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50 lines
1.5 KiB
Markdown
50 lines
1.5 KiB
Markdown
---
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title: "13-databases-1"
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aliases:
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tags:
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- cosc203
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- lecture
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---
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# What is a database
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- an integrated collection of data
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- implicit properties
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- represents some aspect of th real world, called miniworld
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- is a coherent collection of data with inherent meaning
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- is designed built and populated with data for a specific purpose
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## DBMS
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- a software system designed to store, manage, and facilitate access to the database
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- Oracle, SQL erver, MySQL, MonogDB
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## Application program
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- a program that provides access to the dtabase by sending queries and requests for data to the DBMS
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# This course
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- modelling and design of DBs
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- programming (SQL + appliation development)
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- DBMS implementation
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specifiically *relational databases*
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- ER modelling
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- datbase normalisation
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- SQL
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## relational vs nosql
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relation is better for structured data, nosql is better for abstract data, as it is more flexible
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# Data modelling
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first step in designing database
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- create a data model for a specific problem domain
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a model is Defn: a collection of concepts that can be used to describe the structure of a database such as data types, relationsips, and contraints that should hold for the data
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schema Defn: a collection of metadata that describes the logical view of a database
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noSQL databases are either schema-free or have relaxed schemas
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## conceptual data modelling |