================ Database Journal

.. image:: images/types_of_dbs.png :align: center :width: 150pt

This repository is a collection of all-things database. It includes some fundamental concepts of databases, code samples, interview questions and more.

Index:

• Database commands <https://github.com/hardikvasa/database-journal#database-commands>__
• Code Samples <https://github.com/hardikvasa/database-journal#code-samples>__
• Selecting the right database <https://github.com/hardikvasa/database-journal#dbms-comparison-chart>__
• Interview Questions <interview-questions/README.rst>__

Database commands

+---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+ | DBMS | Model | Description | Runtime | Link | +===============+============+=======================================+=========+=====================================================================================================+ | MySQL | Relational | Mysql basic commands | Shell | link <database-commands/mysql_commands.rst>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+ | MongoDB | Document | MongoDB basic commands | Shell | link <database-commands/mongodb.rst>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+

Code Samples

This section contains sample codes for database operations. For python, there are several options like mysql-connector, pymysql, MySQLdb, SqlAlchemy, etc.

+---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | DBMS | Model | Description | Runtime | Sample Code | Docs | +===============+============+=======================================+=========+=====================================================================================================+=========================================================================================================+ | MySQL | Relational | Python mysql connector code sample | Python | link <code-samples/mysql_connector_sample.py>__ | docs <https://dev.mysql.com/doc/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | MySQL | Relational | PyMySQL code sample | Python | link <code-samples/pymysql_sample.py>__ | docs <https://dev.mysql.com/doc/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | PostgreSQL | Relational | PostgreSQL using psycopg2 code sample | Python | link <code-samples/postgresql.py>__ | docs <https://www.postgresql.org/docs/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | MongoDB | Document | MongoDB NoSQL database code sample | Python | link <code-samples/mongo.py>__ | docs <https://docs.mongodb.com/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | SQS | Queue | AWS Simple Queue Service operations | Python | link <code-samples/sqs.py>__ | docs <https://docs.aws.amazon.com/sqs/index.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | ActiveMQ | Queue | MQ Producer and MQ Consumer | Python | link <code-samples/mq_producer.py>, link <code-samples/mq_consumer.py> | docs <https://activemq.apache.org/getting-started.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | ActiveMQ | Queue | MQ Producer and MQ Consumer | Java | link <code-samples/MQProducer.java>, link <code-samples/MQConsumer.java> | docs <https://activemq.apache.org/getting-started.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | OracleDB | Relational | OracleDB sample code | Python | link <code-samples/oracledb.py>_ | docs <https://cx-oracle.readthedocs.io/en/latest/index.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | Kinesis | Stream | AWS Kinesis stream sample code. | Python | link <code-samples/kinesis_producer.py>, link <code-samples/kinesis_consumer.py> | docs <https://docs.aws.amazon.com/streams/latest/dev/introduction.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | Redis | In-memory | Redis code sample in python. | Python | link <code-samples/redis_python.py>_ | docs <https://redis.io/documentation>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | Neo4j | Graph | Graph database using neo4j-driver | Python | link <code-samples/neo4j_sample.py>_ | docs <https://neo4j.com/docs/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | DynamoDB | Document | DynamoDB basic operations | Python | link <code-samples/dynamodb.py>_ | docs <https://docs.aws.amazon.com/dynamodb/index.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | ElasticSearch | Search | ElasticSearch basic operations | Python | link <code-samples/elasticsearch_sample.py>_ | docs <https://www.elastic.co/guide/index.html>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | AWS Neptune | Graph | Connecting to AWS Neptune with Gremlin| Python | link <code-samples/aws_neptune.py>_ | docs <http://tinkerpop.apache.org/docs/current/reference/>__ | +---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | Cassandra | Wide-column| Cassandra basic operations | Python | link <code-samples/cassandra_sample.py>_ | docs <http://cassandra.apache.org/doc/latest/>__ |
+---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+ | Amazon Aurora | MySQL | Basic Operations for Aurora DB | Python | link <code-samples/aurora.py>_ | docs <https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/CHAP_AuroraOverview.html>__ |
+---------------+------------+---------------------------------------+---------+-----------------------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------+

DBMS comparison chart

This section some characteristics and comparison points between different database technologies.

+-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Property | Relational DB | NoSQL DB | Document DB | In-memory DB | Graph DB | Search DB | Time-series DB | Ledger DB | Queues | Streams | +=================+====================+=====================+=====================+==================+===============+=================+====================+================+===================+===========================+ | Type | Relational | Non-Relational | Non-Relational | Non-Relational | Relational | Non-Relational | Relational | Non-Relational | Non-Relational | Non-Relational | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Data | Structured | Un-structured | Un-structured | Un-structured | Un-structured | Semi-structured | Structured | Chain | Un-structured | Un-structured | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Data format | Records, tuples | JSON | JSON | JSON | N/A | JSON | JSON | JSON | Objects | Objects | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Scalability | Vertical | Horizontal | Horizontal | Horizontal | Horizontal | Horizontal | Horizontal | Horizontal | Horizontal | Horizontal | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Record type | Flat | Hierarchical | Hierarchical | Hierarchical | Hierarchical | Hierarchical | Flat, Hierarchical | Hierarchical | Objects | Objects | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Applications | CRM, Finance | Shopping cart | Content Management | Leaderboards | Social media | Product catalog | IoT applications | Cryptocurrency | Queuing tasks | Weather data | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Complex queries | Yes | No | No | No | No | No | No | No | N/A | N/A | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Property | ACID | CAP theorem | CAP theorem | CAP theorem | CAP theorem | CAP theorem | ACID | N/A | N/A | N/A | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+ | Engine(s) | MySQL, PostgresSQL | Cassandra, DynamoDB | MongoDB, DocumentDB | Redis, Memcached | Neo4j | Elasticsearch | InfluxDB | AWS QLDB | ActiveMQ, AWS SQS | Apache Kafka, AWS Kinesis | +-----------------+--------------------+---------------------+---------------------+------------------+---------------+-----------------+--------------------+----------------+-------------------+---------------------------+

Contributing

Anyone is welcomed to contribute to this repository. If you would like to make a change, open a pull request. For issues and discussion visit the Issue Tracker <https://github.com/hardikvasa/database-journal/issues>. Additional articles and workshops can be found on website <https://cloudbru.com/>.

Disclaimer

The contents of this repository is merely for educational purpose. The content may not be accurate or up-to-date.