Every business, especially a constantly business, has different data storage demands, and often they can't be fulfilled by a single Data Source. Although there are several Data Sources that can be considered all-around players (for example, PostgreSQL), there is no silver bullet that targets all needs, and it's not a rare case to see more than one Data Source in use.

The following is a real world example.

A company uses MySQL for financial transaction management, ElasticSearch is used to provide users with quick text search on their stored data, and Google Analytics is used to track their website metrics.

As of the current Redash version (version 5.0.0 at the time of writing this book), the following Data Sources are supported:

If you found that your desired Data Source is not in the list, it's about time to check the requierements_all_ds.txt and requirements_oracle_ds.txt files, and install the missing dependencies.

More on that in Chapter 8, Customizing Redash.

Cassandra, Oracle, SnowFlake, ScyllaDB, appmetrika, metrika

A word on each Data Source:

• Amazon Athena: An AWS serverless service that allows you to execute SQL like queries on data that resides on S3 (https://aws.amazon.com/athena/).
  Query language: SQL
• Axibase Time Series Database: A non-relational database that is optimized for temporal data collection and analysis (metrics) (https://axibase.com/products/axibase-time-series-database/).
  Query language: SQL
• BigQuery: Google's serverless, highly scalable, enterprise data warehouse (https://cloud.google.com/bigquery/).
  Query language: SQL
• Cassandra: Open source, distributed, wide column store initially developed at Facebook. Masterless design, provides high availability with no single point of failure (http://cassandra.apache.org/).
  Query language: CQL (SQL like)
• ClickHouse: Yandex's open source column-oriented DBMS, which is fault-tolerant and linearly scalable (https://clickhouse.yandex/).
  Query language: SQL
• CockroachDB: A distributed, horizontally scalable database based on the transactional and strongly consistent KV store (https://www.cockroachlabs.com/).
  Query language: SQL
• DyanamoDB (with DQL): An AWS serverless non-relational database that supports KeyValue and document store models (DQL is a special wrapper that allows executing SQL-like queries; https://aws.amazon.com/dynamodb/).
  Query language: SQL
• ElasticSearch: A distributed, RESTful search and analytics engine built on top of Lucene (https://www.elastic.co/products/elasticsearch).
  Query language: JSON
• Google Analytics: Google's web analytics service that tracks and reports website traffic (https://developers.google.com/analytics/devguides/reporting/core/v4/).
  Query language: JSON
  
• GoogleSpreadSheet: An online spreadsheet app that lets you create and format spreadsheets.
  (https://www.google.com/sheets/about/)
  Query language: Text
• Graphite: An open source tool that monitors and graphs numeric time series data.
  (https://graphiteapp.org/)
  Query language: Text
  
• Hive: Apache's data warehouse software project on top of Apache Hadoop.
  (https://hive.apache.org/)
  Query language: SQL
• Impala: Apache's, open source, distributed SQL query engine for Apache Hadoop.
  (https://impala.apache.org/)
  Query language: SQL
• InfluxDB: An open source time series DB platform for metrics and events.
  (https://www.influxdata.com/)
  Query language: SQL
• JIRA (JQL): A connector that allows you to run JQL (Jira Query Language) queries to fetch data from Atlassian's Jira (issue and project tracking software).
  (https://confluence.atlassian.com/jiracore/blog/2015/07/search-jira-like-a-boss-with-jql)
  Query language: Text (somewhat similar to SQL, but has specific syntax)
• Kibana: Outside of the Redash context, Kibana is a visualization tool for ElasticSearch. In the context of Redash, Kibana is just a different querying flavor of ElasticSearch.
  (https://www.elastic.co/guide/en/kibana/current/lucene-query.html)
  Query language: Text (Lucene querying syntax)
• Mapd: An open source relational, columnar SQL engine that was developed to harness GPU computing for real-time analytics (https://www.mapd.com/).
  Query language: SQL
  
• MemSQL: A distributed, in-memory, SQL database management system, compatible with MySQL (https://www.memsql.com/).
  Query language: SQL
• Microsoft SQL Server: Microsoft's RDBMS (https://www.microsoft.com/en-us/sql-server/sql-server-2017).
  Query language: SQL
• MongoDB: An open source document-oriented NoSQL datastore (https://www.mongodb.com/).
  Query language: JSON
• MySQL/MariaDB: The most popular open source DBMS (https://mariadb.org/), (https://www.mysql.com/).
  Query language: SQL
• MySQL (Amazon RDS): The same as MySQL, but it has different connection parameters since it resides on AWS Relational Database Service (RDS) (https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_MySQL.html).
  Query language: SQL
• Oracle Database: Multi-model DBMS made by Oracle, mostly used for running online transaction processing (OLTP), data warehousing (DW), and mixed (OLTP and DW) database workloads (https://www.oracle.com/database/index.html).
  Query Language: SQL
• PostgreSQL: An open source ORDBMS (Object-Relational Database Management System), considered the most advanced open source database (https://www.postgresql.org/).
  Query language: SQL
• Presto: An open source distributed SQL query engine for running interactive analytic queries against Data Sources of all sizes, such as (but not limited to) Hive/Cassandra/Redis and so on (https://prestodb.io/).
  Query language: SQL
• Prometheus: An open source monitoring system with a dimensional data model, flexible query language, efficient time series database, and modern alerting approach (https://prometheus.io/).
  Query language: Text (specific prometheus syntax)
• Qubole: A self-service platform for big data analytics built on Amazon, Microsoft, Google, and Oracle clouds (https://www.qubole.com/).
  Query language: SQL
• Query Results (Beta): Redash's option to treat any query result set as a new Data Source.
  Query language: SQL
• Redshift: An AWS severless massively parallel columnar storage analytical data warehouse.
  (https://aws.amazon.com/redshift/)
  Query language: SQL 
• Salesforce: A connector that allows you to run SQL queries on Salesforce data using the Salesforce Object Query language (SOQL) (https://developer.salesforce.com/docs/atlas.en-us.soql_sosl.meta/soql_sosl/sforce_api_calls_soql.htm).
  Query language: SQL 
• ScyllaDB: Open Source distributed NoSQL data store, designed to be compatible with Apache Cassandra and provide higher throughput and lower latencies.  (https://www.scylladb.com/)
  Query language: CQL
• SnowFlake: Serverless Analytic Data Warehouse (https://www.snowflake.com/about/)
  Query language: SQL
• Sqlite: A self-contained, highly reliable embedded SQL engine (https://www.sqlite.org/).
  Query language: SQL
• TreasureData: Arm's cloud analytics and management platform for data (emphasis on data for the Internet of Things (IoT); https://www.treasuredata.com/).
  Query language: SQL
• Url: Redash's option to fetch data from any web-based source (a special format for this is needed, which is described in this chapter).
  Query language: None
• Vertica: A highly available, massively scalable, columnar storage analytical database platform, designed to provide fast query performance even on large volumes of data (https://www.vertica.com/).
  Query language: SQL
• Yandex AppMetrika: AppMetrica is a marketing platform for app install attribution, app analytics, and push campaigns (https://appmetrica.yandex.com/).
  Query language: SQL

• Yandex Metrika: All-Round Web Analytics including, but not limited to, traffic trends, mouse movements, ad campaigns, user analytics, and so on (https://metrica.yandex.com/) get a comprehensive understanding of your online audience and drive business growth.
  Query language: SQL