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• SQL SERVER – Retrieve and Explore Database Backup without Restoring Database – Idera virtual databas

  - by pinaldave

  I recently downloaded Idera’s SQL virtual database, and tested it. There are a few things about this tool which caught my attention. My Scenario It is quite common in real life that sometimes observing or retrieving older data is necessary; however, it had changed as time passed by. The full database backup was 40 GB in size, and, to restore it on our production server, it usually takes around 16 to 22 minutes, depending on the load server that is usually present. This range in time varies from one server to another as per the configuration of the computer. Some other issues we used to have are the following: When we try to restore a large 40-GB database, we needed at least that much space on our production server. Once in a while, we even had to make changes in the restored database, and use the said changed and restored database for our purpose, making it more time-consuming. My Solution I have heard a lot about the Idera’s SQL virtual database tool.. Well, right after we started to test this tool, we found out that it really delivers what it promises. Using this software was very easy and we were able to restore our database from backup in less than 2 minutes, sparing us from the usual longer time of 16–22 minutes. The needful was finished in a total of 10 minutes. Another interesting observation is that there is no need to have an additional space for restoring the database. For complete database restoration, the single additional MB on the drive is not required anymore. We can use the database in the same way as our regular database, and there is no need for any additional configuration and setup. Let us look at the most relevant points of this product based on my initial experience: Quick restoration of the database backup No additional space required for database restoration virtual database has no physical .MDF or .LDF The database which is restored is, in fact, the backup file converted in the virtual database. DDL and DML queries can be executed against this virtually restored database. Regular backup operation can be implemented against virtual database, creating a physical .bak file that can be used for future use. There was no observed degradation in performance on the original database as well the restored virtual database. Additional T-SQL queries can be let off on the virtual database. Well, this summarizes my quick review. And, as I was saying, I am very impressed with the product and I plan to explore it more. There are many features that I have noticed in this tool, which I think can be very useful if properly understood. I had taken a few screenshots using my demo database afterwards. Let us see what other things this tool can do besides the mentioned activities. I am surprised with its performance so I want to know how exactly this feature works, specifically in the matter of why it does not create any additional files and yet, it still allows update on the virtually restored database. I guess I will have to send an e-mail to the developers of Idera and try to figure this out from them. I think this tool is very useful, and it delivers a high level of performance way more than what I expected. Soon, I will write a review for additional uses of SQL virtual database.. If you are using SQL virtual database in your production environment, I am eager to learn more about it and your experience while using it. The ‘Virtual’ Part of virtual database When I set out to test this software, I thought virtual database had something to do with Hyper-V or visualization. In fact, the virtual database is a kind of database which shows up in your SQL Server Management Studio without actually restoring or even creating it. This tool creates a database in SSMS from the backup of the same database. The backup, however, works virtually the same way as original database. Potential Usage of virtual database: As soon as I described this tool to my teammate, I think his very first reaction was, “hey, if we have this then there is no need for log shipping.” I find his comment very interesting as log shipping is something where logs are moved to another server. In fact, there are no updates on the database from log; I would rather compare it with Snapshot Replication. In fact, whatever we use, snapshot replicated database can be similarly used and configured with virtual database. I totally believe that we can use it for reporting purpose. In fact, after this database was configured, I think the uses of this tool are unlimited. I will have to spend some more time studying it and will get back to you. Click on images to see larger images. virtual database Console Harddrive Space before virtual database Setup Attach Full Backup Screen Backup on Harddrive Attach Full Backup Screen with Settings virtual database Setup – less than 60 sec virtual database Setup – Online Harddrive Space after virtual database Setup Point in Time Recovery Option – Timeline View virtual database Summary No Performance Difference between Regular DB vs Virtual DB Please note that all SQL Server MVP gets free license of this software. Reference: Pinal Dave (http://blog.SQLAuthority.com), Idera (virtual database) Filed under: Database, Pinal Dave, SQL, SQL Add-On, SQL Authority, SQL Backup and Restore, SQL Data Storage, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, SQLAuthority News, T SQL, Technology Tagged: Idera

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• Fitting it together, database, reporting, applications in C#

