElements[group]; DeleteCases[list, Alternatives @@ equivalents] ); nonequivalentPermutations[list_] := ( reaped = Reap@FixedPoint[removeEquivalent, Permutations@list]; reaped[[2, 1]] ); group = DihedralGroup[4]; nonequivalentPermutations[{2, 1, 1, 0}]

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• compact XSLT code to drop N number of tags if all are null.

  - by infant programmer

  This is my input xml: <root> <node1/> <node2/> <node3/> <node4/> <othertags/> </root> The output must be: <root> <othertags/> </root> if any of the 4 nodes isn't null then none of the tags must be dropped. example: <root> <node1/> <node2/> <node3/> <node4>sample_text</node4> <othertags/> </root> Then the output must be same as input xml. <root> <node1/> <node2/> <node3/> <node4>sample_text</node4> <othertags/> </root> This is the XSL code I have designed :: <xsl:template match="@*|node()"> <xsl:copy> <xsl:apply-templates select="@*|node()"/> </xsl:copy> </xsl:template> <xsl:template match="/root/node1[.='' and ../node2/.='' and ../node3/.='' and ../node4/.=''] |/root/node2[.='' and ../node1/.='' and ../node3/.='' and ../node4/.=''] |/root/node3[.='' and ../node1/.='' and ../node2/.='' and ../node4/.=''] |/root/node4[.='' and ../node1/.='' and ../node2/.='' and ../node3/.='']"/> As you can see the code requires more effort and becomes more bulky as the number of nodes increase. Is there any alternative way to overcome this bottleneck?

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• Ruby integer to string key

  - by Gene

  A system I'm building needs to convert non-negative Ruby integers into shortest-possible UTF-8 string values. The only requirement on the strings is that their lexicographic order be identical to the natural order on integers. What's the best Ruby way to do this? We can assume the integers are 32 bits and the sign bit is 0. This is successful: (i >> 24).chr + ((i >> 16) & 0xff).chr + ((i >> 8) & 0xff).chr + (i & 0xff).chr But it appears to be 1) garbage-intense and 2) ugly. I've also looked at pack solutions, but these don't seem portable due to byte order. FWIW, the application is Redis hash field names. Building keys may be a performance bottleneck, but probably not. This question is mostly about the "Ruby way".

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• I just discovered why all ASP.Net websites are slow, and I am trying to work out what to do about it

  - by James

  I just discovered that every request in an ASP.Net web application gets a Session lock at the begging of a request, and then releases it at the end of the request!!! I mean, WTF Microsoft! In case the implication is lost on you, as it was from me at first, this basically means the following: Anytime an ASP.Net webpage is taking a long time to load (maybe due to a slow database call or whatever), and the user decides they want to navigate to a different page because they are tired of waiting, THEY CANT! The ASP.Net session lock forces the new page request to wait until the original request has finished its painfully slow load. Arrrgh. Anytime an UpdatePanel is loading slowly, and the user decides to navigate to a different page before the UpdadePanel has finished updating... THEY CANT! The ASP.Net session lock forces the new page request to wait until the original request has finished its painfully slow load. Double Arrrgh! So what are the options? So far I have come up with: Implement a Custom SessionStateDataStore, which ASP.Net supports. I haven't found too many out there to copy, and it seems kind of high risk and easy to mess up. Keep track of all requests in progress, and if a request comes in from the same user, cancel the original request. Seems kind of extreme, but it would work (I think) Don't user Session! When I need some kind of state for the user, I could just user Cache instead, and key items on the authenticated user's name, or some such thing. Again seems kind of extreme I really can't believe that the ASP.Net Microsoft team would have left such a huge performance bottleneck in the framework at version 4.0! Am I missing something obvious? How hard would it be to use a ThreadSafe collection for the Session? Arrrrghhhhhh. Any advice much appreciated.

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• Performance of stored proc when updating columns selectively based on parameters?

  - by kprobst

  I'm trying to figure out if this is relatively well-performing T-SQL (this is SQL Server 2008). I need to create a stored procedure that updates a table. The proc accepts as many parameters as there are columns in the table, and with the exception of the PK column, they all default to NULL. The body of the procedure looks like this: CREATE PROCEDURE proc_repo_update @object_id bigint ,@object_name varchar(50) = NULL ,@object_type char(2) = NULL ,@object_weight int = NULL ,@owner_id int = NULL -- ...etc AS BEGIN update object_repo set object_name = ISNULL(@object_name, object_name) ,object_type = ISNULL(@object_type, object_type) ,object_weight = ISNULL(@object_weight, object_weight) ,owner_id = ISNULL(@owner_id, owner_id) -- ...etc where object_id = @object_id return @@ROWCOUNT END So basically: Update a column only if its corresponding parameter was provided, and leave the rest alone. This works well enough, but as the ISNULL call will return the value of the column if the received parameter was null, will SQL Server optimize this somehow? This might be a performance bottleneck on the application where the table might be updated heavily (insertion will be uncommon so the performance there is not a problem). So I'm trying to figure out what's the best way to do this. Is there a way to condition the column expressions with something like CASE WHEN or something? The table will be indexed up the wazoo as well for read performance. Is this the best approach? My alternative at this point is to create the UPDATE expression in code (e.g. inline SQL) and execute it against the server. This would solve my doubts about performance, but I'd rather leave this in a stored proc if possible.

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• PHP, MySQL, Memcache / Ajax Scaling Problem

  - by Jeff Andersen

  I'm building a ajax tic tac toe game in PHP/MySQL. The premise of the game is to be able to share a url like mygame.com/123 with your friends and you play multiple simultaneous games. The way I have it set up is that a file (reload.php) is being called every 3 seconds while the user is viewing their game board space. This reload.php builds their game boards and the output (html) replaces their current game board (thus showing games in which it is their turn) Initially I built it entirely with PHP/MySQL and had zero caching. A friend gave me a suggestion to try doing all of the temporary/quick read information through memcache (storing moves, and ID matchups) and then building the game boards from this information. My issue is that, both solutions encounter a wall when there is roughly 30-40 active users with roughly 40-50 games running. It is running on a VPS from VPS.net with 2 nodes. (Dedicated CPU: 1.2GHz, RAM: 752MB) Each call to reload.php peforms 3 selects and 2 insert queries. The size of the data being pulled is negligible. The same actions happen on index.php to build the boards for the initial visit. Now that the backstory is done, my question is: Would there be a bottleneck in that each user is polling the same file every 3 seconds to rebuild their gameboards, and that all users are sitting on index.php from which the AJAX calls are made within the HTML. If so, is it possible to spread the users' calls out over a set of files designated to building the game boards (eg. reload1.php 2, 3 etc) and direct users to the appropriate file. Would this relieve the pressure? A long winded explanation; however, I didn't have anywhere else to ask. Thanks very much for any insight.

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• Passing C++ object to C++ code through Python?

  - by cornail

  Hi all, I have written some physics simulation code in C++ and parsing the input text files is a bottleneck of it. As one of the input parameters, the user has to specify a math function which will be evaluated many times at run-time. The C++ code has some pre-defined function classes for this (they are actually quite complex on the math side) and some limited parsing capability but I am not satisfied with this construction at all. What I need is that both the algorithm and the function evaluation remain speedy, so it is advantageous to keep them both as compiled code (and preferrably, the math functions as C++ function objects). However I thought of glueing the whole simulation together with Python: the user could specify the input parameters in a Python script, while also implementing storage, visualization of the results (matplotlib) and GUI, too, in Python. I know that most of the time, exposing C++ classes can be done, e.g. with SWIG but I still have a question concerning the parsing of the user defined math function in Python: Is it possible to somehow to construct a C++ function object in Python and pass it to the C++ algorithm? E.g. when I call f = WrappedCPPGaussianFunctionClass(sigma=0.5) WrappedCPPAlgorithm(f) in Python, it would return a pointer to a C++ object which would then be passed to a C++ routine requiring such a pointer, or something similar... (don't ask me about memory management in this case, though :S) The point is that no callback should be made to Python code in the algorithm. Later I would like to extend this example to also do some simple expression parsing on the Python side, such as sum or product of functions, and return some compound, parse-tree like C++ object but let's stay at the basics for now. Sorry for the long post and thx for the suggestions in advance.

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• What is the fastest (to access) struct-like object in Python?

  - by DNS

  I'm optimizing some code whose main bottleneck is running through and accessing a very large list of struct-like objects. Currently I'm using namedtuples, for readability. But some quick benchmarking using 'timeit' shows that this is really the wrong way to go where performance is a factor: Named tuple with a, b, c: >>> timeit("z = a.c", "from __main__ import a") 0.38655471766332994 Class using __slots__, with a, b, c: >>> timeit("z = b.c", "from __main__ import b") 0.14527461047146062 Dictionary with keys a, b, c: >>> timeit("z = c['c']", "from __main__ import c") 0.11588272541098377 Tuple with three values, using a constant key: >>> timeit("z = d[2]", "from __main__ import d") 0.11106188992948773 List with three values, using a constant key: >>> timeit("z = e[2]", "from __main__ import e") 0.086038238242508669 Tuple with three values, using a local key: >>> timeit("z = d[key]", "from __main__ import d, key") 0.11187358437882722 List with three values, using a local key: >>> timeit("z = e[key]", "from __main__ import e, key") 0.088604143037173344 First of all, is there anything about these little timeit tests that would render them invalid? I ran each several times, to make sure no random system event had thrown them off, and the results were almost identical. It would appear that dictionaries offer the best balance between performance and readability, with classes coming in second. This is unfortunate, since, for my purposes, I also need the object to be sequence-like; hence my choice of namedtuple. Lists are substantially faster, but constant keys are unmaintainable; I'd have to create a bunch of index-constants, i.e. KEY_1 = 1, KEY_2 = 2, etc. which is also not ideal. Am I stuck with these choices, or is there an alternative that I've missed?

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• A basic load test question

  - by user236131

  I have a very basic load test question. I am running a load test using VSTS 2008 and I have test rig with controller + 10 agents. This load test is against a SharePoint farm I have. My goal of the load test is to find out the resource utilization on web+app+db tiers of my farm for any given load scenario. An example of a load scenario is Usage profile: Average collaboration (as defined by SCCP) User Load: 500 (using step load pattern=a step of 50 every 2 mins and a warm up time of 2mins for every step) Think time: 0 Load duration: 8hrs Now, the question is: Is it fair to expect that metrics like Requests/sec, %processor time on web front end / App / DB, Test/sec, and etc become flat or enter a steady state at one point in time during the load test. Like I said, the goal is not to create a bottleneck but to only measure the utilization of resources by the above load profile. I am asking this question because I see something different. At one point in the load test, requests/sec becomes more or less flat. But processor utilization on the web/DB servers keeps increasing. After digging through the data a bit, I see that "tests running" counter also steadily increased over time. So, if I run the load test for more than 8hrs, %processor may go up further. This way, I don't know what to consider as the load excreted by the load profile. What does this "tests running" counter really signify? How is this different from tests/sec? Another question is: how can I find out why "tests running" counter shows an increase overtime? Thanks for your time

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• How to optimize this simple function which translates input bits into words?

