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transactions active at time of crash.
- DONE Normalization
background-color:: yellow
- DONE Functional dependencies [g4g](https://www.geeksforgeeks.org/types-of-functional-dependencies-in-dbms/)
- DONE Functional dependencies [g4g](https://www.geeksforgeeks.org/types-of-functional-dependencies-in-dbms/) #flashcard
- In a relational database management, functional dependency is a concept
that specifies the relationship between two sets of attributes where one
attribute determines the value of another attribute. It is denoted as **X → Y**, where the attribute set on the left side of the arrow, **X** is called **Determinant** , and **Y** is called the **Dependent**.
@ -1075,29 +1075,29 @@
CLOCK: [2023-06-01 Thu 17:38:55]--[2023-06-01 Thu 17:38:56] => 00:00:01
:END:
- DONE kinds of NF [tutorial](https://www.geeksforgeeks.org/normal-forms-in-dbms/)
- First Normal Form (1NF): This is the most basic level of
- First Normal Form (1NF): :-> This is the most basic level of
normalization. In 1NF, each table cell should contain _only a single value, and each column should have a unique name_. The first normal form helps to eliminate duplicate data and simplify queries.
- Second Normal Form (2NF): 2NF eliminates redundant data by requiring that each _non-key attribute_ be dependent on the primary key. This means that _each column should be directly related to the primary key_, and not to other
- Second Normal Form (2NF): :-> 2NF eliminates redundant data by requiring that each _non-key attribute_ be dependent on the primary key. This means that _each column should be directly related to the primary key_, and not to other
columns.
- Third Normal Form (3NF): 3NF builds on 2NF by requiring
- Third Normal Form (3NF): :-> 3NF builds on 2NF by requiring
that _all non-key attributes are independent of each other._ This means that each column should be directly related to the primary key, and not to any other columns in the same table.
- Boyce-Codd Normal Form (BCNF): BCNF is a stricter form of 3NF that ensures that each determinant in a table is a candidate key. In other words, BCNF ensures that _each non-key attribute is dependent only on the candidate key._
- Boyce-Codd Normal Form (BCNF): :-> BCNF is a stricter form of 3NF that ensures that each determinant in a table is a candidate key. In other words, BCNF ensures that _each non-key attribute is dependent only on the candidate key._
- Fourth Normal Form (4NF): 4NF is a further refinement of BCNF that ensures that _a table does not contain any multi-valued dependencies._
- Fifth Normal Form (5NF): 5NF is the highest level of normalization and involves decomposing a table into smaller tables to _remove data redundancy and improve data integrity._
- LATER Block 4
- DONE Distributed DBMS
- DONE client server arch
- DONE client server arch #flashcard
- Computers (client) connected over wired or wireless local area network (LAN)
- The database itself and the DBMS are stored on a central device called the database server, which is also connected to the network.
- Distributed Database
- Distributed Database #flashcard
- A logically interrelated collection of shared data (and a description of this data), physically spread over a computer network.
- Distributed DBMS
- Distributed DBMS #flashcard
- Software system that permits the management of the distributed database and makes the distribution transparent to users.
- the key issues
- the key issues #flashcard
- Fragmentation
- Allocation
- Replication
- importance and different types of fragmentation
- importance and different types of fragmentation #flashcard
- Horizontal
- Vertical
- Mixed