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Articles on Trending Technologies
Technical articles with clear explanations and examples
Difference Between RDBMS and Hadoop
RDBMS stores structured data in tables with ACID compliance using SQL. Hadoop is an open-source framework for distributed storage and processing of large-scale structured and unstructured data using HDFS and MapReduce. What is RDBMS? RDBMS (Relational Database Management System) stores data in tables with rows and columns, following ACID properties (Atomicity, Consistency, Isolation, Durability). It is designed for fast storage and retrieval of structured data using SQL. Examples: Oracle, MySQL, PostgreSQL. What is Hadoop? Hadoop is an open-source framework for running distributed applications and storing large-scale data. It handles structured, semi-structured, and unstructured data with high ...
Read MoreHow To Configure PostgreSQL 12 Streaming Replication in CentOS 8?
PostgreSQL Streaming Replication continuously streams Write-Ahead Log (WAL) data from a primary (master) node to standby (slave) nodes, creating near-real-time database copies for high availability and fault tolerance. Master Read/Write WAL Slave 1 Slave 2 Read-only Read-only Master Node Configuration 1. Enable WAL Archiving Edit ...
Read MoreHow to Download and Install PostgreSQL on Windows?
PostgreSQL is a powerful, open-source relational database system used for enterprise applications. This guide covers downloading, installing, configuring, and testing PostgreSQL on Windows. Downloading PostgreSQL Go to postgresql.org/download/windows Click Download the installer (EnterpriseDB graphical installer) Select the latest version for your OS (64-bit recommended) Download will begin automatically Installing PostgreSQL Run the downloaded installer and follow these steps − Step 1: Welcome screen → Click Next Step 2: Select components (keep all selected: PostgreSQL Server, pgAdmin, Command Line Tools, Stack Builder) Step 3: Choose installation directory (default recommended) Step 4: Choose data ...
Read MoreHow to Deploy PostgreSQL on Kubernetes?
PostgreSQL is an open-source RDBMS known for handling complex datasets. Kubernetes automates deployment, scaling, and management of containerized applications. Deploying PostgreSQL on Kubernetes provides automated scaling, rolling updates, and improved reliability through replicas and failover. Deployment Steps Cluster Image Manifest Deploy ...
Read MoreOverview of Dynamic Partition in Hive
Apache Hive is a data warehousing system built on Hadoop for analytics and MapReduce jobs. Partitioning divides large datasets into smaller parts for faster queries. Dynamic partitioning automatically determines partition values from the data being inserted, unlike static partitioning where values are manually specified. Static vs Dynamic Partitioning Feature Static Partitioning Dynamic Partitioning Partition values Manually specified per insert Automatically derived from data Best for Few known partitions Many or unknown partitions WHERE clause Required Not required Flexibility Low High Enabling Dynamic Partitioning ...
Read MoreOracle Label-Based Security
Oracle Label-Based Security (OLS) provides fine-grained, row-level access control based on security labels. Each row of data is assigned a sensitivity label (e.g., Confidential, Secret, Top Secret), and each user is assigned a clearance level. Users can only access data where their clearance meets or exceeds the data's sensitivity. How OLS Works User Clearance: SECRET ...
Read MoreOperations on table in Cassandra
Cassandra uses CQL (Cassandra Query Language) to perform operations on tables. CQL is similar to SQL but designed for Cassandra's distributed, NoSQL architecture. The main table operations are CREATE, INSERT, UPDATE, DELETE, SELECT, ALTER, and DROP. CREATE TABLE CREATE TABLE sample_table ( id INT PRIMARY KEY, name TEXT, age INT, email TEXT ); INSERT Data INSERT INTO sample_table (id, name, age, email) VALUES (1, 'John Doe', 35, 'john@example.com'); INSERT INTO sample_table (id, name, age, email) VALUES ...
Read MoreOperations on Files
When working with files in a DBMS, two fundamental types of operations are performed: retrieval (finding and reading records) and update (inserting, deleting, or modifying records). Both use selection conditions to identify target records. Selection Conditions A selection condition specifies criteria that records must meet. Conditions can be − Simple − Uses one field (e.g., Ssn = '123-45-6789') Complex − Combines multiple fields with comparison operators (e.g., Department = 'Sales' AND Salary ≥ 30000) File Operations The typical sequence of file operations − 1. Open file 2. Find first record matching ...
Read MoreOn Line Transaction Processing (OLTP) System in DBMS
OLTP (On-Line Transaction Processing) systems manage real-time transaction tasks − entering, storing, and retrieving data for daily operations like purchasing, payroll, and accounting. Examples include supermarket POS systems, order entry, retail sales, and financial transaction systems. Users POS, Web, App OLTP System INSERT, UPDATE DELETE, SELECT ...
Read MoreOLAP Operations in DBMS
OLAP (Online Analytical Processing) enables users to perform multidimensional analysis on data organized into cubes (hypercubes). Each cell in a cube corresponds to a specific combination of dimension values (e.g., Location → Time → Product). OLAP uses pre-aggregation and indexing for fast querying. Types of OLAP Servers Type Storage Trade-off ROLAP Relational database (SQL queries) Handles large data, slower queries MOLAP Multidimensional arrays Fast queries, limited data size HOLAP Hybrid (ROLAP + MOLAP) Scalability + speed balance OLAP Operations ...
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