For performance reasons, use the recommended getXXX method when retrieving values, and use the recommended setXXX method when setting values for parameters. JDBC is permissive. It lets you use java.sql.ResultSet.getFloat to retrieve an int, java.sql.ResultSet.getObject to retrieve any type, and so on. (java.sql.ResultSet and java.sql.CallableStatement provide getXXX methods, and java .sql.PreparedStatement and java.sql.CallableStatement provide setXXX methods.) This permissiveness is convenient but expensive in terms of performance. The following table shows the recommended getXXX methods for given java.sql (JDBC) types, and their corresponding SQL types.
http://db.apache.org/derby/docs/10.8/tuning/ctunperf98197.html
分享到：
相关推荐
Create two suclasses for individual automobile makers (for example, Ford and Chevy) and include appropriate setPrice() methods in each subclass. Finally, write a program that uses the Auto class and ...
appropriate if you have this basic background and want to learn how to use the scientific Python toolchain to investigate these topics. On the other hand, if you are comfortable with Python, perhaps ...
Perhaps the most common and familiar way that the results of medical ...with guidelines for use and interpretation of these statistics appropriate to the type of study that gives rise to the data.
This chapter focuses on graphical methods for solving optimization problems, which are particularly useful for visualizing and understanding the behavior of the objective function and constraints....
The book covers the breadth of activities and methods and tools that Data Scientists use. The content focuses on concepts, principles and practical applications that are applicable to any industry ...
Determine the appropriate size and type of the IPv6 allocation you require Apply current network management tools to IPv6 Use IPv6 renumbering methods that enable greater network scale and easier ...
But the principles and practices of software architecting–what the authors call the “science of hard decisions”–have been evolving for cloud, mobile, and other shifts. Now fully revised and ...
Appropriate for both introductory and advanced data mining courses, Data Mining: The Textbook balances mathematical details and intuition. It contains the necessary mathematical details for professors...
Determine the appropriate size and type of the IPv6 allocation you require Apply current network management tools to IPv6 Use IPv6 renumbering methods that enable greater network scale and easier ...
To facilitate quick learning, this Third Edition stresses using graphical methods to find appropriate models and to better understand them. In that spirit, most analyses and homework problems use ...
Chapter 6 discusses methods for creating your own blocks and using masks to customize their appearance and use. Chapter 7 describes subsystems whose execution depends on triggering signals. Chapter 8 ...
Specifically, it includes the use of the standard illuminants and the standard colorimetric observers; the reference standard for reflectance; the illuminating and viewing conditions; the ...
Careful consideration of the similarity invariances requires methods appropriate for non-Euclidean data analysis. In particular, multivariate statistical procedures cannot be applied directly, but ...
things like the last mail received and calculate how many are new for you. So, when using the JavaMail API, if you want this type of information, you have to calculate it yourself. IMAP IMAP is a...