Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- database

  Understanding database, instance and schema in Oracle database

Oracle database is the most popular database system among enterprises. To start working on Oracle database, some concepts must be understood first. They include database, instance, schema and user etc. And among these concepts, some have different meanings from those in other database systems such as MS SQL, MySQL, DB2. On the web, there are already some good posts which explain different concepts such as Ask Tom's database vs instances, Difference between database vs user vs schema. In this pos...

   DIFFERENCE,DATABASE,ORACLE DATABASE,INSTANCE,SCHEMA,USER     2016-12-14 23:30:56

  Application vs Database Programming

A few years ago, I had a problem.  A database routine for processing bulk payments for LedgerSMB that was humming along in my test cases was failing when tested under load with real data prior to implementation.  Some testing showed that while it ran fine with small numbers of inputs, it eventually slowed way down as the number of inputs rose.  Andrew Sullivan, who was also on the project through a different company, suggested it was something called a "cache miss" because I...

   Application Programming,Database programming,Comparison,Difference     2012-03-04 12:08:35

  Unknown system variable 'query_cache_size' in DbVisualizer while accessing MySQL

DbVisualizer is a very popular GUI application to view the data stored on a database. It supports various databases such as Oracle, MySQL etc. It relies on different database drivers to connect to the database server and access the data stored there.  In this post, we will try to solve one problem when accessing the latest MySQL database(8.0+) through DbVisualizer. MySQL database starting from 8.0 has lots of changes which may not be compatible with old version of software or libraries whic...

   MYSQL,MYSQL 8,DBVISUALIZER,QUERY_CACHE_SIZE     2018-06-30 03:48:17

  Work with MySQL character set and collation

For non-English websites, they often have to deal with character set and collation if they want to store data to and read data from databases with other languages. Character set tells the database which kind of character encoding scheme to use to store or read data, collation can be simply understood as a subset of character set, it tells the database how to sort data. We talk about working with character set and collation of MySQL today.  In MySQL, if we want to store Chinese, Japanese or ...

   MySQL,character set,collation,Chinese,question mark     2012-06-17 07:07:28

  Oracle database to execute multiple statements at command line

Oracle database is now a mature and popular RDBMS which is used by lots of enterprises. With its evolution, many utilities and applications are developed around it as well. Now Oracle database also provides cloud support. As a DBA, managing Oracle database is daily routine work and some tools may be used frequently. One of them is sqlplus, the command line tool for executing SQL command. sqlplus is installed while the Oracle database is installed. To start sqlplus, one just needs to open a termi...

   ORACLE,ORACLE DATABASE,SQLPLUS     2016-12-09 20:11:28

  Three things you should never put in your database

As I've said in a few talks, the best way to improve your systems is by first not doing "dumb things". I don't mean you or your development staff is "dumb", it's easy to overlook the implications of these types of decisions and not realize how bad they are for maintainability let alone scaling. As a consultant I see this stuff all of the time and I have yet to ever see it work out well for anyone. Images, files, and binary data Your database supports BLOBs so it must be a good idea to shove ...

   Database,BLOB,Log,Image     2012-05-02 04:44:25

  20 Database Design Best Practices

Use well defined and consistent names for tables and columns (e.g. School, StudentCourse, CourseID ...).Use singular for table names (i.e. use StudentCourse instead of StudentCourses). Table represents a collection of entities, there is no need for plural names.Don’t use spaces for table names. Otherwise you will have to use ‘{‘, ‘[‘, ‘“’ etc. characters to define tables (i.e. for accesing table Student Course you'll write “Student Cour...

   Database design,20 tips,Well defined name,Design pattern     2012-02-07 12:10:48

  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

  Twitter user database is hacked

According to Sina Tech, One hacker from Islamic Republic of Mauritania claimed today that he had acquired Twitter's entire user database and he shared over 15000 user account information on file sharing website Zippyshare.These information include the name of each account on Twitter, username and access tokens of third-party applications which have access to their Twitter accounts(such as Instagram or HootSuite).Twitter has yet to comment on the matter, but the company sent messages urging ...

   Twitter,Hacker,Access token     2013-08-20 10:49:44

  Cache Reheating - Not to be Ignored

An important aspect to keep in mind with databases is the cost of cache reheating after a server restart. Consider the following diagram which shows several cache servers (e.g., memcached) in front of a database server.This sort of setup is common and can work quite well when appropriate; it removes read load from the database and allows more RAM to be utilized for scaling (when the database doesn’t scale horizontally). But what happens if all the cache servers restart at the same time, s...

   Database,Cost,Cache reheating,Advice     2011-09-21 09:47:29

RECENT