  - by alvonellos

  Introduction Preamble I was hesitant to post this, since it's an application whose intricate details are defined elsewhere, and answers may not be helpful to others. Within the past few weeks (I was actually going to write a blog post about this after I finished) I've discovered that the barrier I'm encountering is one that's actually quite common for newer developers. This question is not so much about a specific thing as it is about piecing those things together. I've searched the internet far and wide, and found many tutorials on how to create applications that are kind of similar to what I'm looking for. I've also looked at hiring another, more experienced, developer to help me along, but all I've gotten are unqualified candidates that don't have the experience necessary and won't take care of the client or project like I will. I'd rather have the project never transpire than to release a solution that is half-baked. I've asked professors at my school, but they've not turned up answers to my question. I'm an experienced developer, and I've written many applications that are -- very abstractly -- close to what I'm doing, but my experiences from those applications aren't giving me enough leverage to solve this particular problem. I just hope that posting this article isn't a mistake for me to write. Project Description I have a project I'm working on for a client that is a rewrite of an application, originally written in Foxpro 2.6 by someone before me, that performs some analysis (which, sadly, I'm not allowed to disclose as per of my employment contract) on financial data. One day, after a long talk between the client and I -- where he intimately described his frustrations with all the bugs I've been hacking out of this code for 6 months now -- he told me to just rewrite it and gave me a month to write a good 1/8 of this 65k LOC Foxpro monstrosity. this 65k line of code foxpro monstrosity. It'll take me a good 3 - 6 months to rewrite this software (I know things the original programmer did not, like inheritance) going as I am right now, but I'm quickly discovering that I'm going to need to use databases. Prior to this contract I didn't even know about foxpro, and so I've had to learn foxpro on the fly, write procedures and make modifications to the database. I've actually come to like it, and this project would be rewritten in Foxpro if it were still a supported language, because over the past few months, I've come to like the features of Foxpro that make it so easy to develop data-driven applications. I once perfomed an experiment, comparing C# to Foxpro. What took me 45 minutes in C# took me two in Foxpro, and I knew C# prior to Foxpro. I was hoping to leverage the power of C#, but it intimidates me that in foxpro, you can have one line of code and be using a database. Prior to this, I have never written any serious database development from scratch. All the applications that I've written are in a different league. They are either completely data-naive or data-naive enough that I can get away with not using a database through serialization or by designing algorithms that work with the data in a manner that is stateless, so there is no need to worry about databases. I've come to realize, very quickly, that serialization and my efficacy with data structures has been my crutch all these years that's prevented me from adventuring into databases, and has consequently hindered my success in real-world programming. Sure, I've written some database stuff in Perl and Python, and I've done forms and worked with relational databases and tables, I'm a wizard in Access and Excel (seriously) and can do just about anything, but it just feels unnatural writing SQL code in another language... I don't mind writing SQL, and I don't It's that bridge between the database and the program code that drives me absolutely bonkers. I hope I'm not the only one to think this, but it bothers me that I have to create statements like the following string sSql = "SELECT * from tablename" When there's really no reason for that kind of unchecked language binding between two languages and two API's. Don't get my wrong, SQL is great, but I don't like the idea that, when executing commands on a SQL database, that one must intermix database and application software, and there's no database independence, which means that different versions of different databases can break code. This isn't very nice. The nicest thing about Foxpro is the cohesiveness between programming language and database. It's so easy, and Foxpro makes it easy, because the tool just fits the task. I can see why so many developers have created a career with this language, because it lowered the barrier of entry to data-driven applications that so many businesses need. It was wonderful. For my purposes today, with the demands and need for community support, extensibility, and language features, Foxpro isn't a solution that I feel would be the right tool for the job. I'm also worried about working too heavy with the database, because I've seen data-driven .NET applications have issues with database caches, running out of memory, and objects in the database not being collected. (Memory leaks) And OH the queries. Which one, how, and why? There are a plethora of different ways that a database can be setup, I think I counted 5 or 6 different kinds of database applications alone that I can chose from. That is a great mountain for me to climb when I don't even know where to begin when it comes to writing data-driven applications. The problem isn't that I don't know SQL or that I don't know C#. I know both and have worked with both extensively. It's making them work together that's the problem, and it's something I've never done in C# before. Reports The client likes paper. The data needs to be printed out in a format that is extensible, layered, and easy to use. I have never done reporting before, and so this is a bit of a problem. From the data source comes crystal reports, and so there's a dependency on the database, from what I understand. Code reuse A large part of the design decision that I've gone through so far is to break the task of writing a piece of this software into routines and modular DLL's and so forth such that much of the code can be reused. For example, when I setup this database, I want to be able to reuse the same database code over and over again. I also want to make sure that when the day comes that another developer is here, that he/she will be able to pick up just where I left off. The quicker I develop these applications, the better off I am. Tasks & Goals In my project, I need to write routines that apply algorithms and look for predefined patterns in financial data. Additionally, I need to simulate trading based on predefined algorithms and data. Then I need to prepare reports on that data. Additionally, I need to have a way to change the code base for this application quickly and effectively, without hacking together some band-aid solution for a problem that really needs a trauma ward. Special Considerations The solution must be fast, run quickly on existing hardware, and not be too much of a pain to maintain and write. I understand that anything I write I'm married to -- I'm responsible for the things that I write because my reputation and livelihood is dependent on it. Do I really need a database? What about performance? Performance was such a big issue that I hand wrote a data structure that is capable of performing 2 billion operations, using a total of 4 gigs of memory in under 1/4 of a second using the standard core two duo processor. I could not find a similar, pre-written data structure in C# to perform this task. What setup do I use in terms of database? What about reporting? I'd prefer to have PDF's generated, but I'd like to be able to visually sketch those reports and then just have a ReportFactory of some sort, that when I pass some variables in, it just does that data. About Me I'm a lone developer for a small business in this area. This is the first time I've done this and I've never had the breadth and depth of my knowledge tested. I'm incredibly frustrated with this project because I feel incredibly overwhelmed with the task at hand. I'm looking for that entry level point where I can draw a line and say "this is what I need to do" Conclusion I may have not been clear enough on my post. I'm still new to this whole thing, and I've been doing my best to contribute back to the community that I've leached so much knowledge from. I'd be glad to edit my post and add more information if possible. I'm looking for a big-picture solution or design process that helps me get off the ground in this world of data-driven applications, because I have a feeling that it's going to be concentric to my entire career as a programmer for some time. Specifically, if you didn't get it from the rest of the post (I may not have been clear enough) I really need some guidance as to where to go in terms of the design decisions for this project. Some things that'll be useful will be a pro/con list for the different kinds of database projects available in VS2010. I've tried, but generating that list has been as hard as solving the problem itself... If you could walk a developer writing a data-driven application for the first time in C#, how would you do that? Where would you point them to?