  - by psihodelia

  I have written a function which reads an input buffer of bytes and produces an output buffer of words where every word can be either 0x0081 for each ON bit of the input buffer or 0x007F for each OFF bit. The length of the input buffer is given. Both arrays have enough physical place. I also have about 2Kbyte free RAM which I can use for lookup tables or so. Now, I found that this function is my bottleneck in a real time application. It will be called very frequently. Can you please suggest a way how to optimize this function? I see one possibility could be to use only one buffer and do in-place substitution. void inline BitsToWords(int8 *pc_BufIn, int16 *pw_BufOut, int32 BufInLen) { int32 i,j,z=0; for(i=0; i<BufInLen; i++) { for(j=0; j<8; j++, z++) { pw_BufOut[z] = ( ((pc_BufIn[i] >> (7-j))&0x01) == 1? 0x0081: 0x007f ); } } } Please do not offer any compiler specific or CPU/Hardware specific optimization, because it is a multi-platform project.

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• In sync query calls, one query causing other query to run slower. Why?

  - by Irchi

  Sorry for the long question, but I think this is an interesting situation and I couldn't find any explanations for it: I was involved in optimization of an application that performed a large number of sequential SELECT and INSERT statements on a single dedicated SQL Server database. The process needs to INSERT a large number of records into a table, but for each of them there should be some value mappings, which performed using SELECT statements on another table in the same database. For a specific execution, it took 90 minutes to run. I used a profiler (JProfiler - the application is Java-based) to determine how much time does each part of the application take. It yields that 60% of the time was spent on INSERT method calls, and almost 20% on SELECT calls (the rest distributed in other parts). After some trials, I came to this situation: I commented out the INSERT query that took 60% of the time. I was expecting for the total run time to be around 35 minutes, as I have removed 60% of the 90 minutes. But the whole process took the same 90 minutes (doing only SELECTs and nothing else), but each SELECT took longer this time! Everything was running sync, there were no async calls. And there was only one single thread of execution. SELECT and INSERT queries are very simple, and don't have anything special, and they are on different tables, but on the same DB. I tested with both the DB on the application machine, and on a remote network machine. I can't think of any explanation for this, as the Profiler (Application profiler, not SQL Profiler) reported the changes in the method call times, and by removing INSERT statements SELECT statements took longer to run. Can anyone give me some kind of explanation of what could have happened? (there can't be cache / query optimization stuff, because the queries were run in sync, and in a single thread, and it was far from affecting the cache this much) I should note that the bottleneck of the speed was in SQL server, using most of the CPU time.

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• SQL SERVER – Introduction to Wait Stats and Wait Types – Wait Type – Day 1 of 28

  - by pinaldave

  I have been working a lot on Wait Stats and Wait Types recently. Last Year, I requested blog readers to send me their respective server’s wait stats. I appreciate their kind response as I have received  Wait stats from my readers. I took each of the results and carefully analyzed them. I provided necessary feedback to the person who sent me his wait stats and wait types. Based on the feedbacks I got, many of the readers have tuned their server. After a while I got further feedbacks on my recommendations and again, I collected wait stats. I recorded the wait stats and my recommendations and did further research. At some point at time, there were more than 10 different round trips of the recommendations and suggestions. Finally, after six month of working my hands on performance tuning, I have collected some real world wisdom because of this. Now I plan to share my findings with all of you over here. Before anything else, please note that all of these are based on my personal observations and opinions. They may or may not match the theory available at other places. Some of the suggestions may not match your situation. Remember, every server is different and consequently, there is more than one solution to a particular problem. However, this series is written with kept wait stats in mind. While I was working on various performance tuning consultations, I did many more things than just tuning wait stats. Today we will discuss how to capture the wait stats. I use the script diagnostic script created by my friend and SQL Server Expert Glenn Berry to collect wait stats. Here is the script to collect the wait stats: -- Isolate top waits for server instance since last restart or statistics clear WITH Waits AS (SELECT wait_type, wait_time_ms / 1000. AS wait_time_s, 100. * wait_time_ms / SUM(wait_time_ms) OVER() AS pct, ROW_NUMBER() OVER(ORDER BY wait_time_ms DESC) AS rn FROM sys.dm_os_wait_stats WHERE wait_type NOT IN ('CLR_SEMAPHORE','LAZYWRITER_SLEEP','RESOURCE_QUEUE','SLEEP_TASK' ,'SLEEP_SYSTEMTASK','SQLTRACE_BUFFER_FLUSH','WAITFOR', 'LOGMGR_QUEUE','CHECKPOINT_QUEUE' ,'REQUEST_FOR_DEADLOCK_SEARCH','XE_TIMER_EVENT','BROKER_TO_FLUSH','BROKER_TASK_STOP','CLR_MANUAL_EVENT' ,'CLR_AUTO_EVENT','DISPATCHER_QUEUE_SEMAPHORE', 'FT_IFTS_SCHEDULER_IDLE_WAIT' ,'XE_DISPATCHER_WAIT', 'XE_DISPATCHER_JOIN', 'SQLTRACE_INCREMENTAL_FLUSH_SLEEP')) SELECT W1.wait_type, CAST(W1.wait_time_s AS DECIMAL(12, 2)) AS wait_time_s, CAST(W1.pct AS DECIMAL(12, 2)) AS pct, CAST(SUM(W2.pct) AS DECIMAL(12, 2)) AS running_pct FROM Waits AS W1 INNER JOIN Waits AS W2 ON W2.rn <= W1.rn GROUP BY W1.rn, W1.wait_type, W1.wait_time_s, W1.pct HAVING SUM(W2.pct) - W1.pct < 99 OPTION (RECOMPILE); -- percentage threshold GO This script uses Dynamic Management View sys.dm_os_wait_stats to collect the wait stats. It omits the system-related wait stats which are not useful to diagnose performance-related bottleneck. Additionally, not OPTION (RECOMPILE) at the end of the DMV will ensure that every time the query runs, it retrieves new data and not the cached data. This dynamic management view collects all the information since the time when the SQL Server services have been restarted. You can also manually clear the wait stats using the following command: DBCC SQLPERF('sys.dm_os_wait_stats', CLEAR); Once the wait stats are collected, we can start analysis them and try to see what is causing any particular wait stats to achieve higher percentages than the others. Many waits stats are related to one another. When the CPU pressure is high, all the CPU-related wait stats show up on top. But when that is fixed, all the wait stats related to the CPU start showing reasonable percentages. It is difficult to have a sure solution, but there are good indications and good suggestions on how to solve this. I will keep this blog post updated as I will post more details about wait stats and how I reduce them. The reference to Book On Line is over here. Of course, I have selected February to run this Wait Stats series. I am already cheating by having the smallest month to run this series. :) Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQLAuthority News – Guest Post – Performance Counters Gathering using Powershell

  - by pinaldave

  Laerte Junior Laerte Junior has previously helped me personally to resolve the issue with Powershell installation on my computer. He did awesome job to help. He has send this another wonderful article regarding performance counter for readers of this blog. I really liked it and I expect all of you who are Powershell geeks, you will like the same as well. As a good DBA, you know that our social life is restricted to a few movies over the year and, when possible, a pizza in a restaurant next to your company’s place, of course. So what we have to do is to create methods through which we can facilitate our daily processes to go home early, and eventually have a nice time with our family (and not sleeping on the couch). As a consultant or fixed employee, one of our daily tasks is to monitor performance counters using Perfmom. To be honest, IDE is getting more complicated. To deal with this, I thought a solution using Powershell. Yes, with some lines of Powershell, you can configure which counters to use. And with one more line, you can already start collecting data. Let’s see one scenario: You are a consultant who has several clients and has just closed another project in troubleshooting an SQL Server environment. You are to use Perfmom to collect data from the server and you already have its XML configuration files made with the counters that you will be using- a file for memory bottleneck f, one for CPU, etc. With one Powershell command line for each XML file, you start collecting. The output of such a TXT file collection is set to up in an SQL Server. With two lines of command for each XML, you make the whole process of data collection. Creating an XML configuration File to Memory Counters: Get-PerfCounterCategory -CategoryName "Memory" | Get-PerfCounterInstance  | Get-PerfCounterCounters |Save-ConfigPerfCounter -PathConfigFile "c:\temp\ConfigfileMemory.xml" -newfile Creating an XML Configuration File to Buffer Manager, counters Page lookups/sec, Page reads/sec, Page writes/sec, Page life expectancy: Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters -CounterName "Page*" | Save-ConfigPerfCounter -PathConfigFile "c:\temp\BufferManager.xml" –NewFile Then you start the collection: Set-CollectPerfCounter -DateTimeStart "05/24/2010 08:00:00" -DateTimeEnd "05/24/2010 22:00:00" -Interval 10 -PathConfigFile c:\temp\ConfigfileMemory.xml -PathOutputFile c:\temp\ConfigfileMemory.txt To let the Buffer Manager collect, you need one more counters, including the Buffer cache hit ratio. Just add a new counter to BufferManager.xml, omitting the new file parameter Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters -CounterName "Buffer cache hit ratio" | Save-ConfigPerfCounter -PathConfigFile "c:\temp\BufferManager.xml" And start the collection: Set-CollectPerfCounter -DateTimeStart "05/24/2010 08:00:00" -DateTimeEnd "05/24/2010 22:00:00" -Interval 10 -PathConfigFile c:\temp\BufferManager.xml -PathOutputFile c:\temp\BufferManager.txt You do not know which counters are in the Category Buffer Manager? Simple! Get-PerfCounterCategory -CategoryName "SQLServer:Buffer Manager" | Get-PerfCounterInstance | Get-PerfCounterCounters Let’s see one output file as shown below. It is ready to bulk insert into the SQL Server. As you can see, Powershell makes this process incredibly easy and fast. Do you want to see more examples? Visit my blog at Shell Your Experience You can find more about Laerte Junior over here: www.laertejuniordba.spaces.live.com www.simple-talk.com/author/laerte-junior www.twitter.com/laertejuniordba SQL Server Powershell Extension Team: http://sqlpsx.codeplex.com/ Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: SQL, SQL Add-On, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology Tagged: Powershell

