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  • CSS tags/media queries for chrome on iPhone [migrated]

    - by Mick79
    So Chrome is here for iOS.. Hoorah! However now due to the different screen layout (no footer toolbar) it messes with the ability to make a perfect layout for iphone web pages. I have a site for my company that resided perfectly inside an iphone screen, no scrolling required, it looked like an app. However now that chrome is here (and wildly popular) with its different screen layout, sites that were sized for iphone safari now look odd. Is there, or will there be, ways to isolate out chrome from safari and give them different CSS?

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  • Which of the following relational database management systems would a company adopt (for migration), if any, MS Access, MS SQL Server or MySQL?

    - by Hassan Hagi
    Dear programmers, as part of my final year university project, I am conducting research into relational database management systems such as Microsoft Office Access 2007, Microsoft SQL Server 2008 and MySQL 5.1. The description does not need to be detailed however; I am trying to find empirical evidence and professional opinion/fact to determine which of the three databases are best suited for the required size of company (stated or unstated). OS: Microsoft windows (XP or newer) Please consider the following, but full details are not necessary: Memory management Migration Design constraints Integrity (data and others) Triggers User constraints Ease of use Performance Crash Recovery (not the operating system) Total Cost of Ownership (TCO) Also any info on Open source (to do with the three RDBMS) Thank you for your time and help. Hassan Hagi

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  • How to Design a Relational Database; PASS Precon Swag and it’s “Symbolism”

    - by drsql
    Update! 10 more books added to the cadre from my friends at Red-Gate. With less than a week to go, I am starting to pack up for Charlotte and PASS 2013. I love that it is in Charlotte this year so I can drive and bring along some goodies to give away. Books and toys mostly, a variety of which were chosen rather specifically for some manner of symbolism with a tie in to database design for the most part. (Okay, symbolism is perhaps a bit of a stretch, but I have tied everything, even the goofy stuff,...(read more)

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  • MySQL Multi-Aggregated Rows in Crosstab Queries

    MySQL's crosstabs contain aggregate functions on two or more fields, presented in a tabular format. In a multi-aggregate crosstab query, two different functions can be applied to the same field or the same function can be applied to multiple fields on the same (row or column) axis. Rob Gravelle shows you how to apply two different functions to the same field in order to create grouping levels in the row axis.

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  • MySQL Multi-Aggregated Rows in Crosstab Queries

    MySQL's crosstabs contain aggregate functions on two or more fields, presented in a tabular format. In a multi-aggregate crosstab query, two different functions can be applied to the same field or the same function can be applied to multiple fields on the same (row or column) axis. Rob Gravelle shows you how to apply two different functions to the same field in order to create grouping levels in the row axis.

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  • NEW CERTIFICATION: Oracle Certified Expert, Oracle Database 11g Release 2 SQL Tuning

    - by Brandye Barrington
    Oracle Certification announces the release of the new Oracle Certified Expert, Oracle Database 11g Release 2 SQL Tuning certification. This certification is designed forDevelopers, Database Administrators and SQL developers who are proficient at tuning efficient SQL statements. This certification covers topics on core elements such as: identifying and tuning inefficient SQL statements, using automatic SQL tuning, managing optimizer statistics on database objects, implementing partitioning and analyizing queries. Beta testing for the Oracle Database 11g Release 2: SQL Tuning exam (1Z1-117) is now underway and thus is available at the greatly discounted rate of $50 USD. Visit pearsonvue.com/oracle and register for exam 1Z1-117. You can get all preparation details on the Oracle Certification website, including exam objectives, number of questions, time allotments, and pricing. QUICK LINKS: Certification Track: Oracle Certified Expert, Oracle Database 11g Release 2 SQL Tuning Certification Exam: Oracle Database 11g Release 2: SQL Tuning (1Z0-117) Certification Website: About Beta Exams Register Now: Pearson VUE

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  • Enhance your Queries with Stored Functions

    HeidiSQL 4's Stored Routine Editor offers a user-friendly alternative to using a command-line interface to create and manage your stored procedures and functions. Today, we'll be learning how to take advantage of some useful native MySQL functions as well as use the editor to create our own custom functions.