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• SQLAuthority News – A Successful Performance Tuning Seminar at Pune – Dec 4-5, 2010

  - by pinaldave

  This is report to my third of very successful seminar event on SQL Server Performance Tuning. SQL Server Performance Tuning Seminar in Colombo was oversubscribed with total of 35 attendees. You can read the details over here SQLAuthority News – SQL Server Performance Optimizations Seminar – Grand Success – Colombo, Sri Lanka – Oct 4 – 5, 2010. SQL Server Performance Tuning Seminar in Hyderabad was oversubscribed with total of 25 attendees. You can read the details over here SQL SERVER – A Successful Performance Tuning Seminar – Hyderabad – Nov 27-28, 2010. The same Seminar was offered in Pune on December 4,-5, 2010. We had another successful seminar with lots of performance talk. This seminar was attended by 30 attendees. The best part of the seminar was that along with the our agenda, we have talked about following very interesting concepts. Deadlocks Detection and Removal Dynamic SQL and Inline Code SQL Optimizations Multiple OR conditions and performance tuning Dynamic Search Condition Building and Improvement Memory Cache and Improvement Bottleneck Detections – Memory, CPU and IO Beginning Performance Tuning on Production Parametrization Improving already Super Fast Queries Convenience vs. Performance Proper way to create Indexes Hints and Disadvantages I had great time doing the seminar and sharing my performance tricks with all. The highlight of this seminar was I have explained the attendees, how I begin doing performance tuning when I go for Performance Tuning Consultations.   Pinal Dave at SQL Performance Tuning Seminar SQL Server Performance Tuning Seminar Pinal Dave at SQL Performance Tuning Seminar Pinal Dave at SQL Performance Tuning Seminar SQL Server Performance Tuning Seminar SQL Server Performance Tuning Seminar This seminar series are 100% demo oriented and no usual PowerPoint talk. They are created from my experiences of various organizations for performance tuning. I am not planning any more seminar this year as it was great but I am booked currently for next 60 days at various performance tuning engagements. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQL Training, SQLAuthority News, T SQL, Technology

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• ???????/??????! Oracle Database 11g R2 ???????

  - by Yusuke.Yamamoto

  ????? ??:2010/11/17 ??:??????/?? 2009?9?? Oracle Database ?????Oracle Database 11g Release 2???????????1???????!??????????????????·??????????????????????????????????????????????????????????!??????????????????????????????????! Oracle Database 11g R2 ????Oracle Database 11g R2 ?????????? ????????? ????????????????? http://www.oracle.com/technology/global/jp/ondemand/otn-seminar/pdf/20101117_11gR2.pdf

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• Database model for keeping track of likes/shares/comments on blog posts over time

  - by gage

  My goal is to keep track of the popular posts on different blog sites based on social network activity at any given time. The goal is not to simply get the most popular now, but instead find posts that are popular compared to other posts on the same blog. For example, I follow a tech blog, a sports blog, and a gossip blog. The tech blog gets waaay more readership than the other two blogs, so in raw numbers every post on the tech blog will always out number views on the other two. So lets say the average tech blog post gets 500 facebook likes and the other two get an average of 50 likes per post. Then when there is a sports blog post that has 200 fb likes and a gossip blog post with 300 while the tech blog posts today have 500 likes I want to highlight the sports and gossip blog posts (more likes than average vs tech blog with more # of likes but just average for the blog) The approach I am thinking of taking is to make an entry in a database for each blog post. Every x minutes (say every 15 minutes) I will check how many likes/shares/comments an entry has received on all the social networks (facebook, twitter, google+, linkeIn). So over time there will be a history of likes for each blog post, i.e post 1234 after 15 min: 10 fb likes, 4 tweets, 6 g+ after 30 min: 15 fb likes, 15 tweets, 10 g+ ... ... after 48 hours: 200 fb likes, 25 tweets, 15 g+ By keeping a history like this for each blog post I can know the average number of likes/shares/tweets at any give time interval. So for example the average number of fb likes for all blog posts 48hrs after posting is 50, and a particular post has 200 I can mark that as a popular post and feature/highlight it. A consideration in the design is to be able to easily query the values (likes/shares) for a specific time-frame, i.e. fb likes after 30min or tweets after 24 hrs in-order to compute averages with which to compare against (or should averages be stored in it's own table?) If this approach is flawed or could use improvement please let me know, but it is not my main question. My main question is what should a database scheme for storing this info look like? Assuming that the above approach is taken I am trying to figure out what a database schema for storing the likes over time would look like. I am brand new to databases, in doing some basic reading I see that it is advisable to make a 3NF database. I have come up with the following possible schema. Schema 1 DB Popular Posts Table: Post post_id ( primary key(pk) ) url title Table: Social Activity activity_id (pk) url (fk) type (i.e. facebook,twitter,g+) value timestamp This was my initial instinct (base on my very limited db knowledge). As far as I under stand this schema would be 3NF? I searched for designs of similar database model, and found this question on stackoverflow, http://stackoverflow.com/questions/11216080/data-structure-for-storing-height-and-weight-etc-over-time-for-multiple-users . The scenario in that question is similar (recording weight/height of users overtime). Taking the accepted answer for that question and applying it to my model results in something like: Schema 2 (same as above, but break down the social activity into 2 tables) DB Popular Posts Table: Post post_id (pk) url title Table: Social Measurement measurement_id (pk) post_id (fk) timestamp Table: Social stat stat_id (pk) measurement_id (fk) type (i.e. facebook,twitter,g+) value The advantage I see in schema 2 is that I will likely want to access all the values for a given time, i.e. when making a measurement at 30min after a post is published I will simultaneous check number of fb likes, fb shares, fb comments, tweets, g+, linkedIn. So with this schema it may be easier get get all stats for a measurement_id corresponding to a certain time, i.e. all social stats for post 1234 at time x. Another thought I had is since it doesn't make sense to compare number of fb likes with number of tweets or g+ shares, maybe it makes sense to separate each social measurement into it's own table? Schema 3 DB Popular Posts Table: Post post_id (pk) url title Table: fb_likes fb_like_id (pk) post_id (fk) timestamp value Table: fb_shares fb_shares_id (pk) post_id (fk) timestamp value Table: tweets tweets__id (pk) post_id (fk) timestamp value Table: google_plus google_plus_id (pk) post_id (fk) timestamp value As you can see I am generally lost/unsure of what approach to take. I'm sure this typical type of database problem (storing measurements overtime, i.e temperature statistic) that must have a common solution. Is there a design pattern/model for this, does it have a name? I tried searching for "database periodic data collection" or "database measurements over time" but didn't find anything specific. What would be an appropriate model to solve the needs of this problem?