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• You Might Be a DBA

  - by BuckWoody

  With all apologies to Jeff Foxworthy, I was up late Friday night on a holiday weekend (which translated into T-SQL becomes “Maintenance Window”) and I got bored in between the two or three minutes I had between clicks. So I started a “Twitter” meme – and it just took off. I haven’t cleaned these up much, but here, in author order as of Saturday the 29th of May is the list “You might be a DBA” from around the Twitterverse: buckwoody Your two main enemies are developers and SAN admins #youmightbeaDBA  buckwoody People can use Access as a cross or garlic on you #youmightbeaDBA  buckwoody You always plan an exit strategy, even when entering a McDonald's #youmightbeaDBA  buckwoody You can't explain to your family what you really do for a living #youmightbeaDBA  buckwoody You have at least one set of scripts you won't share #youmightbeaDBA  buckwoody You have an opinion on the best code-beautifier #youmightbeaDBA  buckwoody You have children older than the rest of your team #youmightbeaDBA  buckwoody You and the Oracle DBA would kill each other, but you'll happily fight off a developer together first #youmightbeaDBA  buckwoody You've threatened to quit if they give anyone the sa password on production #youmightbeaDBA  buckwoody You've sent a vendor suggestions on improving their database design or code (and been ignored) #youmightbeaDBA  buckwoody You've sent a vendor suggestions on improving their database design or code (and been ignored) #youmightbeaDBA  buckwoody You have an opinion on the best code-beautifier #youmightbeaDBA  buckwoody You have at least one set of scripts you won't share #youmightbeaDBA  buckwoody You refer to co-workers as "carbon-units" #youmightbeaDBA  buckwoody Being paranoid is on your resume at the top #youmightbeaDBA  buckwoody Everyone comes to your cube to find the MSDN DVD's #youmightbeaDBA  buckwoody You always plan an exit strategy, even when entering a McDonald's #youmightbeaDBA  buckwoody You've worn down developers to get your way by explaining normalization levels #youmightbeaDBA  buckwoody You refer to clothes as "Data Abstractions" #youmightbeaDBA  buckwoody Users pester you to be able to put data in a database, then they pester you to take it out and put it in Excel #youmightbeaDBA  buckwoody Others try to de-duplicate data, you try to copy it to more than three locations #youmightbeaDBA  buckwoody You have at least one DLT tape in the trunk of your car #youmightbeaDBA  buckwoody You use twitter and facebook to talk with colleagues because there's no one else in your company that does what you do #youmightbeaDBA  buckwoody Your spouse knows what "ETL" means #youmightbeaDBA  buckwoody You've referred to yourself as the "Data Janitor" #youmightbeaDBA  buckwoody You don't have positive connotations of the word "upgrade" #youmightbeaDBA  buckwoody You get your coffee before you check your servers, because you know you won't get any if you don't #youmightbeaDBA  buckwoody You always come to work through the back door so no one hijacks you on the way to your cube #youmightbeaDBA  buckwoody You check your server logs before you check your e-mail in the morning so you can reply "Yeah, I already fixed that." #youmightbeaDBA  buckwoody You have more conference badges than clean socks #youmightbeaDBA  buckwoody Your coffee mug says "It depends" #youmightbeaDBA  buckwoody You can convince a boss that you need 16GB of RAM in your laptop #youmightbeaDBA  buckwoody You've used ebay to find production equipment #youmightbeaDBA  buckwoody You pad all project timelines by 2X, and you still miss them #youmightbeaDBA  buckwoody You know when your company is acquiring another even before the CFO #youmightbeaDBA  buckwoody You pad all project timelines by 2X, and you still miss them #youmightbeaDBA  buckwoody You call aspirin "work vitamins" #youmightbeaDBA  buckwoody You get the same amount of sleep even after you have a child #youmightbeaDBA  buckwoody You obsess about performance metrics from over one year ago #youmightbeaDBA  buckwoody The first thing you buy after the database software is aftermarket tools to manage the database software #youmightbeaDBA  buckwoody You've tried to convince someone else to become a DBA #youmightbeaDBA  buckwoody You use twitter and facebook to talk with colleagues because there's no one else in your company that does what you do #youmightbeaDBA  buckwoody You only know other DBA's by their Tweet Handle #youmightbeaDBA  buckwoody You've explained the difference between 32 and 64-bit to more than one manager in terms they can understand, using puppets #youmightbeaDBA  buckwoody Your two main enemies are developers and SAN admins #youmightbeaDBA  buckwoody You've driven to the Datacenter to install SQL Server because "you don't trust those NOC admins" #youmightbeaDBA  buckwoody You pay more for faster Internet connections than cable at home so you don't have to drive in #youmightbeaDBA  buckwoody You call texting a "queuing system" #youmightbeaDBA  buckwoody You know that if someone can read Perl, they manage an Oracle system #youmightbeaDBA  buckwoody You have an e-mail rule for backup notifications #youmightbeaDBA  buckwoody Your food pyramid includes coffee, salt and fat #youmightbeaDBA  buckwoody You wish everything had a graphical query plan #youmightbeaDBA  buckwoody You refactor your e-mails #youmightbeaDBA  buckwoody You've gotten more help from twitter and facebook than all your years in college #youmightbeaDBA  buckwoody You would pay money for a license plate that has the letters S-Q-L together #youmightbeaDBA  buckwoody You have actually considered making a RAID array from thumb drives #youmightbeaDBA  buckwoody Everything on your laptop is installed from your MSDN subscription #youmightbeaDBA  buckwoody You've written blog posts on technology you've never actually implemented in production #youmightbeaDBA  buckwoody Everything on your laptop is installed from your MSDN subscription #youmightbeaDBA  buckwoody @MidnightDBA Click the #youmightbeaDBA tag. I've had WAY too much coffee today.  buckwoody There is no other position that is 1-deep except you and the CEO #youmightbeaDBA  buckwoody When you watch "The Office" you call it "OJT" #youmightbeaDBA  buckwoody You would pay money for a license plate that has the letters S-Q-L together #youmightbeaDBA  buckwoody Your blog would make a "best practices" or "worst practices" book #youmightbeaDBA  buckwoody You have actually considered making a RAID array from thumb drives #youmightbeaDBA  buckwoody The first thing you install on your netbook is SSMS #youmightbeaDBA  buckwoody Everything on your laptop is installed from your MSDN subscription #youmightbeaDBA  buckwoody Your watch is set to UTC because it's just easier #youmightbeaDBA  buckwoody You make plenty of money, but you're excited to get a $2.00 squeeze-ball from Quest and Redgate #youmightbeaDBA  buckwoody You make plenty of money, but you're excited to get a $2.00 squeeze-ball from Quest and Redgate #youmightbeaDBA  buckwoody You think data can be represented as something OTHER than XML #youmightbeaDBA  buckwoody You tell people that you made a database query go faster, and expect them to be happy for you #youmightbeaDBA  buckwoody You take the word "NoSQL" as a personal attack #youmightbeaDBA  buckwoody People can use Access as a cross or garlic on you #youmightbeaDBA  buckwoody * == bad #youmightbeaDBA  buckwoody * == bad #youmightbeaDBA  buckwoody There are just as many females in your technical field as males #youmightbeaDBA  buckwoody People can use Access as a cross or garlic on you #youmightbeaDBA  buckwoody You've gotten more help from twitter and facebook than all your years in college #youmightbeaDBA  buckwoody You think that something OTHER than the database might be the performance bottleneck #youmightbeaDBA  buckwoody You refer to time as a "Clustered Index" #youmightbeaDBA  buckwoody You know why "user" refers to both business people and crack addicts #youmightbeaDBA  buckwoody You make plenty of money, but you're excited to get a $2.00 squeeze-ball from Quest and Redgate #youmightbeaDBA  buckwoody You can't explain to your family what you really do for a living #youmightbeaDBA  buckwoody You tell people that you made a database query go faster, and expect them to be happy for you #youmightbeaDBA  buckwoody You think a millisecond is a really long time #youmightbeaDBA  buckwoody You're sitting and typing #youmightbeaDBA when you could be outside #youmightbeaDBA  buckwoody You can't wait for a technical conference so you can wear a kilt - and you're not Scottish #youmightbeaDBA  buckwoody You know that "DBA" stands for "Default Blame Acceptor" #youmightbeaDBA  buckwoody People can use Access as a cross or garlic on you #youmightbeaDBA  buckwoody You know what "the truth, thole truth and nothing but the truth, so help me Codd" means #youmightbeaDBA  buckwoody You've gotten more help from twitter and facebook than all your years in college #youmightbeaDBA  buckwoody You can't talk fast enough to get a concept out of your head so you tweet it instead #youmightbeaDBA  buckwoody You cry when someone doesn't use a WHERE clause #youmightbeaDBA  buckwoody You think data can be represented as something OTHER than XML #youmightbeaDBA  buckwoody You think "Set theory" is not an verb but a noun #youmightbeaDBA  buckwoody You try to convince random strangers to vote on your Connect item #youmightbeaDBA  buckwoody You think 3 hours of contiguous sleep is a good thing #youmightbeaDBA or #youmightbeamother  buckwoody You don't like Oracle, and not just because of what she did to Neo #youmightbeaDBA  buckwoody You know when to say "sequel" and "s-q-l" #youmightbeaDBA  buckwoody You know where the data is #youmightbeaDBA  buckwoody You refer to your children as "Fully Redundant Mirrors" #youmightbeaDBA  buckwoody Holiday == "Maintenance Window" #youmightbeaDBA  buckwoody Your laptop is more powerful than the servers in most companies - including your own #youmightbeaDBA  buckwoody You capitalize SELECTed words #youmightbeaDBA  buckwoody You take the word "NoSQL" as a personal attack #youmightbeaDBA  buckwoody You know why "user" refers to both business people and crack addicts #youmightbeaDBA  buckwoody You cringe in public when the word "upgrade" is used in a sentence #youmightbeaDBA  buckwoody Holiday == "Maintenance Window" #youmightbeaDBA  buckwoody All Data Is MetaData means something to you #youmightbeaDBA  buckwoody You've never seen the driveway to your house in the daylight #youmightbeaDBA  buckwoody You think that something OTHER than the database might be the performance bottleneck #youmightbeaDBA  buckwoody Most of your bloodstream is composed of caffeine #youmightbeaDBA  buckwoody Your task list is labeled "CRUD Matrix" #youmightbeaDBA  buckwoody You call your wife/husband a "Linked Server" #youmightbeaDBA  anonythemouse When someone tells you they are going to take a dump and you wonder of which database then #youmightbeaDBA  anonythemouse When it's 11pm on a holiday weekend and you are working #youmightbeaDBA  anonythemouse When you sit down at a table and look for it's primary key #youmightbeaDBA  anonythemouse When getting milk from the fridge you check the expiry date is > getdate() #youmightbeaDBA  blakmk when you wake up dreaming about sql #youmightbeaDBA  CharlesGarver You think a @buckwoody bobblehead would be a cool thing to have on the dashboard of your car #youmightbeaDBA  CharlesGarver Your friends don't understand why you think there's a difference between single and double quotes #youmightbeaDBA  CharlesGarver Even the newest employees know your name from all the downtime notices you've sent out #youmightbeaDBA  CharlesGarver You sometimes feel anxious and think "I should test restoring those backups" and then the feeling passes #youmightbeadba  CharlesGarver You know what a co-worker means when they ask "how is your squirrel server?" #youmightbeadba  CharlesGarver You can't sleep at night and you ponder the logisitcs of collecting every copy of Access for the world's biggest bonfire #youmightbeaDBA  CharlesGarver You can't sleep at night and you ponder the logisitcs of collecting every copy of Access for the world's biggest bonfire #youmightbeaDBA  CharlesGarver You're willing to move someone's job up in priority for a box of #voodoodonuts #youmightbeaDBA  CharlesGarver Each person in your company