Introducing a simple database Database tutorial (1)
Database
1 Definition
Database can be simply explained as: an efficient medium for storing and processing data (mainly divided into two types: disk and memory).
2 Classification
According to different database storage media, it can be divided into two categories, namely: relational database (SQL) and non-relational database (NoSQL, Not Only SQL).
3 Example
Relational database:
Large-scale: Oracle, DB2, etc.;
Medium-sized: SQL Server, MySQL, etc.;
Small: Access etc.
Non-relational databases:
Memcached, MongoDB and Redis, etc.
4 Difference
Relational database:
Safe, it saves data to the disk, and it is basically impossible to lose data;
It is a waste of space because it stores data in the form of a two-dimensional table.
Non-relational database:
The efficiency of storing data is relatively high;
is not particularly safe, and a sudden power outage will cause data loss.
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