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• OBIEE 11.1.1 - (Updated) Best Practices Guide for Tuning Oracle® Business Intelligence Enterprise Edition (Whitepaper)

  - by Ahmed Awan

  Applies To: This whitepaper applies to OBIEE release 11.1.1.3, 11.1.1.5 and 11.1.1.6 Introduction: One of the most challenging aspects of performance tuning is knowing where to begin. To maximize Oracle® Business Intelligence Enterprise Edition performance, you need to monitor, analyze, and tune all the Fusion Middleware / BI components. This guide describes the tools that you can use to monitor performance and the techniques for optimizing the performance of Oracle® Business Intelligence Enterprise Edition components. Click to Download the OBIEE Infrastructure Tuning Whitepaper (Right click or option-click the link and choose "Save As..." to download this file) Disclaimer: All tuning information stated in this guide is only for orientation, every modification has to be tested and its impact should be monitored and analyzed. Before implementing any of the tuning settings, it is recommended to carry out end to end performance testing that will also include to obtain baseline performance data for the default configurations, make incremental changes to the tuning settings and then collect performance data. Otherwise it may worse the system performance.

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• EPM Infrastructure Tuning Guide v11.1.2.2 / 11.1.2.3

  - by Ahmed Awan

  Applies To: This edition applies to only 11.1.2.2, 11.1.2.3. One of the most challenging aspects of performance tuning is knowing where to begin. To maximize Oracle EPM System performance, all components need to be monitored, analyzed, and tuned. This guide describe the techniques used to monitor performance and the techniques for optimizing the performance of EPM components. TOP TUNING RECOMMENDATIONS FOR EPM SYSTEM: Performance tuning Oracle Hyperion EPM system is a complex and iterative process. To get you started, we have created a list of recommendations to help you optimize your Oracle Hyperion EPM system performance. This chapter includes the following sections that provide a quick start for performance tuning Oracle EPM products. Note these performance tuning techniques are applicable to nearly all Oracle EPM products such as Financial PM Applications, Essbase, Reporting and Foundation services. 1. Tune Operating Systems parameters. 2. Tune Oracle WebLogic Server (WLS) parameters. 3. Tune 64bit Java Virtual Machines (JVM). 4. Tune 32bit Java Virtual Machines (JVM). 5. Tune HTTP Server parameters. 6. Tune HTTP Server Compression / Caching. 7. Tune Oracle Database Parameters. 8. Tune Reporting And Analysis Framework (RAF) Services. 9. Tune Oracle ADF parameters. Click to Download the EPM 11.1.2.3 Infrastructure Tuning Whitepaper (Right click or option-click the link and choose "Save As..." to download this pdf file)

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• EPM 11.1.2 - EPM Infrastructure Tuning Guide v11.1.2.1

  - by Ahmed Awan

  Applies To: This edition applies to only 11.1.2, 11.1.2 (PS1). One of the most challenging aspects of performance tuning is knowing where to begin. To maximize Oracle EPM System performance, all components need to be monitored, analyzed, and tuned. This guide describe the techniques used to monitor performance and the techniques for optimizing the performance of EPM components. TOP TUNING RECOMMENDATIONS FOR EPM SYSTEM: Performance tuning Oracle Hyperion EPM system is a complex and iterative process. To get you started, we have created a list of recommendations to help you optimize your Oracle Hyperion EPM system performance. This chapter includes the following sections that provide a quick start for performance tuning Oracle EPM products. Note these performance tuning techniques are applicable to nearly all Oracle EPM products such as Financial PM Applications, Essbase, Reporting and Foundation services. 1. Tune Operating Systems parameters. 2. Tune Oracle WebLogic Server (WLS) parameters. 3. Tune 64bit Java Virtual Machines (JVM). 4. Tune 32bit Java Virtual Machines (JVM). 5. Tune HTTP Server parameters. 6. Tune HTTP Server Compression / Caching. 7. Tune Oracle Database Parameters. 8. Tune Reporting And Analysis Framework (RAF) Services. Click to Download the EPM 11.1.2.1 Infrastructure Tuning Whitepaper (Right click or option-click the link and choose "Save As..." to download this pdf file)

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• Examples of temporal database designs? [closed]

  - by miku

  I'm researching various database design for historical record keeping - because I would like to implement a prototypical web application that (excessively) tracks changes made by users and let them undo things, see revisions, etc. I'd love use mercurial or git as backend (with files as records) - since they already implement the kind of append-only changes I imagine. I tried git and dulwich (python git API) - and it went ok - but I was concerned about performance; Bi-temporal database design lets you store a row along with time periods, when this record was valid. This sure sound more performant than to operate on files on disk (as in 1.) - but I had little luck finding real-world examples (e.g. from open source projects), that use this kind of design and are approachable enough to learn from them. Revisions à la MediaWiki revisions or an extra table for versions, as in Redmine. The problem here is, that DELETE would take the whole history with it. I looked at NoSQL solutions, too. With a document oriented approach, it would be simple to just store the whole history of an entity within the document itself - which would reduce design plus implementation time in contrast to a RDBMS approach. However, in this case I'm a bit concerned about ACID-properties, which would be important in the application. I'd like ask about experiences about real-world and pragmatic designs for temporal data.