seems to think you work for THEM #youmightbeaDBA  CharlesGarver You have a Love/Hate relationship going on with #Microsoft #youmightbeaDBA  CharlesGarver People ask you to troubleshoot their Access program #youmightbeaDBA  CharlesGarver The first words you hear in the morning are 'your voicemail box is full' #youmightbeaDBA  CharlesGarver The thought of disrupting 500 people's work so you can do something doesn't phase you #youmightbeaDBA  CharlesGarver You can't sleep at night and you ponder the logisitcs of collecting every copy of Access for the world's biggest bonfire #youmightbeaDBA  CharlesGarver Your home computer is backed up in 3 different places #youmightbeaDBA  CharlesGarver Your wardrobe for work includes pajamas #youmightbeaDBA  CharlesGarver Someone tells you to look in the INDEX and you look puzzled before finally going to the back of the book. #youmightbeaDBA  chuckboycejr If you have ever set up a SQLAgent job to email your mobile phone to serve as an alarm clock #youmightbeaDBA  chuckboycejr If you'd rather meet Itzik than Jay Z #youmightbeaDBA  chuckboycejr If you'd rather meet Itzik than Jay Z #youmightbeaDBA  chuckboycejr If you'd wrestle a SysAdmin to the ground to implement #DPA best practices as per @aspiringgeek #youmightbeaDBA  databaseguy I need to be up in 7 hours, so I'm off to bed! I'll have to read the rest of @buckwoody's #youmightbeaDBA posts in the AM. (g'night Buck!)  databaseguy When people ask you about your house, the first thing you describe is the network. #youmightbeaDBA  databaseguy The last thing you say at the office each day is, "is anybody else here? I'm shutting off the lights!" #youmightbeaDBA  databaseguy Your blood pressure rises when you read application specs drafted by marketing. #youmightbeaDBA  databaseguy A good day at work is one when nobody pays you no mind. #youmightbeaDBA  databaseguy You care about latches and wait states. #youmightbeaDBA  databaseguy You have worked over 200 hours on a performance tuning project that required no application changes at all. #youmightbeaDBA  databaseguy The late-night security guard knows the names of your spouse and kids. #youmightbeaDBA  databaseguy You have had vigorous debates about whether it should be pronounced "sequel" or "ess-queue-ell". #youmightbeaDBA  databaseguy You have VPN and RDP software installed on your phone ... just in case. #youmightbeaDBA  databaseguy You have edited a data file by hand, just to see what would happen. #youmightbeaDBA  databaseguy You decorate your office walls with database catalog posters. #youmightbeaDBA  databaseguy You've built programs that access data just to keep other developers from asking you to run queries all the time. #youmightbeaDBA  databaseguy When you watch movies like The Matrix, you find yourself calculating the fasibility of storing all that data. #youmightbeaDBA  databaseguy You have tried to convince someone to spend money on an SSD storage array. #youmightbeaDBA  databaseguy When CPU is spiked on a server, you want to gather forensic evidence. #youmightbeaDBA  databaseguy You have to remind developers not to push code to production without checking if the database is ready. #youmightbeaDBA  databaseguy Nobody cares what you wear to work, as long as the thing keeps running. #youmightbeaDBA  databaseguy Telepathy is a job requirement when working with app dev teams. #youmightbeaDBA  databaseguy You read database statistics for the educational value. #youmightbeaDBA  databaseguy And your boss freely admits this to anyone within earshot. #youmightbeaDBA  databaseguy Your boss cannot explain or understand what you do. #youmightbeaDBA  databaseguy You envision ERDs when you see a GUI. #youmightbeaDBA  databaseguy You say things like "applications come and go, but data lasts forever." #youmightbeaDBA  databaseguy You have memorized the names of several of the AdventureWorks employees. #youmightbeaDBA  databaseguy You know what MAXDOP setting you can get away with for a big query based on current server load. #youmightbeaDBA  databaseguy And you immediately recognize the recursion in my last tweet. #youmightbeaDBA  databaseguy You find 50 simultaneous tweets from @buckwoody about #youmightbeaDBA :O)  DBAishness You have "funny stories" about the times your developers accidentally deleted the T-log in their test environment. #youmightbeaDBA  DBAishness Planning to slice and dice your MDW data with PowerPivot makes you giggle like a schoolgirl. #youmightbeaDBA  donalddotfarmer You think @buckwoody lives in the "real world." #youmightbeaDBA  jamach09 @buckwoody #youmightbeaDBA Why go outside when you can sit in the nice cool server room?  jamach09 If you refer to procreation as "Replication", #youmightbeaDBA.  jamach09 If you think ORM is a four-letter word, #youmightbeaDBA  JamesMarsh If you have ever preached the value of Source Code Control, #YouMightBeADBA  jethrocarr @venzann You store your shopping list in a ACID compliant DB #youmightbeaDBA  joe_positive @buckwoody thought it stood for "Don't Bother Asking" #youmightbeaDBA  joe_positive when you check your IT Events Calendar before making weekend plans #youmightbeaDBA  LadyRuna You cringe whenever someone calls Excel a database #youmightbeaDBA  LadyRuna When the waiter says he'll be your server today, you ask how many terabytes he is #youmightbeaDBA  LadyRuna you always call the asterisk a "Star" #youmightbeaDBA  LadyRuna You walk into a server room, say "Nice RACK!" and everyone there knows you're talking about server rack... #youmightbeaDBA  LadyRuna You receive more messages from servers than from friends #youmightbeaDBA  LadyRuna hmmm... #youmightbeaDBA if your recipe for gumbo is "SELECT * FROM Refrigerator"  markjholmes @SQLSoldier Heh. #youmightbeaDBA if you correct other DBAs' spelling of @PaulRandal  markjholmes #youmightbeaDBA if you actually test RAID5 vs RAID10 on your SAN because when it comes to configuration, "it depends."  markjholmes #youmightbeaDBA if you have at least 3 definitions of the word "cluster"  MarlonRibunal 3 Words: @BrentO, snicker, & Access #youmightbeaDBA  MarlonRibunal @onpnt @mikeSQL my appeal was a couple of mins late. Enjoying #youmightbeaDBA  MarlonRibunal @mikeSQL @onpnt pls, don't mention bacon #youmightbeaDBA  merv @buckwoody You HATE 3-way joins #youmightbeaDBA  MidnightDBA If you're up at midnight Tweeting about SQL #youmightbeaDBA  MidnightDBA @buckwoody I'd noticed that. :) #youmightbeaDBA  mikeSQL when people talk about "their type" you're thinking varchar, bigint, binary, etc #youmightbeadba  mikeSQL people ask you to go to lunch , but you can't go because you're attending #SQLlunch #youmightbeadba  mikeSQL you laugh for hours at all of the #sqlmoviequotes ....things in which a normal individual would scratch their head at. #youmightbeadba  mikeSQL you laugh for hours at all of the #sqlmoviequotes ....things in which a normal individual would scratch their head at. #youmightbeadba  mrdenny If you think that @buckwoody's demo using PowerPivot to analyze index usage data from DMVs is awesome then #youmightbeaDBA  mrdenny You wish @PaulRandal still worked at Microsoft so that they would make a bobble head of him #youmightbeadba  mrdenny When it's 11pm on a holiday weekend, and your posting stupid jokes on Twitter then #youmightbeadba  mrdenny If you go out with friends and wonder why no one's wearing a kilt then #YouMightBeADBA  mrdenny You can't do basic math, but you know off the top of your head how many CALs $14,412 can buy you. #YoumightbeaDBA  mrdenny If you've ever setup a SQL Job to email you to get you out of a regularly scheduled meeting #YouMightBeADBA.  mrdenny You throw up in your mouth a little when ever you here the word "Access". Even if it doesn't relate to a MS product. #YouMightBeADBA  msdtjones You spend more time listening to @buckwoody than your wife #youmightbeaDBA  NFDotCom You perform "hail deltas" on a regular basis. #YouMightBeADBA  NoelMcKinney If you tell your wife you want to go to Columbus Ohio for your wedding anniversary so you can attend #sqlsat42 then #youmightbeaDBA  NoelMcKinney You read a union is on strike and wonder if it's a UNION ALL #youmightbeaDBA  NoelMcKinney You read a union is on strike and wonder if it's a UNION ALL #youmightbeaDBA  NoelMcKinney Someone asks you to throw another log on the fire and you tell them not to worry about it because Autogrowth is turned on #youmightbeaDBA  Nuurdygirl Even if you have a girlfriend...its possible #youmightbeadba. Yeah-i said its possible!  Nuurdygirl When your girlfriend has to lean around the laptop to kiss you goodnight #youmightbeadba  Old_Man_Fish If you worry about how big your package is and how long it takes to finish #youmightbeaDBA  Old_Man_Fish If you no longer wonder if someone is in trouble or died if you are getting calls at 2AM #youmightbeaDBA  Old_Man_Fish If, when you hear the word ACCESS with no connotation you blood pressure jumps 50 points, #youmightbeaDBA  onpnt When you hear the word inject you immediately get concerned if your databases are OK #youmightbeaDBA  onpnt Your servers haven't been rebooted in a year #youmightbeaDBA  onpnt You know why it's funny when @PaulRandal has the word, "Sheep" in a tweet #youmightbeaDBA  onpnt You have read BOL without actually having a problem to figure out #youmightbeaDBA  onpnt You can type "SELECT columns FROM tables" without typos but tipen ni Banglish ares a messis #youmightbeaDBA  onpnt DR strategies doesn't include the word, RAID in them #youmightbeaDBA  onpnt you can move a SQL Server instance to a new server without the users ever knowing #youmightbeaDBA  onpnt You have made an SSIS package that is more than one step #youmightbeaDBA  onpnt You have the balls to say no to your boss when they ask for the sa password #youmightbeaDBA  onpnt you google to trouble shoot a problem and end up at your own blog (and it fixes it) #youmightbeaDBA  onpnt You talk your wife into moving the family vacation a week earlier so you can attend the areas local SSUG meeting #youmightbeaDBA  onpnt you can explain to a nontechnical person what a deadlock is #youmightbeaDBA  onpnt You hope a girl asks you what your collation is #youmightbeaDBA  onpnt you make jokes that include the words shrink, truncate and 1205. And you are the only one that laughs at them #youmightbeaDBA  onpnt You rate your ability to stay awake to work longer on blogs, twitter, forums and your day to day job with the 5 9's goal #youmightbeaDBA  onpnt you have major surgery and beg the doctor to release you back to work 5 days later because you miss your servers #youmightbeaDBA #TrueStory  onpnt You do have backups and you know how to use them #youmightbeaDBA  onpnt It's the network #youmightbeaDBA  onpnt When the developers get to work your mood changes rapidly #youmightbeaDBA  onpnt When someone says, "PASS", you first think of karaoke #youmightbeaDBA  onpnt Recruiters try to get you to call them *just* because they think you'll give them @BrentO contact info #youmightbeaDBA  onpnt You chuckle every time you go to grab the "CLR" Calcium, Lime and Rust Remover to clean something #youmightbeaDBA  onpnt @MarlonRibunal @mikeSQL Sorry man, it was already in motion ;-) #youmightbeaDBA  onpnt When you have an "I love bacon" sticker on your laptop. #youmightbeaDBA http://twitpic.com/1ry671  onpnt You sing SELECT statements in the shower #youmightbeaDBA  onpnt When you see a chicken it doesn't remind you of food. It reminds you of a guy named Jorge #youmightbeaDBA  onpnt At time, SQL is your mistress #youmightbeaDBA  onpnt Your wife wonders if SQL is the code name of your mistress at times #youmightbeaDBA  onpnt it's Friday and you are on twitter thinking really hard about what would be funny for hash tag #youmightbeaDBA  onpnt You organize your wife's "decorative"pillows on the bed in a B-Tree structure #youmightbeaDBA  PaulWhiteNZ If you: SELECT TOP (1) milk FROM fridge WHERE use_by_date >= GET_DATE() ORDER BY use_by_date ASC #YouMightBeaDBA  RonDBA #youmightbeaDBA if you read @buckwoody's and @BrentO's blogs.  