Chapter 6

Data

This chapter provides an introduction to key aspects of data management.

Data At Rest

This section covers data at rest, storage technologies, and architectures, including data lakes and lake house architectures.

Data In Motion

This section covers data in motion, pipeline technologies,and architectures, including stream processing and ETL.

Data Formats

This section covers common data formats used in modern analytics, including CSV, JSON, and Parquet.

Data Stores

This section covers popular data storage systems, including SQL and NoSQL databases, graph databases, and key-value stores. Examples include PostgreSQL, MongoDB, Neo4j, and Redis.

Message Queues

This section covers popular message queue systems used to route information from decoupled applications and services. It introduces popular options including RabbitMQ and Apache Kafka.

Data Processing Engines

This section covers popular data processing engines, including Apache Spark, Apache Flink, and Apache Beam.

Subsections of Data

Data at Rest

Data at rest refers to data that is stored and not actively being processed or transmitted. This includes data stored in databases, data warehouses, data lakes, and other storage systems.

Data Lakes

A data lake is a centralized repository that allows organizations to store and manage large amounts of structured and unstructured data at scale. Data lakes provide a cost-effective and flexible way to store data from various sources and formats, and can support a wide range of data processing and analytics tools.

Delta Lake

Delta Lake is an open-source data storage and management system that is designed for large-scale data lakes. It was developed by Databricks, and it provides a number of advanced features, including ACID transactions, version control, and schema enforcement, that make it easier to manage large and complex data sets.

Delta Lake is built on top of Apache Spark, and it provides a unified platform for managing structured, semi-structured, and unstructured data in a single system. With Delta Lake, data analysts and engineers can build and manage data lakes and ensure their data is accurate, consistent, and reliable.

Lake House Architecture

Lake house architecture is an emerging approach to data storage and management that combines the benefits of data lakes and traditional data warehouses. It provides a scalable and flexible platform for storing and processing data, while also providing strong data governance and security controls.

SQL Databases

SQL databases are a popular type of relational database that use Structured Query Language (SQL) to manage and retrieve data. SQL databases are widely used for a range of applications, including transaction processing, data warehousing, and analytics.

Some popular SQL databases include:

  • MySQL
  • PostgreSQL
  • Microsoft SQL Server
  • Oracle Database

NoSQL Databases

NoSQL databases are non-relational databases that can handle large volumes of unstructured and semi-structured data. They are often used for applications that require high scalability and performance, such as real-time data processing and analytics.

Some popular NoSQL databases include:

  • MongoDB
  • Cassandra
  • Couchbase
  • Amazon DynamoDB

Graph Databases

Graph databases are specialized databases designed to store and manage graph data structures. They are often used for applications that involve complex relationships and dependencies, such as social networks and recommendation systems.

Some popular graph databases include:

  • ArangoDB
  • Neo4j
  • OrientDB

Data Warehouses

Data warehouses are specialized databases designed for storing and analyzing large volumes of structured data. They are often used for business intelligence and analytics applications, and typically support complex queries and reporting.

Some popular data warehouses include:

  • Snowflake
  • Amazon Redshift
  • Google BigQuery
  • Microsoft Azure SQL Data Warehouse

Snowflake (Commerical)

Snowflake is a cloud-based data warehousing platform that allows organizations to store, manage, and analyze large volumes of structured and semi-structured data in real-time. Snowflake’s architecture is designed to separate storage and compute, allowing users to scale each independently and pay only for what they use. This makes it a popular choice for data-intensive workloads that require fast and flexible access to data. Additionally, Snowflake provides a range of tools and features for data management, such as data sharing, secure data exchange, and automated data governance, which can help organizations simplify their data operations and reduce costs. Snowflake is a powerful and flexible data warehousing platform gaining popularity among organizations of all sizes and industries.

Open-Source Options

There are several open source alternatives to Snowflake that offer similar functionality, including:

Apache Druid

A high-performance, column-oriented, distributed data store designed for real-time analytics. Druid is optimized for OLAP queries on large-scale datasets and offers sub-second query response times.

Apache Pinot

Another high-performance, distributed data store designed for OLAP queries. Pinot is optimized for handling large-scale datasets and supports real-time ingestion and querying of data.

ClickHouse

A high-performance column-oriented database management system designed for OLAP queries. ClickHouse is optimized for handling large-scale datasets and provides sub-second query response times. It also supports real-time data ingestion and offers a variety of storage formats and compression algorithms.

Presto

A distributed SQL query engine designed for querying large-scale datasets stored in a variety of data sources, including Hadoop, HDFS, Amazon S3, and more. Presto is optimized for ad hoc querying and provides fast query response times.

Apache Arrow

A columnar in-memory data structure and computation framework designed for high-performance data processing. Arrow is optimized for efficient data sharing and serialization across different programming languages and systems.

See Also

Data in Motion

Data in motion refers to data that is actively being transmitted or processed in a system, often through pipelines that move data between different stages of processing.

Data Pipelines

Data pipelines are a series of connected processing elements that move data between different stages of processing. A typical data pipeline involves several stages of processing, such as ingestion, transformation, enrichment, and analysis, with data moving from one stage to the next as it is processed.

