From 928e6c452fe84f0d3691d2f89bbc57062746e25c Mon Sep 17 00:00:00 2001 From: ION606 Date: Wed, 29 Jan 2025 23:13:48 +0000 Subject: [PATCH] Update Notes.md --- Database Systems/Notes.md | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/Database Systems/Notes.md b/Database Systems/Notes.md index 86c204d..05c2c9a 100644 --- a/Database Systems/Notes.md +++ b/Database Systems/Notes.md @@ -14,7 +14,7 @@ my server crashed towards the end of the year, so most of the images are gone. I - Database Management Systems (DBMS) - a software tool for storing/managing large amounts of data - Database Server - a specific installation of a DBMS -- Database - a collection of data (often in a DBMS) organized for a specific application (also see [Database Section](https://cloud.ion606.com/apps/files/files#h-databases)) +- Database - a collection of data (often in a DBMS) organized for a specific application (also see [Database Section](https://github.com/ION606/learn/blob/main/Database%20Systems/Notes.md#databases)) - Database Application - a software product that uses DBMSs to store one or more databases for a specific purpose - Database Schema - what types of data are valid to store @@ -31,8 +31,8 @@ my server crashed towards the end of the year, so most of the images are gone. I - rules about the data (Database Schema) - design so that you hopefully never have to make changes, cause making changes later on is difficult - Transaction - a program that changes data or a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) -- ACID - see [ACID Section](https://cloud.ion606.com/apps/files/files/34361?dir=/School/Senior%20Year/Datbase%20Systems&openfile=true#h-a-c-i-d) -- Relational Data Model - see [Relational Data Model](https://cloud.ion606.com/apps/files/files/34361?dir=/School/Senior%20Year/Datbase%20Systems&openfile=true#h-relational-data-model) section +- ACID - see [ACID Section](https://github.com/ION606/learn/blob/main/Database%20Systems/Notes.md#boyce-codd-normal-form-bcnf) +- Relational Data Model - see [Relational Data Model](https://github.com/ION606/learn/blob/main/Database%20Systems/Notes.md#relational-data-model) section - Key - some attribute that determines other keys, you can have multiple keys - minimal key - the minimum set of attributes needed to get the correct info - super key - any superset containing the minimal key (any superset of the minimal key) @@ -46,8 +46,8 @@ my server crashed towards the end of the year, so most of the images are gone. I - Database Schema + Database Instance + Application Logic - Relational Data Model - set of relations -- BCNF - see [BCNF](https://cloud.ion606.com/apps/files/files/34361?dir=/School/Senior%20Year/Datbase%20Systems&openfile=true#h-boyce-codd-normal-form-bcnf) section -- Entity-Relationship Models - See [ER](https://cloud.ion606.com/apps/files/files/34361?dir=/School/Senior%20Year/Datbase%20Systems&openfile=true#h-entity-relationship-models-er) section +- BCNF - see [BCNF](https://github.com/ION606/learn/blob/main/Database%20Systems/Notes.md#boyce-codd-normal-form-bcnf) section +- Entity-Relationship Models - See [ER](https://github.com/ION606/learn/blob/main/Database%20Systems/Notes.md#entity-relationship-er-models) section ### What Makes a DBMS @@ -4084,8 +4084,7 @@ EXAMPLE: ## Query Processing - SQL queries are converted to bag relational algebra queries to be implemented Overall picture of the DBMS system components -![[Pasted image 20241201144514.png]] -MOVE TO NEXTCLOUD???? + #### Disk Access Process (Overly Simplified) - to process any data, it must first be brought to memory