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  • Queries regarding Geometry Shaders

    - by maverick9888
    I am dealing with geometry shaders using GL_ARB_geometry_shader4 extension. My code goes like : GLfloat vertices[] = { 0.5,0.25,1.0, 0.5,0.75,1.0, -0.5,0.75,1.0, -0.5,0.25,1.0, 0.6,0.35,1.0, 0.6,0.85,1.0, -0.6,0.85,1.0, -0.6,0.35,1.0 }; glProgramParameteriEXT(psId, GL_GEOMETRY_INPUT_TYPE_EXT, GL_TRIANGLES); glProgramParameteriEXT(psId, GL_GEOMETRY_OUTPUT_TYPE_EXT, GL_TRIANGLE_STRIP); glLinkProgram(psId); glBindAttribLocation(psId,0,"Position"); glEnableVertexAttribArray (0); glVertexAttribPointer(0, 3, GL_FLOAT, 0, 0, vertices); glDrawArrays(GL_TRIANGLE_STRIP,0,4); My vertex shader is : #version 150 in vec3 Position; void main() { gl_Position = vec4(Position,1.0); } Geometry shader is : #version 150 #extension GL_EXT_geometry_shader4 : enable in vec4 pos[3]; void main() { int i; vec4 vertex; gl_Position = pos[0]; EmitVertex(); gl_Position = pos[1]; EmitVertex(); gl_Position = pos[2]; EmitVertex(); gl_Position = pos[0] + vec4(0.3,0.0,0.0,0.0); EmitVertex(); EndPrimitive(); } Nothing is rendered with this code. What exactly should be the mode in glDrawArrays() ? How does the GL_GEOMETRY_OUTPUT_TYPE_EXT parameter will affect glDrawArrays() ? What I expect is 3 vertices will be passed on to Geometry Shader and using those we construct a primitive of size 4 (assuming GL_TRIANGLE_STRIP requires 4 vertices). Can somebody please throw some light on this ?

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  • Database Security: The First Step in Pre-Emptive Data Leak Prevention

    - by roxana.bradescu
    With WikiLeaks raising awareness around information leaks and the harm they can cause, many organization are taking stock of their own information leak protection (ILP) strategies in 2011. A report by IDC on data leak prevention stated: Increasing database security is one of the most efficient and cost-effective measures an organization can take to prevent data leaks. By utilizing the data protection, access control, account management, encryption, log management, and other security controls inherent in the database management system, entities can institute first-level control over the widest range of protected information. As a central repository for unstructured data, which is growing at leaps and bounds, the database should be the first layer providing information leakage protection. Unfortunately, most organizations are not taking sufficient steps to protect their databases according to a survey of the Independent Oracle User Group. For example, any operating system administrator or database administrator can access the all the data stored in the database in most organizations. Without any kind of auditing or monitoring. And it's not just administrators, database users can typically access the database with ad-hoc query tools from their desktop and by-pass any application level controls. Despite numerous regulations calling for controls to limit the powers of insiders, most organizations still put too many privileges in the hands of their employees. Time and time again these excess privileges have backfired. Internal agents were implicated in almost half of data breaches according to the Verizon Data Breach Investigations Report and the rate is rising. Hackers also took advantage of these excess privileges very successfully using stolen credentials and SQL injection attacks. But back to the insiders. Who are these insiders and why do they do it? In 2002, the U.S. Secret Service (USSS) behavioral psychologists and CERT information security experts formed the Insider Threat Study team to examine insider threat cases that occurred in US critical infrastructure sectors, and examined them from both a technical and a behavioral perspective. A series of fascinating reports has been published as a result of this work. You can learn more by watching the ISSA Insider Threat Web Conference. So as your organization starts to look at data leak prevention over the coming year, start off by protecting your data at the source - your databases. IDC went on to say: Any enterprise looking to improve its competitiveness, regulatory compliance, and overall data security should consider Oracle's offerings, not only because of their database management capabilities but also because they provide tools that are the first layer of information leak prevention. Learn more about Oracle Database Security solutions and get the whitepapers, demos, tutorials, and more that you need to protect data privacy from internal and external threats.

