Optimisation Flashcards
1
Q
What is a Database Index?
A
A data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space.
2
Q
What are Indexes used for?
A
Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed.
3
Q
What is an ordered Binary Tree?
A
- An ordered binary tree consists of nodes
2. Each node has a value and up to two children
4
Q
What is Cardinality of an index?
A
the number of distinct values
5
Q
Why is an Index of high cardinality of more value?
A
Discriminates better.