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• How to design database for tests in online test application

  - by Kien Thanh

  I'm building an online test application, the purpose of app is, it can allow teacher create courses, topics of course, and questions (every question has mark), and they can create tests for students and students can do tests online. To create tests of any courses for students, first teacher need to create a test pattern for that course, test pattern actually is a general test includes the number of questions teacher want it has, then from that test pattern, teacher will generate number of tests corresponding with number of students will take tests of that course, and every test for student will has different number of questions, although the max mark of test in every test are the same. Example if teacher generate tests for two students, the max mark of test will be 20, like this: Student A take test with 20 questions, student B take test only has 10 questions, it means maybe every question in test of student A only has mark is 1, but questions in student B has mark is 2. So 20 = 10 x 2, sorry for my bad English but I don't know how to explain it better. I have designed tables for: - User (include students and teachers account) - Course - Topic - Question - Answer But I don't know how to define associations between user and test pattern, test, question. Currently I only can think these: Test pattern table: name, description, dateStart, dateFinish, numberOfMinutes, maxMarkOfTest Test table: test_pattern_id And when user (is Student) take tests, I think i will have one more table: Result: user_id, test_id, mark but I can't set up associations among test pattern and test and question. How to define associations?

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• WebLogic Server Performance and Tuning: Part I - Tuning JVM

  - by Gokhan Gungor

  Each WebLogic Server instance runs in its own dedicated Java Virtual Machine (JVM) which is their runtime environment. Every Admin Server in any domain executes within a JVM. The same also applies for Managed Servers. WebLogic Server can be used for a wide variety of applications and services which uses the same runtime environment and resources. Oracle WebLogic ships with 2 different JVM, HotSpot and JRocket but you can choose which JVM you want to use. JVM is designed to optimize itself however it also provides some startup options to make small changes. There are default values for its memory and garbage collection. In real world, you will not want to stick with the default values provided by the JVM rather want to customize these values based on your applications which can produce large gains in performance by making small changes with the JVM parameters. We can tell the garbage collector how to delete garbage and we can also tell JVM how much space to allocate for each generation (of java Objects) or for heap. Remember during the garbage collection no other process is executed within the JVM or runtime, which is called STOP THE WORLD which can affect the overall throughput. Each JVM has its own memory segment called Heap Memory which is the storage for java Objects. These objects can be grouped based on their age like young generation (recently created objects) or old generation (surviving objects that have lived to some extent), etc. A java object is considered garbage when it can no longer be reached from anywhere in the running program. Each generation has its own memory segment within the heap. When this segment gets full, garbage collector deletes all the objects that are marked as garbage to create space. When the old generation space gets full, the JVM performs a major collection to remove the unused objects and reclaim their space. A major garbage collect takes a significant amount of time and can affect system performance. When we create a managed server either on the same machine or on remote machine it gets its initial startup parameters from $DOMAIN_HOME/bin/setDomainEnv.sh/cmd file. By default two parameters are set:     Xms: The initial heapsize     Xmx: The max heapsize Try to set equal initial and max heapsize. The startup time can be a little longer but for long running applications it will provide a better performance. When we set -Xms512m -Xmx1024m, the physical heap size will be 512m. This means that there are pages of memory (in the state of the 512m) that the JVM does not explicitly control. It will be controlled by OS which could be reserve for the other tasks. In this case, it is an advantage if the JVM claims the entire memory at once and try not to spend time to extend when more memory is needed. Also you can use -XX:MaxPermSize (Maximum size of the permanent generation) option for Sun JVM. You should adjust the size accordingly if your application dynamically load and unload a lot of classes in order to optimize the performance. You can set the JVM options/heap size from the following places:     Through the Admin console, in the Server start tab     In the startManagedWeblogic script for the managed servers     $DOMAIN_HOME/bin/startManagedWebLogic.sh/cmd     JAVA_OPTIONS="-Xms1024m -Xmx1024m" ${JAVA_OPTIONS}     In the setDomainEnv script for the managed servers and admin server (domain wide)     USER_MEM_ARGS="-Xms1024m -Xmx1024m" When there is free memory available in the heap but it is too fragmented and not contiguously located to store the object or when there is actually insufficient memory we can get java.lang.OutOfMemoryError. We should create Thread Dump and analyze if that is possible in case of such error. The second option we can use to produce higher throughput is to garbage collection. We can roughly divide GC algorithms into 2 categories: parallel and concurrent. Parallel GC stops the execution of all the application and performs the full GC, this generally provides better throughput but also high latency using all the CPU resources during GC. Concurrent GC on the other hand, produces low latency but also low throughput since it performs GC while application executes. The JRockit JVM provides some useful command-line parameters that to control of its GC scheme like -XgcPrio command-line parameter which takes the following options; XgcPrio:pausetime (To minimize latency, parallel GC) XgcPrio:throughput (To minimize throughput, concurrent GC ) XgcPrio:deterministic (To guarantee maximum pause time, for real time systems) Sun JVM has similar parameters (like  -XX:UseParallelGC or -XX:+UseConcMarkSweepGC) to control its GC scheme. We can add -verbosegc -XX:+PrintGCDetails to monitor indications of a problem with garbage collection. Try configuring JVM’s of all managed servers to execute in -server mode to ensure that it is optimized for a server-side production environment.