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  • SQL SERVER Introduction to Extended Events Finding Long Running Queries

    The job of an SQL Consultant is very interesting as always. The month before, I was busy doing query optimization and performance tuning projects for our clients, and this month, I am busy delivering my performance in Microsoft SQL Server 2005/2008 Query Optimization and & Performance Tuning Course. I recently read white paper about Extended [...]...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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  • Design pattern to handle queries using multiple models

    - by coderkane
    I am presented with a dilemma while trying to re-designing the class structure for my PHP/MySQL application to make it more elegant and conform it to the SOLID principle. The problem goes like this: Let as assume, there is an abstract class called person which has certain properties to define a generic person, such as name, age, date of birth etc. There are two classes, student, and teacher, that implements this abstract class. They add their own unique properties to it. I have designed all the three classes to include all the operational logic (details of which are not relevant in context of the question). Now, I need to create views/reports/data grids which contain details from multiple classes, for example, say, a list of all students doing projects in Chemistry mentored by a teacher whose name is the parameter to the query. This is just one example of a view, there are many different views in the application, which uses data from 3-4 tables, and each of them have multiple input parameters to generate them. Considering this particular example, I have written the relevant query using JOIN and the results are as expected and proper, now here is the dilemma: Keeping in mind the single responsibility principle, where should I keep this query? It does not belong to either Student class, or Teacher class or any other classes currently present. a) Should I create a new class, say dataView class, and design it as a MVC pattern and keep the query there? What about the other views? how do they fit in this architecture? b) Should I not keep the query in code at all, and make it DB View ? c) Am I completely wrong in the approach? If so what is the right approach? My considerations are as follows: a) should be easy to add new views later on if requirement comes, without having to copy-paste-modify code b) would like to make it as loosely coupled as possible so that if minor db structure changes happen, it does not break I did google searches on report design and OOP report generators, but all the result seem to focus on the visual design of the report rather than fetching the data. I have already taken care of the visual aspect of the report using MVC with html templates. I am sure this is a very fundamental problem with known solution, but I am somehow not able to find it (maybe searching with wrong keyword). Edit1: Modified the title to make it more relevant Edit2: The accepted answer got me thinking in the right direction and identify my design flaws, which eventually led me to find this question and the solution in Stack Overflow which gave me the detailed answer to clear the confusion.

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  • Document Link about Database Features on Exadata

    - by Bandari Huang
    DBFS on Exadata Exadata MAA Best Practices Series - Using DBFS on Exadata  (Internal Only) Oracle® DatabaseSecureFiles and Large Objects Developer's Guide 11g Release 2 (11.2) E18294-01 Configuring a Database for DBFS on Oracle Database Machine [ID 1191144.1] Configuring DBFS on Oracle Database Machine [ID 1054431.1] Oracle Sun Database Machine Setup/Configuration Best Practices [ID 1274318.1] - Verify DBFS Instance Database Initialization Parameters    DBRM on Exadata Exadata MAA Best Practices Series - Benefits and use cases with Resource Manager, Instance Caging, IORM  (Internal Only) Oracle® Database Administrator's Guide 11g Release 2 (11.2) E25494-02    

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  • Oracle Database In-Memory