ryaneastabrook @buckwoody omg, you have to stand up a website with these on them, they are awesome #youmightbeaDBA  soulvy @StrateSQL @LadyRuna Or a "Splat" #youmightbeaDBA  speedracer You can still fall asleep after three cups of coffee #youmightbeaDBA  speedracer You retweet @buckwoody on a Friday night #youmightbeaDBA  speedracer You can still fall asleep after three cups of coffee #youmightbeaDBA  speedracer Developers make you twitch #youmightbeaDBA  sqlagentman You know what X/1024*8 is. #YouMightBeADBA  SqlAsylum Your still in the office at 5:00 on memorial day weekend. #youmightbeadba :)  SQLBob Whenever someone you know gets pregnant you bring up INNER JOINs or SQL Injection attacks... #youmightbeaDBA  SQLChicken You know one or more SQL folks in the community with an animal in their username #youmightbeaDBA  SQLChicken You've used one or more car analogies to explain how a database works #youmightbeaDBA  SQLChicken “@sqljoe: #youmightbeaDBA if you applied to attend #sqlu and requested @SQLChicken to pull strings for you” lmao nice!  SQLChicken When talking about SSIS your discussions break down into various jokes about packages #youmightbeaDBA  SQLChicken Just SEEING the code for cursors makes you break out in hives #youmightbeaDBA  SQLChicken Just SEEING the code for cursors makes you break out in hives #youmightbeaDBA  SQLCraftsman You coined the phrase "Magic SAN Dust" because calling a vendor's marketing claims BS is not acceptable in a meeting. #YouMightBeADBA  SQLCraftsman If you hear about a new feature with the acronym "DAC" and wonder what disaster of a feature it is attached to this time. #YouMightBeADBA  SQLCraftsman You really own a "Stick of Much Developer Whacking" #YouMightBeADBA  SQLCraftsman You coined the phrase "Magic SAN Dust" because calling a vendor's marketing claims BS is not acceptable in a meeting. #YouMightBeADBA  SQLCraftsman Default Blame Acceptor #YouMightBeADBA  SQLCraftsman If you hear about a new feature with the acronym "DAC" and wonder what disaster of a feature it is attached to this time. #YouMightBeADBA  SQLCraftsman Default Blame Acceptor #YouMightBeADBA  SQLCraftsman If you hear about a new feature with the acronym "DAC" and wonder what disaster of a feature it is attached to this time. #YouMightBeADBA  sqljoe #youmightbeaDBA if you wished your wife knew T-sql. USE ShoppingList SELECT NecessaryItems from Supermarket WHERE Category<> ("junk food")  sqljoe #youmightbeaDBA if the first thing you kiss when you wake up is your mobile for not waking you up in the middle of the night  sqljoe #youmightbeaDBA if your wife has a "Do Not Fly" family vacation list of her own including your laptop and mobile  sqljoe #youmightbeaDBA if you have researched for DBA Anonymous groups and attended a #SSUG willing to drop your database (vice)  sqljoe #youmightbeaDBA if your only maintenance windows are staff meetings  sqljoe #youmightbeaDBA if you think of yourself as "The One" in The Matrix "balancing the equation" from The Architect's (developers) poor coding  sqljoe #youmightbeaDBA if you think @PaulRandal should have played the Oracle in The Matrix  sqljoe #youmightbeaDBA if home CD & Movie collection is stored in secured containers,in logical order & naming convention,and with a backup copy  sqljoe #youmightbeaDBA if you applied to attend #sqlu and requested @SQLChicken to pull strings for you  sqljoe #youmightbeaDBA if you have tried to TiVo @MidnightDBA broadcasts  sqljoe #youmightbeaDBA if your #sql user group feels like #AA meetings  sqljoe #youmightbeaDBA if you thought of bringing your #sql books to #sqlsaturday and #sqlpass for autographs  sqljoe #youmightbeaDBA if #sqlpass feels like the #oscars  sqljoe #youmightbeaDBA if you are proud of your small package  SQLLawman #youmightbeaDBA when you hear MDX and Acura is not first thought that comes to mind.  sqlrunner If your wife double checks that there isn't a SQLSat within 200 miles of your vacation destination #youmightbeaDBA  sqlrunner When you're on a conference call and your wife thinks your speaking in a foreign language #youmightbeaDBA  sqlrunner When you're on a conference call and your wife thinks your speaking in a foreign language #youmightbeaDBA  sqlrunner You treat the word 'access' as a verb, not a noun #youmightbeaDBA  sqlrunner If you are happy with sub-second performance #youmightbeaDBA  sqlrunner When you know the names of the NOC people AND their families #youmightbeadba  sqlrunner When you know the names of the NOC people AND their families #youmightbeadba  sqlrunner Your company set's up international phone coverage for your cruise #youmightbeaDBA  sqlsamson @buckwoody if your manager asks you for data and you respond with "there's a script for that" #youmightbeadba  sqlsamson @buckwoody If you receive more messages from your server then your spouse #youmightbeadba  SQLSoldier You've spent all night Valentines Day upgrading the SQL Servers and forgot to tell your wife you'd be working late. #youmightbeadba  SQLSoldier You're flattered when someone calls you a geek. #youmightbeadba  SQLSoldier @llangit @mrdenny it's 11pm on a holiday weekend, & your reading stupid jokes on Twitter then #youmightbeadba  SQLSoldier Your manager borrows lunch money from you because your salary is 30% higher than his. #youmightbeaDBA  SQLSoldier You think "intellisense" is a double negative because it's not intelligent nor makes sense. #youmightbeaDBA  SQLSoldier 75% of the emails you receive at home have the phrase "now following you on Twitter!" in the subject line. #youmightbeaDBA  SQLSoldier You petition Ken Burns to remake Office Space because it should have been 18 hours long. #youmightbeaDBA  SQLSoldier You select a candidate for a Jr DBA position because his resume said he's willing to get your coffee. #youmightbeaDBA  SQLSoldier Somebody misquotes @PaulRandall and you call him on your cell to verify. #youmightbeaDBA  SQLSoldier You wish the elevator in your building was slower because it's the last time you'll be left alone all day. #youmightbeaDBA  SQLSoldier The developers sacrifice small animals before giving you their code for review. #youmightbeaDBA  SQLSoldier Developers bring you coffee and a BLT when you review their code. #youmightbeaDBA #IWish  SQLSoldier You can get out of any family get-together by saying you have to work and nobody questions it. #youmightbeaDBA  SQLSoldier You've requested a HP Superdome for you "test" box. #youmightbeaDBA  SQLSoldier Your leave work early because your internet connection to the data center is better at home #youmightbeaDBA  SQLSoldier The new CEO asks you to justify your salary, so you go on vacation for 2 weeks. And he never questions you again. #youmightbeaDBA  SQLSoldier You cheer when Milton burns down the company in Office Space #youmightbeaDBA  SQLSoldier A dev. asks if you've heard about some great new feature in SQL and you show the 16 blog posts you wrote on it ... last year #youmightbeaDBA  SQLSoldier Your dev team is still testing SQL 2008 and you're already planning for SQL 11. #youmightbeaDBA #TrueStory  SQLSoldier The new CEO asks you to justify your salary, so you go on vacation for 2 weeks. And he never questions you again. #youmightbeaDBA  SQLSoldier Your dev team is still testing SQL 2008 and you're already planning for SQL 11. #youmightbeaDBA  SQLSoldier You use a cell phone service coverage map to plan your next vacation. #youmightbeaDBA  SQLSoldier You come in to work at 7 AM because it gives you at least 3 hours without any developers around. #youmightbeaDBA  SQLSoldier You figure out a way to make take your wife on a cruise and deduct it as a business expense. #youmightbeaDBA #sqlcruise  SQLSoldier You name your cat SQLDog because the name @SQLCat was already taken. #youmightbeaDBA  SQLSoldier You rate your blog posts based on the number of retweets you get. #youmightbeaDBA  SQLSoldier You disable random logins just to mess with people. #youmightbeaDBA  SQLSoldier You fall for the pickup line, "Hey baby, what's your collation?" #youmightbeaDBA  SQLSoldier You can blame an outage on anyone in the company because you're the only one that knows how to find out what really happened #youmightbeaDBA  SQLSoldier You can blame an outage on anyone in the company because you're the only one that knows how to find out what really happened #youmightbeaDBA  SQLSoldier You cheer when Milton burns down the company in Office Space #youmightbeaDBA  SQLSoldier Your leave work early because your internet connection to the data center is better at home #youmightbeaDBA  SQLSoldier You cheer when Milton burns down the company in Office Space #youmightbeaDBA  SQLSoldier Your think the 4 food groups are coffee, bacon, fast food, and Mountain Dew. #youmightbeaDBA  SQLSoldier You tell someone your job title and they ask "What?" You describe it and they ask "What?". So you say "computer geek". #youmightbeaDBA  SQLSoldier The #1 referrer to your blog is Twitter.com. #youmightbeaDBA  SQLSoldier Your idea of a good time on a Saturday involves free training. #youmightbeaDBA #sqlsat43  SQLSoldier You write a book that all of your co-workers have and none have read it. #youmightbeaDBA  SQLSoldier You write a book that sells a couple thousand copies and is heralded a best seller. #youmightbeaDBA  SQLSoldier No matter how sick you are, you go to work if it's time to pass the pager on to the next guy. #youmightbeaDBA #TrueStory  SQLSoldier You go out on the town, and strangers walk up to you and say, "Hey you're that SQL guy" #youmightbeaDBA #TrueStory  SQLSoldier Your wife asks you to fix something, and you request a downtime window. #youmightbeaDBA  SQLSoldier Your wife asks when you'll be home, and you tell her that you wish you knew. #youmightbeaDBA  SQLSoldier Your best pickup line, "Hey baby, what's your collation?" #youmightbeaDBA  SQLSoldier Your wife asks when you'll be home, and you tell her that you wish you knew. #youmightbeaDBA  SQLSoldier You know that @BuckWoody is not someone's porno name. #youmightbeaDBA  SQLSoldier You list TSQL as your native language on the 2010 census. #youmightbeaDBA  SQLSoldier Starbucks' stock price drops every time you go on vacation. #youmightbeaDBA  SQLSoldier You're happy when the web master says that the website is down. #youmightbeaDBA  SQLSoldier You know that @BuckWoody is not someone's porno name. #youmightbeaDBA  SQLSoldier You get mad when someone calls your car a "heap" because you've always considered it to be a "clustered index". #youmightbeaDBA  SQLSoldier Your blog has more hits than your company's website. #youmightbeaDBA  SQLSoldier You systematically remove the asterisk key from all keyboards in the company except yours. #youmightbeaDBA  SQLSoldier When asked if you recycle, you reply that you run sp_cycle_errorlog every night at midnight #youmightbeaDBA  SQLSoldier You wouldn't allow someone named @AdamMachanic to work on your car. #youmightbeaDBA  SQLSoldier You switch offices every 3 days to avoid developers #youmightbeaDBA  SQLSoldier PSS has your number on speed dial. #youmightbeaDBA  SQLSoldier You frown when you they tell Neo that he's going to the Oracle #youmightbeaDBA  swhaley you regretted saying "This shouldn't effect production" #youmightbeaDBA  swhaley you regretted saying "This shouldn't effect production" #youmightbeaDBA  Tarwn A pleasurable saturday means spending the day learning more about what you already do the rest of the week #youmightbeaDBA ...oh, wait...  thelostforum For great justice; all our base are belong to YOU !! #youmightbeadba  thelostforum @SQLSoldier: You need a witness to use a mirror #youmightbeaDBA ;)  TimCost you capitalize key words. always. everywhere. you can't help it, usually don't even notice. #youmightbeaDBA  Toshana Your the only one in your company not impressed with the developers new application. #youmightbeaDBA  venzann Coming soon from a (respected) book publisher - @buckwoody's #youmightbeaDBA  venzann He's on a role tonight. @buckwoody is summing up my life with his #youmightbeaDBA tweets...  venzann I love the #youmightbeaDBA tag. Found at least 6 new DBAs to follow..  venzann He's on a role tonight. @buckwoody is summing up my life with his #youmightbeaDBA tweets...  venzann You use #sqlhelp as a primary resource during troubleshooting #youmightbeaDBA  venzann You insist on stricter password security for your sql servers than you implement on your own laptop #youmightbeaDBA  WesBrownSQL @buckwoody you are up so late the only tweets you see are from @buckwoody #youmightbeaDBA  WesBrownSQL @SQLSoldier you are upgrading all your 2005 prod servers to 2008 R2 on a three day weekend... #youmightbeaDBA  zippy1981 #youmightbeaDBA if everytime you do something with #mongodb you think of the Vulcan proverb "only Nixon could go to China."  Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• SQL SERVER – CXPACKET – Parallelism – Advanced Solution – Wait Type – Day 7 of 28

