Since version 7, RHEL and CentOS only have 64 bit versions. For some reasons, it’s better to run many Windows applications under 32 bit wine. Like How to Install Wine 32-bit on CentOS 7, this post introduce how to install 32-bit Wine on CentOS 8. Most of the mechanisms are similar yet there are differences….
How to replace strings in a column in a MySQL database table? For example, I would like to replace http://www.systutorials.com with https://www.systutorials.com in a content column of a table post. You may use a SQL statement as follows. update post set content = replace(content, ‘http://www.systutorials.com’, ‘https://www.systutorials.com’) where content like ‘%http://www.systutorials.com%’
How to show only N entries in the result of a select SQL query to MySQL? The select SQL query is: select * from qa_users; To limit the N entries (say N = 10), we can use the limit clause as follows. SELECT * FROM qa_users LIMIT 10; Note that it is for MySQL. For…
How to compare date in SQL? For example, the ‘users’ table has a column ‘loggin’ which is the date and time. How to find out the ‘users’ whose ‘loggin’ date is later than Jan 10, 2017? In SQL, dates can be compared using ‘’, ‘=‘. For the example described, the SQL statement could be: SELECT…
Currently, I wanna take Shark’s (Spark SQL) DDL and DML as an reference to design/implement SQLE’s DDL and DML. However, I cannot find its DDL and DML. I can only find several SQLs in Shark paper[1]. [1] shark paper – http://tab.d-thinker.org/showthread.php?tid=2585 Shark’s language is Hive QL. HQL’s DDL and DML can be found at Hive…
Facebook uses lots MySQL databases. Any information about how Facebook scales MySQL? Some information on the Web: MySQL at Facebook’s page https://www.facebook.com/MySQLatFacebook?filter=1 A post by Ryan Thiessen, Database Operations at Facebook on Quora: http://www.quora.com/Facebook-Engineering/How-does-Facebook-structure-MySQL-so-that-it-is-robust-and-scalable And more: http://mashable.com/2011/12/15/facebook-timeline-mysql/ http://gigaom.com/2011/12/06/facebook-shares-some-secrets-on-making-mysql-scale/ http://www.wired.com/wiredenterprise/2011/12/facebook-timeline-anatomy “A lot of people are surprised that for this shiny new thing for Facebook, we’re using…
After a server crash and restarting, MyBB reports a SQL Error as follows: MyBB SQL Error MyBB has experienced an internal SQL error and cannot continue. SQL Error: 145 – Table ‘./mybb/mybb_sessions’ is marked as crashed and should be repaired Query: SELECT * FROM mybb_sessions WHERE sid=’40021925bd0494ea31…’ AND ip=’x.x.x.x’ LIMIT 1 The dababase is MySQL….
Which are the consistency models used for distributed systems? Papers that survey the consistency models Robert C. Steinke and Gary J. Nutt. 2004. A unified theory of shared memory consistency. J. ACM 51, 5 (September 2004), 800-849. DOI=10.1145/1017460.1017464 http://doi.acm.org/10.1145/1017460.1017464 David Mosberger. 1993. Memory consistency models. SIGOPS Oper. Syst. Rev. 27, 1 (January 1993), 18-26. DOI=10.1145/160551.160553…
What are the SQL layer solution over NoSQL databases such as key/value stores? Phoenix: A SQL layer on HBase: https://github.com/forcedotcom/phoenix They also show some performance results: https://github.com/forcedotcom/phoenix/wiki/Performance F1 – The Fault-Tolerant Distributed RDBMS Supporting Google’s Ad Business: http://research.google.com/pubs/pub38125.html With F1, we have built a novel hybrid system that combines the scalability, fault tolerance, transparent sharding,…
What surprises are awaiting the tech world with .NET Core 2.1 Release in 2018? Technology is one of the most dynamic spheres these days. Every single year you will find a new version of an existing software and .NET Core is not an exception. The intentions of these upgradation is to make online activities seamless,…
Introduction In this tutorial, we will be learning as how to deploy .NET Core 2.0 MVC web application on Microsoft Public Cloud i.e. Microsoft Azure, using Microsoft Visual Studio 2017 v15.3 For novice Cloud developers, aspiring .NET / Cloud architects, and all other IT professionals associated with the .NET Core framework & Cloud computing, especially…
Solution is very important part of Dynamics CRM. In order to deploy your customization, solution is the only bridge which help you to achieve your goal. There are two types of solutions available in CRM: Managed and Unmanaged. Managed Solutions: This is the solutions that you can import and publish only. You neither export it nor you can…
In this post, asp.net development India based professionals will explain the best way to manage the Restful service using AngularJS. They are explaining the push and pull functionality available in Rest service in simple steps. Read the article to know more. In this Post I am going explain how we can manage the Restful service…
If your website uses a self-signed certificates, Chrome will show a warning every time and you need clicks to continue. In this post, I will introduce how to make Chrome accept self-signed certificates for sites on Linux. This post is made short on purpose and you need to search the Web and learn if you…
Benchmarks are important to understand the performance and quantitative and qualitative comparison of different systems. Many analytic frameworks, such as Hive, Impala and Shark, are designed and implemented these years and become fundamental software for processing big data. How to benchmark these big data analytic systems is an interesting problem. The Big Data Benchmark The…
We use tomcat as the container used for instructions in the post. 1) Download the driver mysql-connector-java-*.*.*-bin.jar and put it into WEB-INF/lib/, and remember to restart tomcat. 2) The example code as follows. String driverName=”com.mysql.jdbc.Driver”; String userName=”username”; String userPasswd=”password”; String dbName=”dbname”; String tableName=”tablename”; String url=”jdbc:mysql://localhost/”+dbName+”?user=”+userName+”&password=”+userPasswd; Class.forName(“com.mysql.jdbc.Driver”).newInstance(); Connection conn=DriverManager.getConnection(url); Statement statement = conn.createStatement(); String sql=”SELECT *…
Cosmos is “Microsoft’s internal data storage/query system for analyzing enormous amounts (as in petabytes) of data”. There is no paper/technical report about Cosmos published yet. I compiled a list of information about Cosmos on the Web as follows. What is Microsoft’s Cosmos service? by Yaron Y. Goland. Microsoft Cosmos: Petabytes perfectly processed perfunctorily by Seth…