# Use the appropriate getXXX and setXXX methods for the type

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.

Table 1. Mapping of java.sql.Types to SQL types
Recommended getXXX Method | java.sql.Types | SQL Types
--- | --- | ---
getLong | BIGINT | BIGINT
getBytes | BINARY | CHAR FOR BIT DATA
getBlob | BLOB | BLOB
getString | CHAR | CHAR
getClob | CLOB | CLOB
getDate | DATE | DATE
getBigDecimal | DECIMAL | DECIMAL
getDouble | DOUBLE | DOUBLE PRECISION
getDouble | FLOAT | DOUBLE PRECISION
getInt | INTEGER | INTEGER
getBinaryStream | LONGVARBINARY | LONG VARCHAR FOR BIT DATA
getAsciiStream, getUnicodeStream | LONGVARCHAR | LONG VARCHAR
getBigDecimal | NUMERIC | DECIMAL
getFloat | REAL | REAL
getShort | SMALLINT | SMALLINT
getTime | TIME | TIME
getTimestamp | TIMESTAMP | TIMESTAMP
getBytes | VARBINARY | VARCHAR FOR BIT DATA
getString | VARCHAR | VARCHAR
None supported. You must use XMLSERIALIZE and then the corresponding getXXX method. | SQLXML | XML

Parent topic: Performance tips and tricks
Related concepts
Use prepared statements with substitution parameters
Create indexes, and make sure they are being used
Ensure that table statistics are accurate
Increase the size of the data page cache
Tune the size of database pages
Avoid expensive queries
Tune database booting/class loading
Avoid inserts in autocommit mode if possible
Improve the performance of table functions
Configure Derby to use an in-memory database
Increase the concurrency of sequences
Shut down the system properly
Put Derby first in your classpath