    - by Mike.Hallett(at)Oracle-BI&EPM
    Normal 0 false false false EN-GB X-NONE X-NONE Larry Ellison unveiled the next major milestone in database technology, Oracle Database In-Memory, on June 10, 2014. Oracle Database In-Memory will be generally available in July 2014 and can be used with all hardware platforms on which Oracle Database 12c is supported. This option will accelerate database performance by orders of magnitude for analytics, data warehousing, and reporting while also speeding up online transaction processing (OLTP). It allows any existing Oracle Database-compatible application to automatically and transparently take advantage of columnar in-memory processing, without additional programming or application changes. Benefits Fast ad-hoc analytics without the need to pre-create indexes Completely transparent to existing applications Faster mixed workload OLTP No database size limit Industrial strength availability and security Robustness and maturity of Oracle Database 12c To find out more see Oracle Database In-Memory Comment from Rittman Mead on Oracle In-Memory Option Launch  ... and I will let you know how this unfolds in regards to advantages for OBI11g and Exalytics and Big Data over the coming months. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • #OOW 2012 : IaaS, Private Cloud, Multitenant Database, and X3H2M2

    - by Eric Bezille
    The title of this post is a summary of the 4 announcements made by Larry Ellison today, during the opening session of Oracle Open World 2012... To know what's behind X3H2M2, you will have to wait a little, as I will go in order, beginning with the IaaS - Infrastructure as a Service - announcement. Oracle IaaS goes Public... and Private... Starting in 2004 with Fusion development, Oracle Cloud was launch last year to provide not only SaaS Application, based on standard development, but also the underlying PaaS, required to build the specifics, and required interconnections between applications, in and outside of the Cloud. Still, to cover the end-to-end Cloud  Services spectrum, we had to provide an Infrastructure as a Service, leveraging our Servers, Storage, OS, and Virtualization Technologies, all "Engineered Together". This Cloud Infrastructure, was already available for our customers to build rapidly their own Private Cloud either on SPARC/Solaris or x86/Linux... The second announcement made today bring that proposition a big step further : for cautious customers (like Banks, or sensible industries) who would like to benefits from the Cloud value of "as a Service", but don't want their Data out in the Cloud... We propose to them to operate the same systems, Exadata, Exalogic & SuperCluster, that are providing our Public Cloud Infrastructure, behind their firewall, in a Private Cloud model. Oracle 12c Multitenant Database This is also a major announcement made today, on what's coming with Oracle Database 12c : the ability to consolidate multiple databases with no extra additional  cost especially in terms of memory needed on the server node, which is often THE consolidation limiting factor. The principle could be compare to Solaris Zones, where, you will have a Database Container, who is "owning" the memory and Database background processes, and "Pluggable" Database in this Database Container. This particular feature is a strong compelling event to evaluate rapidly Oracle Database 12c once it will be available, as this is major step forward into true Database consolidation with Multitenancy on a shared (optimized) infrastructure. X3H2M2, enabling the new Exadata X3 in-Memory Database Here we are :  X3H2M2 stands for X3 (the new version of Exadata announced also today) Heuristic Hierarchical Mass Memory, providing the capability to keep most if not all the Data in the memory cache hierarchy. Of course, this is the major software enhancement of the new X3 Exadata machine, but as this is a software, our current customers would be able to benefit from it on their existing systems by upgrading to the new release. But that' not the only thing that we did with X3, at the same time we have upgraded everything : the CPUs, adding more cores per server node (16 vs. 12, with the arrival of Intel E5 / Sandy Bridge), the memory with 512GB memory as well per node,  and the new Flash Fire card, bringing now up to 22 TB of Flash cache. All of this 4TB of RAM + 22TB of Flash being use cleverly not only for read but also for write by the X3H2M2 algorithm... making a very big difference compare to traditional storage flash extension. But what does those extra performances brings to you on an already very efficient system: double your performances compare to the fastest storage array on the market today (including flash) and divide you storage price x10 at the same time... Something to consider closely this days... Especially that we also announced the availability of a new Exadata X3-2 8th rack : a good starting point. As you have seen a major opening for this year again with true innovation. But that was not the only thing that we saw today, as before Larry's talk, Fujitsu did introduce more in deep the up coming new SPARC processor, that they are co-developing with us. And as such Andrew Mendelsohn - Senior Vice President Database Server Technologies came on stage to explain that the next step after I/O optimization for Database with Exadata, was to accelerate the Database at execution level by bringing functions in the SPARC processor silicium. All in all, to process more and more Data... The big theme of the day... and of the Oracle User Groups Conferences that were also happening today and where I had the opportunity to attend some interesting sessions on practical use cases of Big Data one in Finances and Fraud profiling and the other one on practical deployment of Oracle Exalytics for Data Analytics. In conclusion, one picture to try to size Oracle Open World ... and you can understand why, with such a rich content... and this only the first day !

