Merge pull request #12 from hsf-training/opensearch

added and tested opensearch commands

_episodes/01-introduction.md

@@ -26,3 +26,11 @@ A database management system (DBMS) is a computer software application that inte
 and the database itself to capture and analyze data.
 
 A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases.
+
+
+
+# Relational Database Management Systems (RDMS)
+
+RDMS is a type of DBMS that organizes data into tables with rows and columns, establishing relationships between entities
+through keys. It follows the principles of the relational model and uses Structured Query Language (SQL) for data manipulation.
+Examples of RDMS include MySQL, PostgreSQL, Oracle Database, and SQL Server.

_episodes/08-intro-nosql.md

@@ -12,3 +12,22 @@ keypoints:
 - ""
 - ""
 ---
+
+# NOSQL Databases
+NSQL databases diverge from the traditional table-based structure of RDMS and are designed to handle unstructured or
+semi-structured data. They offer flexibility in data modeling and storage, supporting various data formats. Types of NoSQL database are :
+
+| NoSQL Database Type       | Description                                                  | Examples                                     |
+| ------------------------- | ------------------------------------------------------------ | -------------------------------------------- |
+| Key-Value Store           | Stores data as key-value pairs. Simple and efficient for basic storage and retrieval operations. | Redis, DynamoDB, Riak                        |
+| Document-Oriented         | Stores data in flexible JSON-like documents, allowing nested structures and complex data modeling. | MongoDB, Couchbase, CouchDB, OpenSearch, Elasticsearch                  |
+| Column-Family Store       | Organizes data into columns rather than rows, suitable for analytical queries and data warehousing. | Apache Cassandra, HBase, ScyllaDB             |
+| Graph Database            | Models data as nodes and edges, ideal for complex relationships and network analysis. | Neo4j, ArangoDB, OrientDB                      |
+| Wide-Column Store         | Similar to column-family stores but optimized for wide rows and scalable columnar data storage. | Apache HBase, Apache Kudu, Google Bigtable     |
+
+# Opensearch Databases
+Opensearch is kind of NoSQL database which is document oriented. It stores data as JSON documents.
+It is also a distributed search and analytics engine designed for scalability, real-time data processing, and full-text search capabilities.
+It is often used for log analytics, monitoring, and exploring large volumes of structured and unstructured data.
+
+In the following chapters, we will build a metadata search engine/database. We will exploit the functionality of OpenSearch to create a database where we can store files with their corresponding metadata, and look for the files that match metadata queries.