Pipelines can be used to move data between different applications or systems, or to transform and enrich data as it moves through a system. They are often used in real-time or near-real-time applications, such as stream processing or real-time analytics.

Stream Processing

Stream processing is a type of data processing that involves processing data as it is generated or ingested, rather than processing it after it has been stored. Stream processing can be used to analyze or filter data in real-time, and is often used in applications such as fraud detection, sensor data processing, and real-time analytics.

Popular stream processing platforms include Apache Kafka, Apache Flink, and Apache Storm.

Batch Processing

Batch processing involves processing large volumes of data in a batch or offline mode, often in a scheduled or periodic manner. Batch processing can be used to perform complex data transformations, such as ETL (extract, transform, load) operations, and is often used in applications such as data warehousing and business intelligence.

Popular batch processing platforms include Apache Spark and Apache Hadoop.

Data Integration

Data integration involves combining data from multiple sources and making it available for analysis or processing. This can involve moving data between different systems or applications, or transforming and merging data to create a unified view of the data.

Popular data integration platforms include Apache NiFi, Talend, and Microsoft Azure Data Factory.

Data Governance

Data governance involves managing the availability, usability, integrity, and security of data used in an organization. Data governance can be applied to data in motion as well as data at rest, and involves establishing policies and procedures for managing data throughout its lifecycle.

Popular data governance platforms include Collibra and Informatica.

Summary

Data in motion is a critical component of modern data architectures, and involves moving and processing data in real-time or near-real-time. Data pipelines, stream processing, batch processing, data integration, and data governance are all important aspects of managing and analyzing data in motion.

See Also

Data Formats

Modern analytics involves working with a variety of data formats that can be structured or unstructured, batch or streaming, and of varying sizes. Understanding these different data formats is essential for data analysts to effectively work with and derive insights from data.

CSV

Comma-separated values (CSV) is a widely-used file format for storing and exchanging tabular data. It consists of rows of data, where each row represents a single record, and columns of data, where each column represents a specific attribute of the record. CSV files are easy to create and read, and can be easily imported and exported by most software applications.

JSON

JavaScript Object Notation (JSON) is a lightweight and flexible file format for storing and exchanging data. It consists of key-value pairs, where each key represents a specific attribute of the data, and each value represents the value of that attribute. JSON files are easy to read and write, and can be easily parsed by most programming languages.

YAML

YAML is a human-readable data serialization language that is commonly used for configuration files, data exchange, and data storage.

The name “YAML” stands for “YAML Ain’t Markup Language,” highlighting its focus on being a data-oriented language rather than a markup language like XML or HTML.

YAML syntax is designed to be simple and easy to understand, using indentation and a minimal set of punctuation marks.

It supports a wide range of data types, including strings, integers, lists, and dictionaries. YAML is often used in software development to define configuration settings for applications and services, and is also used in data analysis and machine learning workflows to define and exchange data. YAML’s simplicity, readability and support for hierarchical data structures and lists, make it a popular choice for configuration files.

Python pyproject.toml

In Python, the pyproject.toml file is used to specify project metadata, dependencies, and build configurations in a standard format that can be easily read and understood by humans.

The pyproject.toml file is often used with pip and Poetry package managers to manage Python projects and their dependencies.

The pyproject.toml file was introduced in PEP 518
as a way to specify build system requirements for Python projects. The file is used with build tools like flit, poetry, and setuptools to manage build configuration, dependencies, and metadata.

It is becoming increasingly popular in the Python ecosystem as it provides a unified way to manage and specify various aspects of a Python project’s build process. The pyproject.toml file typically includes information such as:

  • project name,
  • version,
  • author,
  • license,
  • dependencies, and
  • build tool configuration.

By using this file, developers ensure their projects are built in a consistent and reproducible manner across different systems and environments.

Julia Project.toml

In Julia, the Project.toml file serves a similar purpose, providing a standard format for specifying project metadata and dependencies. The Manifest.toml file is used to keep track of the exact versions of packages that have been installed in a Julia environment.

Parquet

Apache Parquet is a columnar storage format for Hadoop that is optimized for performance and efficiency. It stores data in a compressed and binary format, and is designed to work with big data processing frameworks like Apache Spark and Apache Hadoop. Parquet files can be easily read and written by most data processing tools, and provide fast access to large amounts of data.

Avro

Apache Avro is a binary data serialization system that is designed for high-performance and efficient data processing. It provides a compact binary format for data storage and exchange, and includes features for schema evolution and data compression. Avro files can be easily read and written by most programming languages, and are widely used in big data processing and messaging systems.

Other Data Formats

There are many other data formats used in modern analytics, including XML and Apache Arrow.

The choice of data format depends on the specific needs and requirements of the data analysis project, including factors such as data size, performance, and compatibility with existing data processing tools and systems.

Data Stores

Data stores are used to store, manage and retrieve data.

There are many types of data stores available, each with their own strengths and weaknesses. Some of the most popular data stores include the following.

Relational Databases

Relational databases store data in tables with columns and rows. They use Structured Query Language (SQL) to query and manipulate data.

