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Articles on Trending Technologies
Technical articles with clear explanations and examples
How 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 ...
Read MoreObject-Relational Features_ Object Database Extensions to SQL
The object-relational model combines relational databases with object database features. SQL (starting from SQL:1999 and refined in SQL:2008) incorporates object extensions including user-defined types, object identity, encapsulation, and inheritance. Key Object Features in SQL Feature Description Type Constructors ROW type (struct), ARRAY, SET, LIST, BAG for complex objects Object Identity REF types provide unique object identifiers (OIDs) Encapsulation Methods defined within UDTs (User-Defined Types) Inheritance UNDER keyword for type and table inheritance User-Defined Types (UDTs) UDTs allow creating complex-structured objects with custom attributes and ...
Read MoreObject Database Conceptual Design
An object database stores data as objects (containing both data and methods), working directly with object-oriented programming languages like Java and Python. Object-oriented modeling supports inheritance, encapsulation, and polymorphism, making it more flexible than the traditional relational model for complex relationships. ODB vs RDB Conceptual Design Feature Object Database (ODB) Relational Database (RDB) Relationships OID references (single or collections) Matching attribute values (foreign keys) Inheritance Built-in (extends, derives) No built-in construct Operations Part of class definition, specified early Can be delayed to implementation Multivalued Attributes Supported (set, bag, ...
Read MoreNumber of Possible Super Keys in DBMS
A super key is a set of one or more attributes that uniquely identifies each record in a table. All primary/candidate keys are super keys, but not all super keys are candidate keys (candidate keys are minimal super keys with no redundant attributes). Key Formulas Scenario (n = total attributes) Formula One candidate key with k attributes 2(n−k) Maximum super keys (at least 1 attribute) 2n − 1 Two candidate keys (Inclusion-Exclusion) SK(A1) + SK(A2) − SK(A1 ∪ A2) Three candidate keys SK(A1) + SK(A2) + SK(A3) − ...
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