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• Tuning Red Gate: #4 of Some

  - by Grant Fritchey

  First time connecting to these servers directly (keys to the kingdom, bwa-ha-ha-ha. oh, excuse me), so I'm going to take a look at the server properties, just to see if there are any issues there. Max memory is set, cool, first possible silly mistake clear. In fact, these look to be nicely set up. Oh, I'd like to see the ANSI Standards set by default, but it's not a big deal. The default location for database data is the F:\ drive, where I saw all the activity last time. Cool, the people maintaining the servers in our company listen, parallelism threshold is set to 35 and optimize for ad hoc is enabled. No shocks, no surprises. The basic setup is appropriate. On to the problem database. Nothing wrong in the properties. The database is in SIMPLE recovery, but I think it's a reporting system, so no worries there. Again, I'd prefer to see the ANSI settings for connections, but that's the worst thing I can see. Time to look at the queries, tables, indexes and statistics because all the information I've collected over the last several days suggests that we're not looking at a systemic problem (except possibly not enough memory), but at the traditional tuning issues. I just want to note that, I started looking at the system, not the queries. So should you when tuning your environment. I know, from the data collected through SQL Monitor, what my top poor performing queries are, and the most frequently called, etc. I'm starting with the most frequently called. I'm going to get the execution plan for this thing out of the cache (although, with the cache dumping constantly, I might not get it). And it's not there. Called 1.3 million times over the last 3 days, but it's not in cache. Wow. OK. I'll see what's in cache for this database: SELECT  deqs.creation_time,         deqs.execution_count,         deqs.max_logical_reads,         deqs.max_elapsed_time,         deqs.total_logical_reads,         deqs.total_elapsed_time,         deqp.query_plan,         SUBSTRING(dest.text, (deqs.statement_start_offset / 2) + 1,                   (deqs.statement_end_offset - deqs.statement_start_offset) / 2                   + 1) AS QueryStatement FROM    sys.dm_exec_query_stats AS deqs         CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest         CROSS APPLY sys.dm_exec_query_plan(deqs.plan_handle) AS deqp WHERE   dest.dbid = DB_ID('Warehouse') AND deqs.statement_end_offset > 0 AND deqs.statement_start_offset > 0 ORDER BY deqs.max_logical_reads DESC ; And looking at the most expensive operation, we have our first bad boy: Multiple table scans against very large sets of data and a sort operation. a sort operation? It's an insert. Oh, I see, the table is a heap, so it's doing an insert, then sorting the data and then inserting into the primary key. First question, why isn't this a clustered index? Let's look at some more of the queries. The next one is deceiving. Here's the query plan: You're thinking to yourself, what's the big deal? Well, what if I told you that this thing had 8036318 reads? I know, you're looking at skinny little pipes. Know why? Table variable. Estimated number of rows = 1. Actual number of rows. well, I'm betting several more than one considering it's read 8 MILLION pages off the disk in a single execution. We have a serious and real tuning candidate. Oh, and I missed this, it's loading the table variable from a user defined function. Let me check, let me check. YES! A multi-statement table valued user defined function. And another tuning opportunity. This one's a beauty, seriously. Did I also mention that they're doing a hash against all the columns in the physical table. I'm sure that won't lead to scans of a 500,000 row table, no, not at all. OK. I lied. Of course it is. At least it's on the top part of the Loop which means the scan is only executed once. I just did a cursory check on the next several poor performers. all calling the UDF. I think I found a big tuning opportunity. At this point, I'm typing up internal emails for the company. Someone just had their baby called ugly. In addition to a series of suggested changes that we need to implement, I'm also apologizing for being such an unkind monster as to question whether that third eye & those flippers belong on such an otherwise lovely child.

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• (Database Design - products attributes): What is better option for product attribute database design

  - by meyosef

  Hi, I new in database design. What is better option for product attribute database design for cms?(Please suggest other options also). option 1: 1 table products{ id product_name color price attribute_name1 attribute_value1 attribute_name2 attribute_value2 attribute_name3 attribute_value3 } option 2: 3 tables products{ id product_name color price } attribute{ id name value } products_attribute{ products_id attribute_id } Thanks, Yosef

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• Tuning Red Gate: #5 of Multiple

  - by Grant Fritchey

  In the Tuning Red Gate series I've shown you how to look at a current load on the system and how to drill down to look at historical analysis of the system. I've also shown how you can see the top queries and other information from the current status of the system. I have one more thing I can show you before we need to start fixing things and showing how that affects the data collected, historical moments in time. For example, back in Post #3 I was looking at some spikes in some of the monitored resources that were taking place a couple of weeks back in time. Once I identify a moment in time that I'm interested in, I can go back to the first page of Monitor, Global Overview, and click on the icon: From this you can select the date and time you're interested in. For example, I saw some serious CPU queues last week: This then rolls back the time for all the information that's available to the Global Overview and the drill down to the server and the SQL Server instance there. This then allows me to look at the Top Queries running at this point, sort them by CPU and identify what was potentially the query that was causing the problem right when I saw the CPU queuing This ability to correlate a moment in time with the information available to you in the Analysis window makes for an excellent tool to investigate your systems going backwards in time. It really makes a huge difference in your knowledge. It's not enough to know that something happened at a particular time. You need to know what it was that was occurring. Remember, the key to tuning your systems is having enough knowledge about them. I'll post more on Tuning Red Gate as soon as I can get some queries rewritten. I'm working on that.

