JPA Performance, Don't Ignore the Database

JPA Performance, Don't Ignore the Database Database Schema Good Database schema design is important for performance. One of the most basic optimizations is to design your tables to take as little space on the disk as possible , this makes disk reads faster and uses less memory for query processing. Data Types You should use the smallest data types possible, especially for indexed fields. The smaller your data types, the more indexes (and data) can fit into a block of memory, the faster your queries will be. Normalization Database Normalization eliminates redundant data, which usually makes updates faster since there is less data to change. However a Normalized schema causes joins for queries, which makes queries slower, denormalization speeds retrieval. More normalized schemas are better for applications involving many transactions, less normalized are better for reporting types of applications.  You should normalize your schema first, then de-normalize later.  Applications often need to mix the approaches, for example use a partially normalized schema, and duplicate, or cache, selected columns from one table in another table. With JPA O/R mapping you can use the @Embedded annotation for denormalized columns to specify a persistent field whose @Embeddable ty...

Date: August, 28 2009
Url: http://www.java.net/blog/caroljmcdonald/archive/2009/08/28/jpa-performance-dont-ignore-database-0

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