SpringOne 2008 - Persistence Tuning for the Spring Environments by Tomas Risberg

a few best practices:

• get your DBA involved early
• take time to design your db: tables, indexes, data types, normalize, partition,... all have impact on the performance
  
• consider batch vs online. (consider native db-tools for loading)
  
• limit the number of rows / columns per table -> normalize
• avoid nulls in where clause (nulls are not indexed!)
• avoid starting with a wildcard in "like '%xyz'" tests (not indexed)
• select the proper transaction manager: JTA and XA is the slowest solution --> prefer plain JMS and native JDBC transactions
  
• avoid 'SERIALIZABLE' transaction isolation
• use the readonly-flag (JDBC) whenever possible.
• use a proper connection pool: Apache DBCP or Oracle Datasource Connection Pool (never use the 'standard' DriverManagerDatasource!)
• early test your connections at startup: JDBC 4: isValid() or "select 1 from dual;"
• use prepared statements --> optimized by db
• setFetchSize()
• use a RowMapper of BatchJdbcTemplate
• caching
• sql tuning: run EXPLAIN and ANALYZE commands
• tune Oracle memory: SGA (=global + sessions) and disk (blocks/files); put logs on separate volume