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• Database Vault 11gR2 11.2.0.1 Certified with Oracle E-Business Suite

  - by Steven Chan

  Oracle Database Vault allows security administrators to protect a database from privileged account access to application data.  Database objects can be placed in protected realms, which can be accessed only if a specific set of conditions are met.  Oracle Database Vault 11gR2 11.2.0.1 is now certified with Oracle E-Business Suite Release 11i and 12.You can now enable Database Vault 11gR2 on your existing E-Business Suite 11.2.0.1 Database instance.  If you already have DB Vault 10gR2 or 11gR1 enabled in your E-Business Suite environment, you can now upgrade to the 11gR2 Database.  We also support EBS patching with Database Vault 11.2.0.1 enabled. Our DB Vault realm creation and grants-related scripts have been updated to reduce patching downtimes.

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• Help With Database Layout

  - by three3

  Hello everyone, I am working on a site similar to Craigslist where users can make postings and sell items in different cities. One difference between my site and Craigslist will be you will be able to search by zip code instead of having all of the cities listed on the page. I already have the ZIP Code database that has all of the city, state, latitude, longitude, and zip code info for each city. Okay, so to dive into what I need done and what I need help with: 1.) Although I have the ZIP Code database, it is not setup perfectly for my use. (I downloaded it off of the internet for free from http://zips.sourceforge.net/) 2.) I need help setting up my database structure (Ex: How many different tables should I use and how should I link them) I will be using PHP and MySQL. These our my thoughts so far on how the database can be setup: (I am not sure if this will work though.) Scenario: Someone goes to the homepage and it will tell them, "Please enter your ZIP Code.". If they enter "17241" for example, this ZIP Code is for a city named Newville located in Pennsylvania. The query would look like this with the current database setup: SELECT city FROM zip_codes WHERE zip = 17241; The result of the query would be "Newville". The problem I see here now is when they want to post something in the Newville section of the site, I will have to have an entire table setup just for the Newville city postings. There are over 42,000 cities which means I would have to have over 42,000 tables (one for each city) so that would be insane to have to do it that way. One way I was thinking of doing it was to add a column to the ZIP Code database called "city_id" which would be a unique number assigned to each city. So for example, the city Newville would have a city_id of 83. So now if someone comes and post a listing in the city Newville I would only need one other table. That one other table would be setup like this: CREATE TABLE postings ( posting_id INT NOT NULL AUTO_INCREMENT, for_sale LONGTEXT NULL, for_sale_date DATETIME NULL, for_sale_city_id INT NULL, jobs LONGTEXT NULL, jobs_date DATETIME NULL, jobs_city_id INT NULL, PRIMARY KEY(posting_id) ); (The for_sale and job_ column names are categories of the types of postings users will be able to list under. There will be many more categories than just those two but this is just for example.) So now when when someone comes to the website and they are looking for something to buy and not sell, they can enter their ZIP Code, 17241, for example, and this is the query that will run: SELECT city, city_id FROM zip_codes WHERE zip = 17241; //Result: Newville 83 (Please note that I will be using PHP to store the ZIP Code the user enters in SESSIONS and Cookies to remember them throughout the site) Now it will tell them, "Please choose your category.". If they choose the category "Items For Sale" then this is the query to run and sort the results: SELECT posting_id, for_sale, for_sale_date FROM postings WHERE for_sale_city_id = $_SESSION['zip_code']; Will this work? So now my question to everyone is will this work? I am pretty sure it will but I do not want to set this thing up and realize I overlooked something and have to start from all over from scratch. Any opinions and ideas are welcomed and I will listen to anyone who has some thoughts. I really appreciate the help in advance :D

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• EPM 11.1.1 - EPM Infrastructure Tuning Guide v11.1.1.3

  - by Ahmed Awan

  This edition applies to EPM 9.3.1, 11.1.1.1, 11.1.1.2 & 11.1.1.3 only. INTRODUCTION:One of the most challenging aspects of performance tuning is knowing where to begin. To maximize Oracle EPM System performance, all components need to be monitored, analyzed, and tuned. This guide describe the techniques used to monitor performance and the techniques for optimizing the performance of EPM components. Click to Download the EPM 11.1.1.3 Infrastructure Tuning Whitepaper (Right click or option-click the link and choose "Save As..." to download this file)

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• Server configurations for hosting MySQL database

  - by shyam

  I have a web application which uses a MySQL database hosted on a virtual server. I've been using this server when I started the application and when the database was really small. Now it has grown and the server is not able to handle the db, causing frequent db errors. I'm planning to get a server and I need suggestions for that. Like I said, the db is now 9 GB, and is growing considerably fast. There are a number of tables with millions of rows, which are frequently updated and queried. The most frequent error the db shows is Lock wait timeout exceeded. Previously there used to be "The total number of locks exceeds the lock table size" errors too, but I could avoid it by increasing Innodb buffer pool size. Please suggest what configurations should I look for in the server I should buy. I read somewhere that the db should ideally have a buffer pool size greater than the size of its data, so in my case I guess I'd need memory gt 9 GB. What other things should I look for in the server? Just tell me if I should give you more info about the

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• Database Memory :: MySql Innodb how much storage memory allocation for empty field vs not empty fie

  - by Yosef

  Hi, I new in database, and dont know how and when mysql allocate memory space. In MySql Innodb how much storage memory allocation for empty field (no string inserted) vs not empty field? Other form of my question: When memory allocated space In MySql Innodb for varchar/text field in time of table creation or when data inserted inside field? Thank you, Yosef