  - by pinaldave

  Earlier we discussed about the what is the common solution to solve the issue with CXPACKET wait time. Today I am going to talk about few of the other suggestions which can help to reduce the CXPACKET wait. If you are going to suggest that I should focus on MAXDOP and COST THRESHOLD – I totally agree. I have covered them in details in yesterday’s blog post. Today we are going to discuss few other way CXPACKET can be reduced. Potential Reasons: If data is heavily skewed, there are chances that query optimizer may estimate the correct amount of the data leading to assign fewer thread to query. This can easily lead to uneven workload on threads and may create CXPAKCET wait. While retrieving the data one of the thread face IO, Memory or CPU bottleneck and have to wait to get those resources to execute its tasks, may create CXPACKET wait as well. Data which is retrieved is on different speed IO Subsystem. (This is not common and hardly possible but there are chances). Higher fragmentations in some area of the table can lead less data per page. This may lead to CXPACKET wait. As I said the reasons here mentioned are not the major cause of the CXPACKET wait but any kind of scenario can create the probable wait time. Best Practices to Reduce CXPACKET wait: Refer earlier article regarding MAXDOP and Cost Threshold. De-fragmentation of Index can help as more data can be obtained per page. (Assuming close to 100 fill-factor) If data is on multiple files which are on multiple similar speed physical drive, the CXPACKET wait may reduce. Keep the statistics updated, as this will give better estimate to query optimizer when assigning threads and dividing the data among available threads. Updating statistics can significantly improve the strength of the query optimizer to render proper execution plan. This may overall affect the parallelism process in positive way. Bad Practice: In one of the recent consultancy project, when I was called in I noticed that one of the ‘experienced’ DBA noticed higher CXPACKET wait and to reduce them, he has increased the worker threads. The reality was increasing worker thread has lead to many other issues. With more number of the threads, more amount of memory was used leading memory pressure. As there were more threads CPU scheduler faced higher ‘Context Switching’ leading further degrading performance. When I explained all these to ‘experienced’ DBA he suggested that now we should reduce the number of threads. Not really! Lower number of the threads may create heavy stalling for parallel queries. I suggest NOT to touch the setting of number of the threads when dealing with CXPACKET wait. Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest reading book on-line for further clarification. All the discussion of Wait Stats over here is generic and it varies by system to system. You are recommended to test this on development server before implementing to production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• SQL SERVER – Shard No More – An Innovative Look at Distributed Peer-to-peer SQL Database

  - by pinaldave

  There is no doubt that SQL databases play an important role in modern applications. In an ideal world, a single database can handle hundreds of incoming connections from multiple clients and scale to accommodate the related transactions. However the world is not ideal and databases are often a cause of major headaches when applications need to scale to accommodate more connections, transactions, or both. In order to overcome scaling issues, application developers often resort to administrative acrobatics, also known as database sharding. Sharding helps to improve application performance and throughput by splitting the database into two or more shards. Unfortunately, this practice also requires application developers to code transactional consistency into their applications. Getting transactional consistency across multiple SQL database shards can prove to be very difficult. Sharding requires developers to think about things like rollbacks, constraints, and referential integrity across tables within their applications when these types of concerns are best handled by the database. It also makes other common operations such as joins, searches, and memory management very difficult. In short, the very solution implemented to overcome throughput issues becomes a bottleneck in and of itself. What if database sharding was no longer required to scale your application? Let me explain. For the past several months I have been following and writing about NuoDB, a hot new SQL database technology out of Cambridge, MA. NuoDB is officially out of beta and they have recently released their first release candidate so I decided to dig into the database in a little more detail. Their architecture is very interesting and exciting because it completely eliminates the need to shard a database to achieve higher throughput. Each NuoDB database consists of at least three or more processes that enable a single database to run across multiple hosts. These processes include a Broker, a Transaction Engine and a Storage Manager.  Brokers are responsible for connecting client applications to Transaction Engines and maintain a global view of the network to keep track of the multiple Transaction Engines available at any time. Transaction Engines are in-memory processes that client applications connect to for processing SQL transactions. Storage Managers are responsible for persisting data to disk and serving up records to the Transaction Managers if they don’t exist in memory. The secret to NuoDB’s approach to solving the sharding problem is that it is a truly distributed, peer-to-peer, SQL database. Each of its processes can be deployed across multiple hosts. When client applications need to connect to a Transaction Engine, the Broker will automatically route the request to the most available process. Since multiple Transaction Engines and Storage Managers running across multiple host machines represent a single logical database, you never have to resort to sharding to get the throughput your application requires. NuoDB is a new pioneer in the SQL database world. They are making database scalability simple by eliminating the need for acrobatics such as sharding, and they are also making general administration of the database simpler as well.  Their distributed database appears to you as a user like a single SQL Server database.  With their RC1 release they have also provided a web based administrative console that they call NuoConsole. This tool makes it extremely easy to deploy and manage NuoDB processes across one or multiple hosts with the click of a mouse button. See for yourself by downloading NuoDB here. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: CodeProject, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology Tagged: NuoDB

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• What's New in Oracle's EPM System?

  - by jmorourke

  Oracle’s EPM System R11.1.2.2  is now generally available to customers and partners on the download center.  Although the release number doesn’t sound significant, this is a major release of Oracle’s Hyperion EPM Suite with new modules as well as significant enhancements across the suite.  This release was announced back on April 4th as part of Oracle’s Business Analytics Strategy launch, so analytics is a key aspect of the release.  But the three biggest pieces of news in this release are Oracle Hyperion Planning support for the Exalytics In-Memory Machine, the new Project Financial Planning Application and the new Account Reconciliations Manager module. The Oracle Exalytics In-Memory Machine was announced back in October 2011, at Oracle OpenWorld.  It’s the latest installment from Oracle in a line of engineered systems that combine Oracle Sun hardware, with Oracle database and application technologies – in solutions that are designed to provide high scalability and performance for specific tasks.  Exalytics is the first engineered system specifically designed for high performance analytics.  Running in-memory versions of Oracle Essbase, as well as the Oracle TimesTen database and Oracle BI tools, Exalytics provides speed of thought response times for complex analytic processes with advanced visualizations.  Early adopter customers have achieved 5X to 100X faster interactivity and 6X to 10X faster planning cycles.  Hyperion Planning running with Oracle Exalytics will support enterprise-wide planning, budgeting and forecasting with more detailed data, with hundreds to thousands of users across an organization getting speed of thought performance. The new Hyperion Project Financial Planning application delivered with EPM 11.1.2.2 is also great news for Oracle customers.  This application follows on the heels of other special-purpose planning applications that Oracle has delivered for Workforce and Capital Asset planning.  It allows Project Managers to identify project-related expenses and revenues, plan and propose new projects, and track results over time. Finance Managers can evaluate and compare different projects, manage the funding process, monitor and report the actual financial results and impacts of projects and project portfolios. This new application is applicable to capital projects, contract projects and indirect projects like IT and HR projects across all industries.  This application is a great complement to existing Project Management applications, and helps bridge the gap between these applications, and the financial planning and budgeting process. Account reconciliations has to be one of the biggest bottlenecks and risks in the financial close and reporting process, and many organizations rely on spreadsheets and manual processes to perform this critical process.  To help address this problem, Oracle developed an Account Reconciliation Manager module that is being delivered as part of Oracle Hyperion Financial Close Management.   This module helps automate and streamline account reconciliations and eliminates the chances for errors, omissions and fraud.  But unlike standalone account reconciliation packages, it’s integrated with the rest of the Oracle Hyperion Financial Close suite, and can integrate balances from any source system.  This can help alleviate a major bottleneck in the financial close process, increase accuracy and reduce risk, and can complement existing investments in Hyperion Financial Management, as well as Oracle and non-Oracle transaction processing systems. Other enhancements in this release include an enhanced Web 2.0 interface for Hyperion Planning and Hyperion Financial Management (HFM), configurable dimensionality in HFM, new Predictive Planning feature in Hyperion Planning, new Detailed Profitability feature in Hyperion Profitability and Cost Management, new Smart View interface for Hyperion Strategic Finance, and integration of the Hyperion applications with JD Edwards Financials. For more information about Oracle EPM System R11.1.2.2 check out the links below: Press Release:  http://www.oracle.com/us/corporate/press/1575775 Product Information on O.com:  http://www.oracle.com/us/solutions/business-analytics/overview/index.html Product Information on OTN:  http://www.oracle.com/technetwork/middleware/epm/downloads/index.html Webcast Replay:  http://www.oracle.com/us/go/index.html?Src=7317510&Act=65&pcode=WWMK11054701MPP046 Please contact me if you have any questions or need additional information – [email protected]

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• Production Access Denied! Who caused this rule anyways?