Examples of relational databases include:

  • MySQL
  • PostgreSQL
  • Oracle Database
  • Microsoft SQL Server

Relational databases are popular for their ability to manage large volumes of structured data and their support for transaction processing.

NoSQL Databases

NoSQL databases are designed to handle large volumes of unstructured or semi-structured data.

They are not based on the traditional relational data model, and use a variety of data models such as key-value, document, column-family and graph.

Examples of NoSQL databases include:

  • MongoDB
  • Cassandra
  • Couchbase
  • Neo4j

NoSQL databases are popular for their ability to handle big data and their support for horizontal scaling.

Graph Databases

Graph databases are designed to store and manage data in the form of nodes and edges, which represent entities and relationships between entities.

They are used for applications that require deep relationships between data, such as social networks or recommendation engines.

Examples of graph databases include:

  • ArangoDB
  • Neo4j
  • Amazon Neptune
  • OrientDB

Graph databases are popular for their ability to manage complex relationships between data and their support for fast traversal of graph data.

Column-Family Databases

Column-family databases store data in column families, which are groups of related columns. They are designed to handle large amounts of structured and semi-structured data, such as log data or time-series data. Examples of column-family databases include:

  • Apache Cassandra
  • HBase
  • ScyllaDB
  • Amazon DynamoDB

Column-family databases are popular for their ability to handle large volumes of data and their support for fast read and write operations.

In-Memory Databases

In-memory databases store data in memory instead of on disk.

They are designed to handle large volumes of data with fast read and write operations.

Examples of in-memory databases include:

  • Redis
  • Memcached
  • VoltDB
  • Apache Ignite

In-memory databases are popular for their ability to handle high-throughput workloads and their support for real-time data processing.

File-based Databases

File-based databases store data in files on disk. They are designed to be simple and easy to use, with minimal setup and configuration required.

Examples of file-based databases include:

  • SQLite
  • Microsoft Access
  • Berkley DB
  • LevelDB

File-based databases are popular for their ease of use and low cost of entry.

Choosing

Choosing the right data store for your application or system depends on many factors, including the type of data you are storing, the volume of data, the performance requirements, and the need for scalability and flexibility.

Message Queues

Message queues are a key component of modern distributed systems and are used to manage the flow of data between applications, services, and processes.

They provide a way to decouple different parts of a system and to ensure reliable delivery of messages.

Some popular message queue systems include RabbitMQ and Apache Kafka.

RabbitMQ

RabbitMQ is a widely-used open-source message broker that implements the Advanced Message Queuing Protocol (AMQP). It is written in Erlang and provides a scalable and reliable platform for distributing messages between applications and services. RabbitMQ supports a wide range of messaging patterns, including point-to-point, publish-subscribe, and request-reply.

Apache Kafka

Apache Kafka is a distributed streaming platform that is used for building real-time data pipelines and streaming applications. It provides a scalable and fault-tolerant platform for processing and storing streams of data in real-time. Kafka is designed to handle high-throughput and low-latency data streams and provides a wide range of tools and APIs for building real-time data pipelines.

Redis

Redis is an open-source in-memory data structure store that is often used as a message broker or as a database for caching and real-time applications. Redis supports a wide range of data structures, including strings, hashes, lists, and sets, and provides a number of features that make it well-suited for real-time applications, such as pub/sub messaging and transactions.

Other Message Queue Systems

There are many other message queue systems available, including Apache ActiveMQ, ZeroMQ, and Amazon Simple Queue Service (SQS).

The choice of message queue system depends on the specific needs and requirements of the application or system, including factors such as performance, scalability, reliability, and ease of use.

Processing Engines

Big data processing engines are designed to process and analyze large amounts of data in distributed environments.

These engines provide a scalable and fault-tolerant platform for processing data and can be used for a wide range of use cases, including batch processing, stream processing, and machine learning.

Apache Spark

Apache Spark is a widely-used big data processing engine that provides a unified analytics engine for large-scale data processing.

It supports a wide range of data sources and provides APIs for batch processing, stream processing, and machine learning.

Spark provides a scalable and fault-tolerant platform for processing data and can be used in a wide range of industries, including finance, healthcare, and e-commerce.

Apache Flink is a distributed processing engine for batch processing, stream processing, and machine learning.

It provides a unified programming model for batch and stream processing, and supports a wide range of data sources and sinks.

Flink provides a scalable and fault-tolerant platform for processing data and can be used for a wide range of use cases, including fraud detection, predictive maintenance, and real-time analytics.

Apache Beam

Apache Beam is an open-source unified programming model for batch and stream processing.

It provides a set of SDKs for Java, Python, and Go that can be used to build batch and stream processing pipelines.

Beam provides a portable and extensible platform for processing data and can be used with a wide range of data sources and sinks, including Apache Kafka, Google Cloud Pub/Sub, and Amazon S3.

Other Big Data Processing Engines

Other big data processing engines are available, including Apache Hadoop, Apache Storm, and Apache Samza.

The choice of big data processing engine depends on the specific needs and requirements of the use case, including factors such as performance, scalability, reliability, and ease of use.