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• SQL SERVER Retrieve and Explore Database Backup without Restoring Database Idera virtual database

  I recently downloaded Ideras SQL virtual database, and tested it. There are a few things about this tool which caught my attention.My ScenarioIt is quite common in real life that sometimes observing or retrieving older data is necessary; however, it had changed as time passed by. The full database backup was 40 GB in size, [...]...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Transportable Database 11gR2 Certified with E-Business Suite

  - by Steven Chan

  Platform migration is the process of moving a database from one operating system platform to a different operating system platform. You might wish to migrate your E-Business Suite database to create testing instances, experiment with new architectures, perform benchmarks, or prepare for actual platform changes in your production environment. Database migration across platforms of the same "endian" format (byte ordering) using the Transportable Database (TDB) process is now certified with Oracle Database 11gR2 (11.2.0.1) for:Oracle E-Business Suite Releases 11i (11.5.10.2) Oracle E-Business Suite Release 12.0.4 or higherOracle E-Business Suite Release 12.1.1 or higherThis EBS database migration process was previously certified only for 10gR2 and 11gR1.

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• Database Trends & Applications column: Database Benchmarking from A to Z

  - by KKline

  Have you heard of the monthly print and web magazine Database Trends & Applications (DBTA)? Did you know I'm the regular columnist covering SQL Server ? For the past six months, I've been writing a series of articles about database benchmarking culminating in the latest article discussing my three favorite database benchmarking tools: the free, open-source HammerDB, the native SQL Server Distributed Replay Utility, and the commercial Benchmark Factory from Dell / Quest Software. Wondering what...(read more)

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• Need help tuning Mysql and linux server

  - by Newtonx

  We have multi-user application (like MailChimp,Constant Contact) . Each of our customers has it's own contact's list (from 5 to 100.000 contacts). Everything is stored in one BIG database (currently 25G). Since we released our product we have the following data history. 5 years of data history : - users/customers (200+) - contacts (40 million records) - campaigns - campaign_deliveries (73.843.764 records) - campaign_queue ( 8 millions currently ) As we get more users and table records increase our system/web app is getting slower and slower . Some queries takes too long to execute . SCHEMA Table contacts --------------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------------+------------------+------+-----+---------+----------------+ | contact_id | int(10) unsigned | NO | PRI | NULL | auto_increment | | client_id | int(10) unsigned | YES | | NULL | | | name | varchar(60) | YES | | NULL | | | mail | varchar(60) | YES | MUL | NULL | | | verified | int(1) | YES | | 0 | | | owner | int(10) unsigned | NO | MUL | 0 | | | date_created | date | YES | MUL | NULL | | | geolocation | varchar(100) | YES | | NULL | | | ip | varchar(20) | YES | MUL | NULL | | +---------------------+------------------+------+-----+---------+----------------+ Table campaign_deliveries +---------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------+------------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | newsletter_id | int(10) unsigned | NO | MUL | 0 | | | contact_id | int(10) unsigned | NO | MUL | 0 | | | sent_date | date | YES | MUL | NULL | | | sent_time | time | YES | MUL | NULL | | | smtp_server | varchar(20) | YES | | NULL | | | owner | int(5) | YES | MUL | NULL | | | ip | varchar(20) | YES | MUL | NULL | | +---------------+------------------+------+-----+---------+----------------+ Table campaign_queue +---------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------+------------------+------+-----+---------+----------------+ | queue_id | int(10) unsigned | NO | PRI | NULL | auto_increment | | newsletter_id | int(10) unsigned | NO | MUL | 0 | | | owner | int(10) unsigned | NO | MUL | 0 | | | date_to_send | date | YES | | NULL | | | contact_id | int(11) | NO | MUL | NULL | | | date_created | date | YES | | NULL | | +---------------+------------------+------+-----+---------+----------------+ Slow queries LOG -------------------------------------------- Query_time: 350 Lock_time: 1 Rows_sent: 1 Rows_examined: 971004 SELECT COUNT(*) as total FROM contacts WHERE (contacts.owner = 70 AND contacts.verified = 1); Query_time: 235 Lock_time: 1 Rows_sent: 1 Rows_examined: 4455209 SELECT COUNT(*) as total FROM contacts WHERE (contacts.owner = 2); How can we optimize it ? Queries should take no more than 30 secs to execute? Can we optimize it and keep all data in one BIG database or should we change app's structure and set one single database to each user ? Thanks

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• Query Tuning Mastery at PASS Summit 2012: The Video

  - by Adam Machanic

  An especially clever community member was kind enough to reverse-engineer the video stream for me, and came up with a direct link to the PASS TV video stream for my Query Tuning Mastery: The Art and Science of Manhandling Parallelism talk, delivered at the PASS Summit last Thursday. I'm not sure how long this link will work , but I'd like to share it for my readers who were unable to see it in person or live on the stream. Start here. Skip past the keynote, to the 149 minute mark. Enjoy!...(read more)

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• Query Tuning Mastery at PASS Summit 2012: The Video

  - by Adam Machanic

  An especially clever community member was kind enough to reverse-engineer the video stream for me, and came up with a direct link to the PASS TV video stream for my Query Tuning Mastery: The Art and Science of Manhandling Parallelism talk, delivered at the PASS Summit last Thursday. I'm not sure how long this link will work , but I'd like to share it for my readers who were unable to see it in person or live on the stream. Start here. Skip past the keynote, to the 149 minute mark. Enjoy!...(read more)

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