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SEARCH KEYWORD -- DATA SECURITY



  How Query Optimizer Works in RDBMS

In a previous post, we discussed how the various relational operators are implemented in relational database systems. If you have read that post, you probably still remember that there are a few alternative implementations for every operator. Thus, how should RDBMS determine which algorithm (or implementation) to use? Obviously, to optimize the performance for any query, RDBMS has to select the correct the algorithm based on the query. It would not be desirable to always use the same algori...

   DATABASE,DATABASE DESIGN,DATABASE OPTIMIZATION     2019-04-20 07:26:32

  Landing page optimization : Less is more

There is a question on Quora : Why doesn't Quora show interesting questions/answers on their landing page? Why is it this? not this? Quora's product manage gives his answer to this question, it's agreed by many users in this community. Here is his answer: The logged out homepage is pretty sparse now mostly because it hasn't been given much treatment since the initial product launch. But we have plans on redesigning it and testing different variations (some with less info on the page, some with...

   Landing page,Optimization,Principle     2012-11-03 01:50:07

  What Makes A Successful Cryptocurrency?

The cryptocurrency landscape today is a little bit of a maze. There seem to be countless cryptos available — thousands of them, by some estimates — and unless you’re particularly well versed in this technology, it can be difficult to tell what differentiates them. To cut through some of the confusion, we decided to take a closer look at cryptocurrencies. We won’t simply list the most prominent ones, the way so many sites already have. Instead, we’re going to look i...

   BITCOIN,CRYPTOCURRENCY     2020-08-25 05:13:22

  mysql – connection example

Mysql is a database, and to gain access to the data within C++ you will need to be able to “talk” to the database via queries (just like on the mysql command line interface e.g. select * from tablename), the connection process is very similar to the command line interface you will need to supply connection details as in hostname (localhost normally), username, password, database to use and also there are other details that you can pass e.g port number more information can be gained f...

   C++,Database,MySQL,Connection,Example     2011-10-29 00:42:10

  High performance web apps with C++

It is Christmas over here, and it is time of giving. So I decided to give something back to the community. I guess this is as old as web programming itself. Trying to create C++ web framework. If you search on the web, you can find dozen of guys that had exactly the same idea. I am not different. For one of the previous projects(discontinued now) I created simple web framework in C++. If you like to hack in C++, here it is. Code is provided as-is, as part of larger application. You can ex...

   C++,Web apps,Web framework     2012-01-08 10:06:48

  Designing Fun

What is “Fun?”“I’ll know it when I see it.”In 1964, in Jacobellis v. Ohio, the US Supreme Court needed to decide whether the state of Ohio could ban a film it called “obscene”—a concept people understood but were hard-pressed to define. Justice Potter Stewart, in his concurring opinion, wrote: “I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description; and perhaps I ...

   Design,Fun,Create,Define,Research     2011-09-19 13:35:12

  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

  How to read Haskell like Python

Have you ever been in the situation where you need to quickly understand what a piece of code in some unfamiliar language does? If the language looks a lot like what you’re comfortable with, you can usually guess what large amounts of the code does; even if you may not be completely familiar how all the language features work.For Haskell, this is a little more difficult, since Haskell syntax looks very different from traditional languages. But there's no really deep difference here; you j...

   Haskell,Python,Format,Like,Similarity     2011-11-15 08:45:39

  Finding selected checkbox items in a JSF dataTable

This is one of those problems that I couldn’t find a complete example for when I needed it, so hopefully this will save somebody else the extra time it took me to piece it together. We frequently need to have data tables in our UI, and allow the user to select a subset of those items for action. In JavaServer Faces, this means having a DataTable, each row having its own checkbox. But when the action is triggered, how to we find which items the user has selected. The first step is to ...

   JavaServer Faces,JSF,Datatable,Checkbox,Example     2012-01-03 03:02:46