  - by Matt Watson

  One of the biggest challenges for most developers is getting access to production servers. In smaller dev teams of less than about 5 people everyone usually has access. Then you hire developer #6, he messes something up in production... and now nobody has access. That is how it always starts in small dev teams. I think just about every rule of life there is gets created this way. One person messes it up for the rest of us. Rules are then put in place to try and prevent it from happening again.Breaking the rules is in our nature. In this example it is for good cause and a necessity to support our applications and troubleshoot problems as they arise. So how do developers typically break the rules? Some create their own method to collect log files off servers so they can see them. Expensive log management programs can collect log files, but log files alone are not enough. Centralizing where important errors are logged to is common. Some lucky developers are given production server access by the IT operations team out of necessity. Wait. That's not fair to all developers and knowingly breaks the company rule!  When customers complain or the system is down, the rules go out the window. Commonly lead developers get production access because they are ultimately responsible for supporting the application and may be the only person who knows how to fix it. The problem with only giving lead developers production access is it doesn't scale from a support standpoint. Those key employees become the go to people to help solve application problems, but they also become a bottleneck. They end up spending up to half of their time every day helping resolve application defects, performance problems, or whatever the fire of the day is. This actually the last thing you want your lead developers doing. They should be working on something more strategic like major enhancements to the product. Having production access can actually be a curse if you are the guy stuck hunting down log files all day. Application defects are good tasks for junior developers. They can usually handle figuring out simple application problems. But nothing is worse than being a junior developer who can't figure out those problems and the back log of them grows and grows. Some of them require production server access to verify a deployment was done correctly, verify config settings, view log files, or maybe just restart an application. Since the junior developers don't have access, they end up bugging the developers who do have access or they track down a system admin to help. It can take hours or days to see server information that would take seconds or minutes if they had access of their own. It is very frustrating to the developer trying to solve the problem, the system admin being forced to help, and most importantly your customers who are not happy about the situation. This process is terribly inefficient. Production database access is also important for solving application problems, but presents a lot of risk if developers are given access. They could see data they shouldn't.  They could write queries on accident to update data, delete data, or merely select every record from every table and bring your database to its knees. Since most of the application we create are data driven, it can be very difficult to track down application bugs without access to the production databases.Besides it being against the rule, why don't all developers have access? Most of the time it comes down to security, change of control, lack of training, and other valid reasons. Developers have been known to tinker with different settings to try and solve a problem and in the process forget what they changed and made the problem worse. So it is a double edge sword. Don't give them access and fixing bugs is more difficult, or give them access and risk having more bugs or major outages being created!Matt WatsonFounder, CEOStackifyAgile Support for Agile Developers

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• Organization &amp; Architecture UNISA Studies &ndash; Chap 6

  - by MarkPearl

  Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

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• DirectX particle system. ConstantBuffer

  - by Liuka

  I'm new in DirectX and I'm making a 2D game. I want to use a particle system to simulate a 3D starfield, so each star has to set its own constant buffer for the vertexshader es. to set it's world matrix. So if i have 500 stars (that move every frame) i need to call 500 times VSsetconstantbuffer, and map/unmap each buffer. with 500 stars i have an average of 220 fps and that's quite good. My bottelneck is Vs/PsSetconstantbuffer. If i dont call this function i have 400 fps(obliviously nothing is display, since i dont set the position of the stars). So is there a method to speed up the render of the particle system?? Ps. I'm using intel integrate graphic (hd 2000-3000). with a nvidia (or amd) gpu will i have the same bottleneck?? If, for example, i dont call setshaderresource i have 10-20 fps more (for 500 objcets), that is not 180.Why does SetConstantBuffer take so long?? LPVOID VSdataPtr = VSmappedResource.pData; memcpy(VSdataPtr, VSdata, CszVSdata); context->Unmap(VertexBuffer, 0); result = context->Map(PixelBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &PSmappedResource); if (FAILED(result)) { outputResult.OutputErrorMessage(TITLE, L"Cannot map the PixelBuffer", &result, OUTPUT_ERROR_FILE); return; } LPVOID PSdataPtr = PSmappedResource.pData; memcpy(PSdataPtr, PSdata, CszPSdata); context->Unmap(PixelBuffer, 0); context->VSSetConstantBuffers(0, 1, &VertexBuffer); context->PSSetConstantBuffers(0, 1, &PixelBuffer); this update and set the buffer. It's part of the render method of a sprite class that contains a the vertex buffer and the texture to apply to the quads(it's a 2d game) too. I have an array of 500 stars (sprite setup with a star texture). Every frame: clear back buffer; draw the array of stars; present the backbuffer; draw also call the function update( which calculate the position of the sprite on screen based on a "camera class") Ok, create a vertex buffer with the vertices of each quads(stars) seems to be good, since the stars don't change their "virtual" position; so.... In a particle system (where particles move) it's better to have all the object in only one vertices array, rather then an array of different sprite/object in order to update all the vertices' position with a single setbuffer call. In this case i have to use a dynamic vertex buffer with the vertices positions like this: verticesForQuad={{ XMFLOAT3((float)halfDImensions.x-1+pos.x, (float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(1.0f, 0.0f) }, { XMFLOAT3((float)halfDImensions.x-1+pos.x, -(float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(1.0f, 1.0f) }, { XMFLOAT3(-(float)halfDImensions.x-1+pos.x, (float)halfDImensions.y-1.pos.y, 1.0f), XMFLOAT2(0.0f, 0.0f) }, { XMFLOAT3(-(float)halfDImensions.x-1.pos.x, -(float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(0.0f, 1.0f) }, ....other quads} where halfDimensions is the halfsize in pixel of a texture and pos the virtual position of a star. than create an array of verticesForQuad and create the vertex buffer ZeroMemory(&vertexDesc, sizeof(vertexDesc)); vertexDesc.Usage = D3D11_USAGE_DEFAULT; vertexDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER; vertexDesc.ByteWidth = sizeof(VertexType)* 4*numStars; ZeroMemory(&resourceData, sizeof(resourceData)); resourceData.pSysMem = verticesForQuad; result = device->CreateBuffer(&vertexDesc, &resourceData, &CvertexBuffer); and call each frame Context->IASetVertexBuffers(0, 1, &CvertexBuffer, &stride, &offset); But if i want to add and remove obj i have to recreate the buffer each time, havent i?? There is a faster way? I think i can create a vertex buffer with a max size (es. 10000 objs) and when i update it set only the 250 position (for 250 onjs for example) and pass this number as the vertexCount to the draw function (numObjs*4), or i'm worng

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• High Resolution Timeouts

  - by user12607257

  The default resolution of application timers and timeouts is now 1 msec in Solaris 11.1, down from 10 msec in previous releases. This improves out-of-the-box performance of polling and event based applications, such as ticker applications, and even the Oracle rdbms log writer. More on that in a moment. As a simple example, the poll() system call takes a timeout argument in units of msec: System Calls poll(2) NAME poll - input/output multiplexing SYNOPSIS int poll(struct pollfd fds[], nfds_t nfds, int timeout); In Solaris 11, a call to poll(NULL,0,1) returns in 10 msec, because even though a 1 msec interval is requested, the implementation rounds to the system clock resolution of 10 msec. In Solaris 11.1, this call returns in 1 msec. In specification lawyer terms, the resolution of CLOCK_REALTIME, introduced by POSIX.1b real time extensions, is now 1 msec. The function clock_getres(CLOCK_REALTIME,&res) returns 1 msec, and any library calls whose man page explicitly mention CLOCK_REALTIME, such as nanosleep(), are subject to the new resolution. Additionally, many legacy functions that pre-date POSIX.1b and do not explicitly mention a clock domain, such as poll(), are subject to the new resolution. Here is a fairly comprehensive list: nanosleep pthread_mutex_timedlock pthread_mutex_reltimedlock_np pthread_rwlock_timedrdlock pthread_rwlock_reltimedrdlock_np pthread_rwlock_timedwrlock pthread_rwlock_reltimedwrlock_np mq_timedreceive mq_reltimedreceive_np mq_timedsend mq_reltimedsend_np sem_timedwait sem_reltimedwait_np poll select pselect _lwp_cond_timedwait _lwp_cond_reltimedwait semtimedop sigtimedwait aiowait aio_waitn aio_suspend port_get port_getn cond_timedwait cond_reltimedwait setitimer (ITIMER_REAL) misc rpc calls, misc ldap calls This change in resolution was made feasible because we made the implementation of timeouts more efficient a few years back when we re-architected the callout subsystem of Solaris. Previously, timeouts were tested and expired by the kernel's clock thread which ran 100 times per second, yielding a resolution of 10 msec. This did not scale, as timeouts could be posted by every CPU, but were expired by only a single thread. The resolution could be changed by setting hires_tick=1 in /etc/system, but this caused the clock thread to run at 1000 Hz, which made the potential scalability problem worse. Given enough CPUs posting enough timeouts, the clock thread could be a performance bottleneck. We fixed that by re-implementing the timeout as a per-CPU timer interrupt (using the cyclic subsystem, for those familiar with Solaris internals). This decoupled the clock thread frequency from timeout resolution, and allowed us to improve default timeout resolution without adding CPU overhead in the clock thread. Here are some exceptions for which the default resolution is still 10 msec. The thread scheduler's time quantum is 10 msec by default, because preemption is driven by the clock thread (plus helper threads for scalability). See for example dispadmin, priocntl, fx_dptbl, rt_dptbl, and ts_dptbl. This may be changed using hires_tick. The resolution of the clock_t data type, primarily used in DDI functions, is 10 msec. It may be changed using hires_tick. These functions are only used by developers writing kernel modules. A few functions that pre-date POSIX CLOCK_REALTIME mention _SC_CLK_TCK, CLK_TCK, "system clock", or no clock domain. These functions are still driven by the clock thread, and their resolution is 10 msec. They include alarm, pcsample, times, clock, and setitimer for ITIMER_VIRTUAL and ITIMER_PROF. Their resolution may be changed using hires_tick. Now back to the database. How does this help the Oracle log writer? Foreground processes post a redo record to the log writer, which releases them after the redo has committed. When a large number of foregrounds are waiting, the release step can slow down the log writer, so under heavy load, the foregrounds switch to a mode where they poll for completion. This scales better because every foreground can poll independently, but at the cost of waiting the minimum polling interval. That was 10 msec, but is now 1 msec in Solaris 11.1, so the foregrounds process transactions faster under load. Pretty cool.

