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DB/RDB

• Stored Procedure

  DB/RDB 2020. 4. 11. 22:14

  1. Overview A stored procedure is a prepared SQL code that you can save, so the code can be reused over and over again. So if you have an SQL query that you write over and over again, save it as a stored procedure, and then just call it to execute it. You can also pass parameters to a stored procedure so that the stored procedure can act based on the parameter value(s) that is passed. 1.1 Define..

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• Comparison between MSSQL, Oracle, PostgreSQL, and MySQL

  DB/RDB 2020. 4. 11. 01:49

  1. Overview Name Microsoft SQL Server Oracle PostgreSQL MySQL Description Microsofts relational DBMS Widely used RDBMS Widely used open-source RDBMS Widely used open-source RDBMS Primary database model Relational DBMS Relational DBMS Relational DBMS Relational DBMS Secondary database models Document store Graph DBMS Document store Graph DBMS RDF store Document store Document store DB-Engines Ran..

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• PostgreSQL

  DB/RDB 2020. 4. 10. 23:11

  1. Overview PostgreSQL is a general-purpose and object-relational database management system, the most advanced open source database system. PostgreSQL was developed based on POSTGRES 4.2 at Berkeley Computer Science Department, University of California. PostgreSQL was designed to run on UNIX-like platforms. However, PostgreSQL was then also designed to be portable so that it could run on variou..

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• Database Cursor

  DB/RDB 2020. 2. 24. 01:53

  1. Overview In computer science, a database cursor is a control structure that enables traversal over the records in a database. Cursors facilitate subsequent processing in conjunction with the traversal, such as retrieval, addition, and removal of database records. The database cursor characteristic of traversal makes cursors akin to the programming language concept of an iterator. 2. Descripti..

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• Trigger

  DB/RDB 2020. 2. 24. 01:40

  1. Overview A trigger is a stored procedure in a database that automatically invokes whenever a special event in the database occurs. For example, a trigger can be invoked when a row is inserted into a specified table or when certain table columns are being updated. 2. Description 2.1 Usages automatically generate derived column values prevent invalid transactions enforce complex security author..

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• S3, Block storage, File storage, and Object storage

  DB/RDB 2020. 2. 24. 01:02

  1. Overview 2. Object Storage 2.1 What is Object Storage The term object storage, or object-based storage, derives its name because it packages data and metadata into objects. Metadata is essentially data that describes other data, or in the case of object-based storage, is information about the files that are typically stored within an object. Objects are stored in a flat structure or address s..

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• DDL, DML, DCL, and TCL

  DB/RDB 2020. 2. 23. 23:29

  1. Overview 2. Description 2.1 Data Definition Language (DDL) DDL is the short name of Data Definition Language, which deals with database schemas and descriptions, of how the data should reside in the database. CREATE – to create a database and its objects like (table, index, views, stored procedure, function, and triggers) ALTER – alters the structure of the existing database DROP – delete obj..

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• Clustered and Non clustered index

  DB/RDB 2020. 2. 23. 23:00

  1. Overview With a clustered index the rows are stored physically on the disk in the same order as the index. Therefore, there can be only one clustered index. With a non clustered index there is a second list that has pointers to the physical rows. You can have many non clustered indices, although each new index will increase the time it takes to write new records. It is generally faster to rea..

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