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  • Entity Framework: Connecting to a mdf user database file via localDB during script execution

    - by Marko Apfel
    Problem If you run the “Generate database from model” wizard and execute the generated script the destination database could be the wrong one (for instance master of the SQL Server). Solution To use an own mdf attachable user database some connection information must specified during script execution. Execute your script opens the dialog “Connect to Server”. Press “Options” and go to the second tab “Connection Properties”. Select “Browse server” in the “Connect to database” dropdown box: Confirm the information dialog with “Yes”. In the following dialog you could choose your user database. Now the schema is created in the user database.

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  • MySQL maintenance - how to clear the buffer?

    - by Dougal
    We have a server running our web app (PHP / MySQL) which is SLOW. My predecessor says that: "We use to do database maintenance, which use to clear the buffer, cached and unwanted variables." And I wonder what on earth he means with that statement? Does he mean a simple optimize of the tables? Or the query cache? I understand MySQL but don't really know what he is describing. I would appreciate any pointers. Thanks.

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  • Parameterized StreamInsight Queries

    - by Roman Schindlauer
    The changes in our APIs enable a set of scenarios that were either not possible before or could only be achieved through workarounds. One such use case that people ask about frequently is the ability to parameterize a query and instantiate it with different values instead of re-deploying the entire statement. I’ll demonstrate how to do this in StreamInsight 2.1 and combine it with a method of using subjects for dynamic query composition in a mini-series of (at least) two blog articles. Let’s start with something really simple: I want to deploy a windowed aggregate to a StreamInsight server, and later use it with different window sizes. The LINQ statement for such an aggregate is very straightforward and familiar: var result = from win in stream.TumblingWindow(TimeSpan.FromSeconds(5))               select win.Avg(e => e.Value); Obviously, we had to use an existing input stream object as well as a concrete TimeSpan value. If we want to be able to re-use this construct, we can define it as a IQStreamable: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value)); The DefineStreamable API lets us define a function, in our case from a IQStreamable (the input stream) and a TimeSpan (the window length) to an IQStreamable (the result). We can then use it like a function, with the input stream and the window length as parameters: var result = avg(stream, TimeSpan.FromSeconds(5)); Nice, but you might ask: what does this save me, except from writing my own extension method? Well, in addition to defining the IQStreamable function, you can actually deploy it to the server, to make it re-usable by another process! When we deploy an artifact in V2.1, we give it a name: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value))     .Deploy("AverageQuery"); When connected to the same server, we can now use that name to retrieve the IQStreamable and use it with our own parameters: var averageQuery = myApp     .GetStreamable<IQStreamable<SourcePayload>, TimeSpan, double>("AverageQuery"); var result = averageQuery(stream, TimeSpan.FromSeconds(5)); Convenient, isn’t it? Keep in mind that, even though the function “AverageQuery” is deployed to the server, its logic will still be instantiated into each process when the process is created. The advantage here is being able to deploy that function, so another client who wants to use it doesn’t need to ask the author for the code or assembly, but just needs to know the name of deployed entity. A few words on the function signature of GetStreamable: the last type parameter (here: double) is the payload type of the result, not the actual result stream’s type itself. The returned object is a function from IQStreamable<SourcePayload> and TimeSpan to IQStreamable<double>. In the next article we will integrate this usage of IQStreamables with Subjects in StreamInsight, so stay tuned! Regards, The StreamInsight Team

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  • Is there an industry standard for systems registered user permissions in terms of database model?

    - by EASI
    I developed many applications with registered user access for my enterprise clients. In many years I have changed my way of doing it, specially because I used many programming languages and database types along time. Some of them not very simple as view, create and/or edit permissions for each module in the application, or light as access or can't access certain module. But now that I am developing a very extensive application with many modules and many kinds of users to access them, I was wondering if there is an standard model for doing it, because I already see that's the simple or the light way won't be enough.

