Physical Design and Storage Engines

Owned by Computer Science Department
Last updated: Aug 02, 2023
2 min read

Physical Design

  • Physical design in a database refers to the implementation details and configurations that govern how data is stored on the underlying storage media (e.g., disks). It includes decisions about how to arrange data in tables, what indexes to create, and how to partition the data to optimize performance.

  • Physical design is the actual implementation of the database schema and logical design, which focuses on defining relationships between entities and attributes.

Storage Engines

MySQL, an open-source relational database management system, supports various storage engines that offer different features, optimizations, and trade-offs to suit different use cases and data requirements. Each storage engine has its strengths and weaknesses, allowing developers and database administrators to choose the most appropriate one for their specific needs. Some of the main storage engines supported by MySQL include:

  1. InnoDB:

    • InnoDB is the default and most widely used storage engine in MySQL, known for its ACID (Atomicity, Consistency, Isolation, Durability) compliance and robust transaction support.

    • It offers row-level locking, which allows multiple transactions to access different rows simultaneously, enhancing concurrency and performance for heavily transactional workloads.

    • InnoDB also supports foreign keys, crash recovery, and automatic deadlock detection.

  2. MyISAM:

    • MyISAM is one of the earliest storage engines in MySQL and offers good performance for read-heavy workloads with little write activity.

    • It does not support transactions, row-level locking, or foreign keys, making it less suitable for applications requiring data integrity and concurrent writes.

    • MyISAM is often used for read-only or read-mostly scenarios, such as data warehousing or reporting databases.

  3. MEMORY (formerly HEAP):

    • The MEMORY storage engine stores data entirely in memory, making it extremely fast for read and write operations.

    • However, as it is an in-memory engine, data is not persistent, and it is lost when the MySQL server restarts.

    • The MEMORY engine is useful for temporary tables, caching, and high-performance lookup tables.

  4. NDB Cluster (MySQL Cluster):

    • NDB Cluster is a storage engine designed for high availability and scalability in a clustered environment.

    • It uses distributed architecture and data partitioning to provide real-time access to data with automatic failover and recovery.

    • NDB Cluster is well-suited for applications requiring high availability and low-latency access to data, such as telecommunications and online gaming.

  5. ARCHIVE:

    • The ARCHIVE storage engine is optimized for high compression and is suitable for scenarios where data is infrequently accessed but needs to be stored efficiently.

    • It does not support indexing or transactions, so it is best used for data archival and logging purposes.

  6. CSV:

    • The CSV storage engine stores data in comma-separated value (CSV) format files, making it easy to exchange data with other applications using CSV files.

    • However, it does not support indexing or transactions, so it is mainly used for data import and export operations.

  7. BLACKHOLE:

    • The BLACKHOLE storage engine accepts data for writing but does not actually store it. Instead, it acts as a "sink" for data that can be used for replication purposes.

Please note that the storage engines supported by MySQL may evolve over time, and new engines may be introduced or older engines may be deprecated or removed. When selecting a storage engine, it's essential to consider factors such as data integrity requirements, transaction support, concurrency, performance, and use case-specific characteristics to make an informed choice.