Part of the reason for MySQL’s blazing performance is its fully multithreaded architecture, which allows multiple concurrent accesses to the database. This multithreaded architecture is the core of the MySQL engine, allowing multiple clients to read the same database simultaneously and providing a substantial performance gain. The MySQL code tree is also structured in a modular, multilayered manner, with minimum redundancies and special optimizers for such complex tasks as joins and indexing.
MySQL also includes a query cache, which can substantially improve performance by caching the results of common queries and returning this cached data to the caller without having to re-execute the query each time. This is different from competing systems such as Oracle, in that those systems merely cache the execution plan, not the results. However, they still need to execute the query, including all joins, and re-retrieve the query results on every run. MySQL benchmarks claim that this feature improves performance by more than 200 percent, with no special programming required on the part of the user2. It is worth noting that MySQL’s designers initially left out many of the features that cause performance degradation on competing systems, including transactions, referential integrity, and stored procedures. These features typically add complexity to the server and result in a performance hit. User requests for these features have, however, resulted in their inclusion in newer versions of the product.
Source of Information : MCGraw Hill - SQL the Complete Reference 3rd Edition
MySQL also includes a query cache, which can substantially improve performance by caching the results of common queries and returning this cached data to the caller without having to re-execute the query each time. This is different from competing systems such as Oracle, in that those systems merely cache the execution plan, not the results. However, they still need to execute the query, including all joins, and re-retrieve the query results on every run. MySQL benchmarks claim that this feature improves performance by more than 200 percent, with no special programming required on the part of the user2. It is worth noting that MySQL’s designers initially left out many of the features that cause performance degradation on competing systems, including transactions, referential integrity, and stored procedures. These features typically add complexity to the server and result in a performance hit. User requests for these features have, however, resulted in their inclusion in newer versions of the product.
Source of Information : MCGraw Hill - SQL the Complete Reference 3rd Edition
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