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  • New technical whitepaper on Database-as-a-Service

    - by Javier Puerta
    High Availability Best Practices for Database Consolidation- The Foundation for Database-as-a-Service. An Oracle White Paper - April 2014 This paper provides MAA best practices for Database Consolidation using Oracle Multitenant. It describes standard HA architectures that are the foundation for DBaaS. It is most appropriate for a technical audience: Architects, Directors of IT and Database Administrators responsible for the consolidation and migration of traditional database deployments to DBaaS.  Recommended best practices are equally relevant to any platform supported by Oracle Database except where explicitly noted as being an optimization or an example that applies only to Oracle Engineered systems. 

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  • Which database to use for quickly and pygtk

    - by usher
    I'm writing application using quickly Pygtk and glade. this application should have database connection (such as MySQL) for reading and writing data from the local or outsourcing machine \ server. However, in my machine there is MySQL installed, but when releasing the app it sould be installed on another ubuntu machine, which may not have mysql and moreover not the same database with the required database name and structure.... So my questions are: Is it a good choice using mysql as database 1.2 If not what is? Is it posible to embeding mysql or other database program during the installation from ubuntu software center? 2.2 If it's posible: hwo(any tutorial?) Where to store secure data outside the mysql (or whatever) for conecting the database every time a user launch the application

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  • What are some ways people deploy relational database changes using Node.js? [closed]

    - by JamesEggers
    I've been diving more and more into Node.js and hosting services like Heroku and Nodejitsu recently and have been trying to figure out how to best deploy database changes for postgres or mysql. There are a few migration projects under npm that I can see; however, all seem to be really buggy or just not work. I currently manage the Monarch migration project on npm, but it's currently buggy itself and my experiences developing such utilities are in other, more procedural, languages. So what do people use to deploy changes to their databases on these environments? What has worked for people? I'm looking for a better understanding of what the current situation/process looks like.

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  • Queries barely over the Cost Threshold for Parallelism

    - by jchang
    I had discussed SQL Server parallelism in Oct 2010, with my thoughts on the best settings for: Cost Threshold for Parallelism (CTP) and Max Degrees of Parallelism (MAXDOP) in Parallelism Strategy and Comments . At the time, I had intended to follow up with detailed measurements. So now a mere 2 years later, here it is. The general thought was that CTP should be raised from the default value of 5, and MAXDOP should be changed from unrestricted, on modern systems with very many cores, and most especially...(read more)

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  • Using Subjects to Deploy Queries Dynamically

