What is Object-Relational Mapping (ORM)?
An ORM, or object-relational mapping, is a programming technique that allows a software application to access and manipulate a database.
Category: Databases
How to automate replication of MySQL data to AWS Redshift?
We’ll use Rails framework and a Java service for this task. Ruby on Rails, or Rails, is a server-side web application framework written in Ruby under the MIT License.
Master-Slave and Multi-Master Database Replication (Quick Notes)
Database replication is usually done to achieve HA (High Availability) and load-sharing purposes. A single member of group is designated as master for a given piece of data and is the only node allowed to modify data.
Commonly Used Databases (Quick Notes)
A columnar database stores the data of an entire column in consecutive memory blocks, while a relational database stores the data of an entire row of a table in consecutive memory blocks.
Database Index
When a query is run against a column on which a secondary index is created, the database will go to the secondary index (where it is stored) and look for the address of the corresponding row in the table.
What is the relation between sharding and distributed systems?
Sharding is horizontal (row wise) database partitioning as opposed to vertical (column wise) partitioning which is Normalization.