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• Disk performance below expectations

  - by paulH

  this is a follow-up to a previous question that I asked (Two servers with inconsistent disk speed). I have a PowerEdge R510 server with a PERC H700 integrated RAID controller (call this Server B) that was built using eight disks with 3Gb/s bandwidth that I was comparing with an almost identical server (call this Server A) that was built using four disks with 6Gb/s bandwidth. Server A had much better I/O rates than Server B. Once I discovered the difference with the disks, I had Server A rebuilt with faster 6Gbps disks. Unfortunately this resulted in no increase in the performance of the disks. Expecting that there must be some other configuration difference between the servers, we took the 6Gbps disks out of Server A and put them in Server B. This also resulted in no increase in the performance of the disks. We now have two identical servers built, with the exception that one is built with six 6Gbps disks and the other with eight 3Gbps disks, and the I/O rates of the disks is pretty much identical. This suggests that there is some bottleneck other than the disks, but I cannot understand how Server B originally had better I/O that has subsequently been 'lost'. Comparative I/O information below, as measured by SQLIO. The same parameters were used for each test. It's not the actual numbers that are significant but rather the variations between systems. In each case D: is a 2 disk RAID 1 volume, and E: is a 4 disk RAID 10 volume (apart from the original Server A, where E: was a 2 disk RAID 0 volume). Server A (original setup with 6Gpbs disks) D: Read (MB/s) 63 MB/s D: Write (MB/s) 170 MB/s E: Read (MB/s) 68 MB/s E: Write (MB/s) 320 MB/s Server B (original setup with 3Gpbs disks) D: Read (MB/s) 52 MB/s D: Write (MB/s) 88 MB/s E: Read (MB/s) 112 MB/s E: Write (MB/s) 130 MB/s Server A (new setup with 3Gpbs disks) D: Read (MB/s) 55 MB/s D: Write (MB/s) 85 MB/s E: Read (MB/s) 67 MB/s E: Write (MB/s) 180 MB/s Server B (new setup with 6Gpbs disks) D: Read (MB/s) 61 MB/s D: Write (MB/s) 95 MB/s E: Read (MB/s) 69 MB/s E: Write (MB/s) 180 MB/s Can anybody suggest any ideas what is going on here? The drives in use are as follows: Dell Seagate F617N ST3300657SS 300GB 15K RPM SAS Dell Hitachi HUS156030VLS600 300GB 3.5 inch 15000rpm 6GB SAS Hitachi Hus153030vls300 300GB Server SAS Dell ST3146855SS Seagate 3.5 inch 146GB 15K SAS

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• kernel panic after LVM setup

  - by Manuel Sopena Ballesteros

  I broke my webserver... My setup is: VMWare ESXi environemt CPanel installed CentOS release 6.5 (Final) 4 CPUs 2G RAM 2x VM disks 100G each LVM system This was my previous storage settings (the server was working fine at this time): # df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_test01-lv_root 95G 1.4G 88G 2% / tmpfs 939M 0 939M 0% /dev/shm /dev/sdb1 99G 188M 94G 1% /tmp /dev/sda1 485M 54M 407M 12% /boot My web developer asked me to merge /tmp and / disks so this is what I did: Delete /dev/sdb1 partition using fdisk Create a new partition as LVM on /dev/sdb1 using fdisk Create a new physical volume -- pvcreate /dev/sdb1 Extend volume group -- vgextend /dev/sdb1 vg_test01 Extend logical volume -- lvextend -l +100%FREE /dev/vg_test01/lv_root Resize filesystem -- resize2fs /dev/vg_test01/lv_root This is the new configuration: # df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_test01-lv_root 213G 105G 97G 52% / tmpfs 939M 0 939M 0% /dev/shm /dev/sda1 485M 54M 407M 12% /boot /usr/tmpDSK 4.0G 145M 3.6G 4% /tmp Since I have the new settings my web server is throwing kernel panics quite often (around every 2 days). The message says: INFO: task <taskName>:<pid> blocked for more than 120 seconds. The list of process affected that I can see from the console are: mysqld queueprocd httpd suphp vmtoolsd loop0 auditd The only way I can fix this is reseting (cold reboot) the VM. I don't think it is a hardware issue as sar is not showing any bottleneck: Linux 2.6.32-431.3.1.el6.x86_64 (test01) 08/22/2014 _x86_64_ (4 CPU) 12:00:01 AM CPU %user %nice %system %iowait %steal %idle 12:10:01 AM all 26.86 0.01 0.98 0.57 0.00 71.57 12:20:01 AM all 1.78 0.02 1.03 0.08 0.00 97.09 12:30:01 AM all 26.34 0.02 0.85 0.05 0.00 72.74 12:40:01 AM all 27.12 0.01 1.11 1.22 0.00 70.54 12:50:01 AM all 1.59 0.02 0.94 0.13 0.00 97.32 01:00:01 AM all 26.10 0.01 0.77 0.04 0.00 73.07 01:10:01 AM all 27.51 0.01 1.16 0.14 0.00 71.18 01:20:01 AM all 1.80 0.07 1.06 0.08 0.00 96.99 01:30:01 AM all 26.19 0.01 0.78 0.05 0.00 72.96 01:40:01 AM all 26.62 0.02 0.87 0.05 0.00 72.45 01:50:02 AM all 1.35 0.01 0.87 0.02 0.00 97.75 02:00:01 AM all 26.11 0.02 0.69 0.02 0.00 73.17 02:10:01 AM all 26.73 0.02 0.89 0.14 0.00 72.21 02:20:01 AM all 1.45 0.01 0.92 0.04 0.00 97.58 02:30:01 AM all 26.59 0.01 1.06 0.03 0.00 72.31 02:40:01 AM all 26.27 0.01 0.72 0.05 0.00 72.95 02:50:01 AM all 0.86 0.01 0.50 0.09 0.00 98.53 03:00:01 AM all 25.61 0.02 0.39 0.03 0.00 73.96 03:10:01 AM all 26.30 0.08 0.66 0.14 0.00 72.82 03:20:01 AM all 0.81 0.01 0.51 0.04 0.00 98.63 03:30:02 AM all 26.15 0.02 0.53 0.07 0.00 73.24 03:40:01 AM all 26.06 0.01 0.47 0.04 0.00 73.42 03:50:01 AM all 0.96 0.02 0.51 0.03 0.00 98.48 Average: all 17.69 0.02 0.79 0.14 0.00 81.36 06:58:14 AM LINUX RESTART 07:00:01 AM CPU %user %nice %system %iowait %steal %idle 07:10:01 AM all 1.04 0.02 0.57 0.95 0.00 97.42 07:20:02 AM all 0.66 0.01 0.39 0.06 0.00 98.87 07:30:01 AM all 25.71 0.01 0.45 0.16 0.00 73.67 07:40:01 AM all 25.88 0.01 0.35 0.08 0.00 73.68 07:50:01 AM all 1.13 0.02 0.55 0.11 0.00 98.19 As you can see the server became unresponsive at 03.50 AM and I had to reset the VM at 06.58 AM to bring the website up again. I would appreciate any help/assistance to fix this issue. thank you very much

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• Need to increase nginx throughput to an upstream unix socket -- linux kernel tuning?

  - by Ben Lee

  I am running an nginx server that acts as a proxy to an upstream unix socket, like this: upstream app_server { server unix:/tmp/app.sock fail_timeout=0; } server { listen ###.###.###.###; server_name whatever.server; root /web/root; try_files $uri @app; location @app { proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto $scheme; proxy_set_header Host $http_host; proxy_redirect off; proxy_pass http://app_server; } } Some app server processes, in turn, pull requests off /tmp/app.sock as they become available. The particular app server in use here is Unicorn, but I don't think that's relevant to this question. The issue is, it just seems that past a certain amount of load, nginx can't get requests through the socket at a fast enough rate. It doesn't matter how many app server processes I set up, it doesn't even matter what the app is (tried it with a dummy app with just a single endpoint that returned an empty page with status 404). The bottleneck seems to be the socket, not the app. I'm getting a flood of these messages in the nginx error log: connect() to unix:/tmp/app.sock failed (11: Resource temporarily unavailable) while connecting to upstream Many requests result in status code 502, and those that don't take a long time to complete. The nginx write queue stat hovers around 1000. Anyway, I feel like I'm missing something obvious here, because this particular configuration of nginx and app server is pretty common, especially with Unicorn (it's the recommended method in fact). Are there any linux kernel options that needs to be set, or something in nginx? Any ideas about how to increase the throughput to the upstream socket? Something that I'm clearly doing wrong? Additional information on the environment: $ uname -a Linux app1 3.2.0-24-generic #39-Ubuntu SMP Mon May 21 16:52:17 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux $ ruby -v ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux] $ unicorn -v unicorn v4.3.1 $ nginx -V nginx version: nginx/1.2.1 built by gcc 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) TLS SNI support enabled Current kernel tweaks: net.core.rmem_default = 65536 net.core.wmem_default = 65536 net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.tcp_mem = 16777216 16777216 16777216 net.ipv4.tcp_window_scaling = 1 net.ipv4.route.flush = 1 net.ipv4.tcp_no_metrics_save = 1 net.ipv4.tcp_moderate_rcvbuf = 1 net.core.somaxconn = 8192 net.netfilter.nf_conntrack_max = 131072

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• Planning trunk capacity for multiple GbE switches

  - by wuckachucka

  Without measuring throughput (it's at the top of the list; this is just theoretical), I want to know the most standard method for trunking VLANs on multiple Gigabit (GbE) switches to a core Layer 3 GbE switch. Say you have three VLANs: VLAN10 (10.0.0.0/24) Servers: your typical Windows DC/file server, Exchange, and an Accounting/SQL server. VLAN20: (10.0.1.0/24) Sales: needs access to everything on VLAN10; doesn't need access to VLAN30 and vice-versa. VLAN20: (10.0.1.0/24) Support: needs access to everything on VLAN10; doesn't need access to VLAN20 and vice-versa. Here's how I think this should work in my head: Switch #1: Ports 2-20 are assigned to VLAN20; all the Sales workstations and printers are connected here. Optional 10GbE combo port #1 is trunked to L3 switch's 10 GbE combo port #1. Switch #2: Ports 2-20 are assigned to VLAN30; all the Support workstations and printers are connected here. Optional 10GbE combo port #1 is trunked to L3 switch's 10 GbE combo port #2. Core L3 switch: Ports 2-10 are assigned to VLAN10; all three servers are connected here. With a standard 10/100 x 24 switch, it'll usually come with one or two 1 GbE uplink ports; carrying over this logic to a 10/100/1000 x 24, the "optional" 10 GbE combo ports that most higher-end switches can get shouldn't really be an option. Keep in mind I haven't tested anything yet, I'm primarily moving in this direction for growth (don't want to buy 10/100 switches and have to replace those within a couple of years) and security (being able to control access between VLANs with L3 routing/packet filtering ACLs). Does this sound right? Do I really need the 10 GbE ports? It seems very non-standard and expensive, but it "feels" right when you think about 40 or 50 workstations trunking up to the L3 switch over 1 GbE standard ports. If say 20 workstations want to download a 10 GB image from the servers concurrently, wouldn't the trunk be the bottleneck? At least if the trunk was 10 GbE, you'd have 10x1GbE nodes being able to reach their theoretical max. What about switch stacking? Some of the D-Links I've been looking at have HDMI interfaces for stacking. As far as I know, stacking two switches creates one logical switch, but is this just for management I/O or does the switches use the (assuming it's HDMI 1.3) 10.2 Gbps for carrying data back and forth?

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