    - by Roman Schindlauer
    In the previous blog posting, we showed how to construct and deploy query fragments to a StreamInsight server, and how to re-use them later. In today’s posting we’ll integrate this pattern into a method of dynamically composing a new query with an existing one. The construct that enables this scenario in StreamInsight V2.1 is a Subject. A Subject lets me create a junction element in an existing query that I can tap into while the query is running. To set this up as an end-to-end example, let’s first define a stream simulator as our data source: var generator = myApp.DefineObservable(     (TimeSpan t) => Observable.Interval(t).Select(_ => new SourcePayload())); This ‘generator’ produces a new instance of SourcePayload with a period of t (system time) as an IObservable. SourcePayload happens to have a property of type double as its payload data. Let’s also define a sink for our example—an IObserver of double values that writes to the console: var console = myApp.DefineObserver(     (string label) => Observer.Create<double>(e => Console.WriteLine("{0}: {1}", label, e)))     .Deploy("ConsoleSink"); The observer takes a string as parameter which is used as a label on the console, so that we can distinguish the output of different sink instances. Note that we also deploy this observer, so that we can retrieve it later from the server from a different process. Remember how we defined the aggregation as an IQStreamable function in the previous article? We will use that as well: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value))     .Deploy("AverageQuery"); Then we define the Subject, which acts as an observable sequence as well as an observer. Thus, we can feed a single source into the Subject and have multiple consumers—that can come and go at runtime—on the other side: var subject = myApp.CreateSubject("Subject", () => new Subject<SourcePayload>()); Subject are always deployed automatically. Their name is used to retrieve them from a (potentially) different process (see below). Note that the Subject as we defined it here doesn’t know anything about temporal streams. It is merely a sequence of SourcePayloads, without any notion of StreamInsight point events or CTIs. So in order to compose a temporal query on top of the Subject, we need to 'promote' the sequence of SourcePayloads into an IQStreamable of point events, including CTIs: var stream = subject.ToPointStreamable(     e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e),     AdvanceTimeSettings.StrictlyIncreasingStartTime); In a later posting we will show how to use Subjects that have more awareness of time and can be used as a junction between QStreamables instead of IQbservables. Having turned the Subject into a temporal stream, we can now define the aggregate on this stream. We will use the IQStreamable entity avg that we defined above: var longAverages = avg(stream, TimeSpan.FromSeconds(5)); In order to run the query, we need to bind it to a sink, and bind the subject to the source: var standardQuery = longAverages     .Bind(console("5sec average"))     .With(generator(TimeSpan.FromMilliseconds(300)).Bind(subject)); Lastly, we start the process: standardQuery.Run("StandardProcess"); Now we have a simple query running end-to-end, producing results. What follows next is the crucial part of tapping into the Subject and adding another query that runs in parallel, using the same query definition (the “AverageQuery”) but with a different window length. We are assuming that we connected to the same StreamInsight server from a different process or even client, and thus have to retrieve the previously deployed entities through their names: // simulate the addition of a 'fast' query from a separate server connection, // by retrieving the aggregation query fragment // (instead of simply using the 'avg' object) var averageQuery = myApp     .GetStreamable<IQStreamable<SourcePayload>, TimeSpan, double>("AverageQuery"); // retrieve the input sequence as a subject var inputSequence = myApp     .GetSubject<SourcePayload, SourcePayload>("Subject"); // retrieve the registered sink var sink = myApp.GetObserver<string, double>("ConsoleSink"); // turn the sequence into a temporal stream var stream2 = inputSequence.ToPointStreamable(     e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e),     AdvanceTimeSettings.StrictlyIncreasingStartTime); // apply the query, now with a different window length var shortAverages = averageQuery(stream2, TimeSpan.FromSeconds(1)); // bind new sink to query and run it var fastQuery = shortAverages     .Bind(sink("1sec average"))     .Run("FastProcess"); The attached solution demonstrates the sample end-to-end. Regards, The StreamInsight Team

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  • Queries barely over the Cost Threshold for Parallelism

    - by jchang
    Previously I had discussed SQL Server parallelism, with my thoughts on the best settings for: Cost Threshold for Parallelism (CTP) and Max Degrees of Parallelism (MAXDOP) in Parallelism Strategy and Comments . At the time, I had intended to follow up with detailed measurements. So now a mere 2 years later, here it is. The general thought was that CTP should be raised from the default value of 5, and MAXDOP should be changed from unrestricted, on modern systems with very many cores, and most especially...(read more)

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  • Is it safe to set MySQL isolation to "Read Uncommitted" (dirty reads) for typical Web usage? Even with replication?

    - by Continuation
    I'm working on a website with typical CRUD web usage pattern: similar to blogs or forums where users create/update contents and other users read the content. Seems like it's OK to set the database's isolation level to "Read Uncommitted" (dirty reads) in this case. My understanding of the general drawback of "Read Uncommitted" is that a reader may read uncommitted data that will later be rollbacked. In a CRUD blog/forum usage pattern, will there ever be any rollback? And even if there is, is there any major problem with reading uncommitted data? Right now I'm not using any replication, but in the future if I want to use replication (row-based, not statement-based) will a "Read Uncommitted" isolation level prevent me from doing so? What do you think? Has anyone tried using "Read Uncommitted" on their RDBMS?

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