Classification of SQL Queries

SQL (Structured Query Language) is a standard language for managing and manipulating databases. SQL is divided into different languages or subcategories based on the type of operation it performs. Here's a classification of SQL languages along with examples of queries:1. **Data Query Language (DQL)**:   - **Purpose**: Used to retrieve data from a database. ...

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Query to Connect all tables of Sakila Database of MYSQL

select g1.first_name, g1.last_name, g1.film_id, g1.actor_id, g1.title, g1.release_year,g1.language_id, g1.rating, g1.inventory_id, g1.store_id,g3.staff_id, g3.staff_firstname, g3.staff_lastname, g3.staff_email, g3.store_id,g3.address, g3.district, g3.city_id, g3.phone, g3.city, g3.country,g3.payment_id, g3.rental_id, g3.customer_id, g3.amount, g3.cust_firstname,g3.cust_lastname,...

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What is RMAN (Recovery Manager) in Oracle Database ?

RMAN stands for "Recovery Manager" and it is a key component of the Oracle database management system. RMAN is used for backup and recovery tasks, providing a centralized and efficient mechanism for managing backups, restoring data, and recovering databases in the event of failures.Here are some key features and functionalities of RMAN:1. **Backup and Recovery:** RMAN provides...

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Solved: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

Follow the given steps to solve the issue. The commands here are for CentOS 8. The solution is same for other OS as well so modify the commands accordingly.Step 1: After the installation of MYSQL is finished, enable and start mysqld as given below:sudo systemctl start mysqldsudo systemctl enable mysqldOnce, done also check the status of the mysqld to verify whether it is running...

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Steps to install oci8 on centos 8

The following steps is valid for Oracle 11g, you can modify as per your oracle version in a similar fashion.1. Install the Oracle Instant Client:    - Download the Oracle Instant Client RPM packages for your architecture from the Oracle website (https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html). You'll need  oracle-instantclient-basic , ...

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Defining and differentiating Super key and Candidate Key based on two properties

Candidate keys and super keys are concepts in relational database theory that relate to the uniqueness and irreducibility of attributes within a table's schema.1. **Super Key**:   - A super key is a set of one or more attributes (columns) that uniquely identifies each tuple (row) within a table.   - It may contain more attributes than necessary to uniquely...

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Immutable backup and how it is achieved ?

An immutable backup refers to a type of data backup that cannot be modified, altered, or deleted once it has been created. The term "immutable" implies that the data is protected from any changes, intentional or accidental, for a specified period of time or until certain conditions are met. This concept is commonly used in data protection and disaster recovery strategies to...

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Physical IP Vs Virtual IP Vs SCAN IP (with Examples)

Physical IP, Virtual IP, and SCAN IP are terms often used in the context of networking and IT infrastructure. Let's break down the differences between these concepts:1. Physical IP (Internet Protocol):A physical IP address is a unique numerical label assigned to each device (like computers, routers, servers, etc.) connected to a network. It serves as an identifier that helps in routing data packets to the correct destination. Physical IP addresses...

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Uninstall MariaDB completely along with its dependencies from the Centos

 To uninstall MariaDB on CentOS 8, you can use the `yum` package manager. Follow these steps to uninstall MariaDB:1. **Stop the MariaDB service**:   Before uninstalling, it's better to stop the MariaDB service to avoid any issues. Open a terminal and run the following command:   sudo systemctl stop mariadb2. **Remove the MariaDB packages**:   Once the service is stopped, you can proceed to remove the MariaDB packages...

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Install MariaDB on Centos

 To install MariaDB on CentOS 8, follow these steps:1. Update the system packages:   Before installing any software, it's a good idea to update your system to ensure you have the latest packages. Open a terminal or SSH into your CentOS 8 server and run the following commands:   sudo dnf clean all   sudo dnf update2. Install MariaDB server:CentOS 8 uses the DNF package manager, so you can easily install MariaDB by...

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Solved: MariaDB failed to start with error message "job for mairadb.service failed because the control process exited with error code"

Here are some steps you can follow to resolve the issue:1. **Check for Running Processes**: As the logs indicate, another process is already using port 3306. You can verify this by running the following command:   sudo netstat -tulnp | grep 3306 The command will show you the process ID (PID) of the process using port 3306. Make a note of the PID.for example,[root@Pinrecovery ~]# sudo netstat -tulnp | grep 3306tcp6     ...

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Solution for "error 1045: access denied for user 'root'@'localhost' (using password: no)"

The error message "1045: Access denied for user 'root'@'localhost' (using password: no)" indicates that you are trying to connect to the MariaDB database server as the 'root' user without providing a password, but the server is expecting one.Here are some steps to troubleshoot and resolve the issue:1. Check your password:   Ensure that you are using the correct password for the 'root' user. By default, MariaDB sets an empty password for...

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Will "mysqli" extension work for MariaDB database?

Yes, `mysqli` can work with MariaDB in PHP. The `mysqli` extension stands for "MySQL Improved" and is designed to work with both MySQL and MariaDB databases. MariaDB is a fork of MySQL, so they share a lot of similarities and are largely compatible with each other.When you use the `mysqli` extension in PHP, you can connect to both MySQL and MariaDB databases using the same functions and methods. This is because the `mysqli` extension provides an...

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Install oci8 on centos 8

 Install oci8 on centos 8 Now that you have the necessary tools and libraries installed, you can proceed with the next steps to install the OCI8 extension for PHP on CentOS 8: 1. Install the Oracle Instant Client:   - Download the Oracle Instant Client RPM packages for your architecture from the Oracle website (https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html). You'll need  oracle-instantclient-basic...

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What is Archive logs in Oracle database?

An archive log is a term commonly used in the context of database management systems, particularly with relation to Oracle Database.In a database system, the archive log refers to a copy of a redo log file that has been filled with data and then archived (backed up) to a storage location, such as a separate disk or tape. The redo log files store a record of changes made to...

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Differences between Datafile and Tablespace

  Datafile Tablespace Definition Physical file used by the DBMS to store data Logical storage container within a database Purpose Stores actual data, indexes, and other database objects Provides a logical organization and management structure for storing and accessing data ...

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