1) What is MariaDB?
It is a community based database devoloped by MySQL Devolopers. It provides same features as MySQL also, can be said that it is a replacement of MySQL.
2) Enlist some features of MariaDB.
- It supports different Programming Languages and can run on many Operating Systems.
- It provides Galera Cluster Technology.
- It has more storage engines.
- It has quicker and more transparent security release.
3) Write the default data directory for MariaDB?
The location of data directory is controlled by datadir variable. The default address is /etc/mysql/my.cnf file where MariaDBis configured to store data.
4) What is Galera Cluster in MariaDB?
Galera Cluster is a synchronous multi-master cluster for MariaDB but it is only for linux and only supports XtraDN/InnoDB.
5) Enlist some GUI/workbench for MariaDB.
- MySQL Workbench
- Webyog/SQLyog
- HeidiSQL
- dbForge Studio
6) Why does MariaDB 10.2 use InnoDB instead of XtraDB?
Keeping upto date with Mysql, MariaDB uses InnoDB/XtraDB but it has becomes a very difficult task to devolop. Devolopment was already going on with InnoDB which has taken more than half a year. Thus, to release ASAP they didn't switch to XtraDB.
7) What is an aggregate function?
Aggregate function are those functions which grouped multiple rows data on some condition to provide more significant result such as List, Set, Group etc.
8) Enlist some types of aggregate function?
- COUNT Function
- SUM Function
- MIN Function
- MAX Function
- AVG Function
9) What are the different types of Clause used in MariaDB?
- Where Clause
- Order By Clause
- Like Clause
- Distinct Clause etc.
10) What is JOIN? How many types of JOIN in MariaDB?
Join is used to retreive data from multiple tables by applieng joins such as:
- INNER JOIN
- LEFT OUTER JOIN
- RIGHT OUTER JOIN
11) What is the use of ORDER BY clause in MariaDB?
ORDER BY clause is used to sort the records in inreasing or decreasing order.
Syntax:
SELECT expressions
FROM tables
[WHERE conditions]
ORDER BY expression [ ASC | DESC ];
12) How MariaDB protects from SQL Injection?
SQL Injection problem occurs at the time of Insertion or Updation of data such as Name, Salary etc and code logic fails to analyze. To avoid SQL Injection we can provide Validation through pattern matching.
13) Enlist the types of Backups in MariaDB.
There are two types of Backups:
- Logical Backups: It provides flexibility of restoring data on another machines. Logical Backups occurs at tables and database.
- Physical Backups: This type of backups is smaller in size and vaery fast in restoring of data. It includes log and configuration files which occur at directory or file level.
14) Enlist some backup tools.
- XtraBackup
- Snapshots
- LVM
- TokuBackup
15) What is Indexs? How many types of Indexes in MariaDB?
Indexes: It is a tools which helps in faster retreival of records present in tables.
Indexes is of 4 types:
- Primary
- Unique
- Plain
- Full-Text
16) What are Heap tables?
HEAP tables are present in memory and they are used for high speed storage on temporary basis.
17) Which Is The Max Storage Capacity Of Version 5.5 Mariadb?
InnoDB/XtraDB tables can be up to 64TB (terabytes) in size. On top of this you can have multiple tables per database and multiple databases per server.
18) What are Heap tables?
HEAP tables are present in memory and they are used for high speed storage on temporary basis.
19) What is function in MariaDB?
MariaDB function is a stored program that is used to pass parameters into them and return a value.
20) What is the use of DELETE statement in MariaDB?
The MariaDB DELETE statement is used to delete one or more records from the table in the database.
21) How can you retrieve limited number of records from a table?
LIMIT clause is used with SELECT statement to select a limited number of records from a table.
22) What is a procedure or a stored procedure in database?
Procedures are sort of functions in a database. Procedures are created when you want to perform a task repetitively. MariaDB procedure is a stored program that is used to pass parameters into it. It does not return a value like a function does.
