SEARCH KEYWORD -- Microsoft data


  MySQL Index Merge Optimization Practices

In production environment databases, it is often seen that some SQL where conditions include: equal condition on a normal index + primary key range query + order by limit Although using a normal index would be more efficient, the system chooses to use index merge instead in some cases. This article explores such index merge situations. Index Merge Official Introduction   The Index Merge access method retrieves rows with multiple range scans and merges their results into one. Generall...

   INDEX MERGE,MYSQL,PRIMARY INDEX,SECONDARY INDEX     2024-09-10 04:52:26

  MySQL index optimization

Problem description: We need to access a very big table which has 40 million records. In the table, id is the primary key and program_id is indexed. When executing a select query: select * from program_access_log where program_id between 1 and 4000 The above query executes very slowly, we thought it was because there were too many records in the table. So we added id in the where condition to limit the search so that each time only half a million records would be read. select * fr...

   MySQL,Index search, Partition     2012-12-26 13:14:20

  Create cron job on CentOS

These two days, I am building a website and deploying it on a VPS server which uses CentOS 5. I don't have cPanel or Plesk for my account, so I need to install and configure everything myself including Apache, PHP, MySQL and FTP server, also today's topic cron job. Since my website has a ranking algorithm to calculate the rankings of each link and update the ranking on database and I need to calculate the rankings every 5 minutes, so I think to use cron jobs. Here are what I have done which may ...

   cron job,crontab,CentOS,linux,php,example     2012-06-11 09:23:45

  Google's Business Operations in China Amid Antitrust Scrutiny

Google's journey in China has been complex, marked by strategic retreats and limited re-engagements. As of February 2025, while many of Google's consumer services remain inaccessible within mainland China, the company maintains a presence through specific business operations. However, Google's standing in China faces fresh challenges as the Chinese government recently launched an antitrust probe into the company's activities. This move comes amid rising tensions over trade and technology between...

   GOOGLE,BUSINESS,CHINA,ANTI-TRUST     2025-02-12 09:33:05

  2D Indoor CQB Robot Simulation

Program Design Purpose: The integration of robots in Close Quarters Battle (CQB) represents a significant advancement in modern military and law enforcement tactics. These robots, designed to navigate tight spaces, gather real-time intelligence, and engage threats, are invaluable assets in high-stakes scenarios. Our goal is to develop a 2D tactical board simulation system, similar to a computer game, that can load building floor blueprints, display CQB squad (robot) positions, enemy locations, ...

       2024-08-11 08:40:31

  Power Grid Simulation System 02 : FDI Power Outage Attack Case Study

We are excited to share that the Power Grid Simulation System we developed was used as part of one red team's targeted critical infrastructure system the international cyber exercise Crossed Swords 2024 which conducted in December 2024. In this article, we will introduce one power outage attack case study which use the Power Grid Simulation System as the demo platform for OT cyber security workshop. Project Design Purpose: This case study demonstrates using the Power Grid Simulation System as a...

       2025-01-11 07:35:45

  The Internet : from 1969-1974

Internet was born 43 years ago. There are some big events in the history of Internet development. In my opinion, most of the big events happened at the first five years, i.e, from 1969-1974.  1969 : ARPANETThe Advanced Research Projects Agency Network (ARPANET), was the world's first operational packet switching network and the core network of a set that came to compose the global Internet. The first ARPANET transmission was between Stanford Research Institute and UCLA on 29th, October 1969...

   Internet,History     2012-06-22 09:55:51

  Top 10 reasons to use a low-code platform

Generally, as the best coding platforms, low code includes low code app development, process development solutions and software development tools. IT users utilize low code solutions as a source of the required building blocks for the building of workflows and applications. The building blocks make it easier to assemble apps and workflows without requiring hand-coding. The growth of low-code platforms therefore levels business grounds by reducing the time spent in coding among other benefits.&nb...

   LOW CODE,PROGRAMMING     2021-02-18 19:43:49

  Tribute to Java On Successful Completion Of 20 Years

There is a great news for fans of Java that this week Java have completed its 20 years of success and that’s why it is celebrating its 20th anniversary. Java is a language which show legacy with the piece of technology and this is virtually important as the powerful programming methods and related machines are JVM (java virtual machine). SUCCESSFUL LAUNCH OF NEW VERSIONS Java developers are specially celebrating their event due to the huge success of their language and they get success a...

   Java software development, Java development services     2015-05-29 08:23:52

  Time-saving tips Linux users should know

As a programmer or system administrator, we have more chances of working on *nix platforms. It's tough experience when first start use *nix as we need to face a black screen without knowing what's behind it. Now, if we can have some resources to rely on, then we will find the beautify of *nix. They are fast, efficient and most importantly sexy. Below are some great tips for helping Linux users get used to Linux. This list is a bit long. So be patient. To get more information on a command mention...

   Linux,Tips     2013-09-03 22:30:48

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