java.sql.Statement

java.sql.Statement is an SQL statement API.

**Table 1** Support status for java.sql.Statement
Method Name	Return Type	JDBC4 Supported or Not
addBatch(String sql)	void	Yes
clearBatch()	void	Yes
clearWarnings()	void	Yes
close()	void	Yes
closeOnCompletion()	void	Yes
execute(String sql)	Boolean	Yes
execute(String sql, int autoGeneratedKeys)	Boolean	Yes
execute(String sql, int[] columnIndexes)	Boolean	Yes
execute(String sql, String[] columnNames)	Boolean	Yes
executeBatch()	Boolean	Yes
executeQuery(String sql)	ResultSet	Yes
executeUpdate(String sql)	int	Yes
executeUpdate(String sql, int autoGeneratedKeys)	int	Yes
executeUpdate(String sql, int[] columnIndexes)	int	Yes
executeUpdate(String sql, String[] columnNames)	int	Yes
getConnection()	Connection	Yes
getFetchDirection()	int	Yes
getFetchSize()	int	Yes
getGeneratedKeys()	ResultSet	Yes
getMaxFieldSize()	int	Yes
getMaxRows()	int	Yes
getMoreResults()	Boolean	Yes
getMoreResults(int current)	Boolean	Yes
getResultSet()	ResultSet	Yes
getResultSetConcurrency()	int	Yes
getResultSetHoldability()	int	Yes
getResultSetType()	int	Yes
getQueryTimeout()	int	Yes
getUpdateCount()	int	Yes
getWarnings()	SQLWarning	Yes
isClosed()	Boolean	Yes
isCloseOnCompletion()	Boolean	Yes
isPoolable()	Boolean	Yes
setCursorName(String name)	void	Yes
setEscapeProcessing(boolean enable)	void	Yes
setFetchDirection(int direction)	void	Yes
setMaxFieldSize(int max)	void	Yes
setMaxRows(int max)	void	Yes
setPoolable(boolean poolable)	void	Yes
setQueryTimeout(int seconds)	void	Yes
setFetchSize(int rows)	void	Yes
cancel()	void	Yes
executeLargeUpdate(String sql)	long	No
getLargeUpdateCount()	long	No
executeLargeBatch()	long	No
executeLargeUpdate(String sql, int autoGeneratedKeys)	long	No
executeLargeUpdate(String sql, int[] columnIndexes)	long	No
executeLargeUpdate(String sql, String[] columnNames)	long	No
enableStreamingResults()	void	Yes

Using setFetchSize can reduce the memory occupied by result sets on the client. Result sets are packaged into cursors and segmented for processing, which will increase the communication traffic between the database and the client, affecting performance.
Database cursors are valid only within their transactions. If setFetchSize is set, set setAutoCommit(false) and commit transactions on the connection to flush service data to a database.
The LargeUpdate method can only be used in JDBC 4.2 or later.
enableStreamingResults() is a customized API for enabling streaming read. This API indirectly calls setFetchSize(Integer.MIN_VALUE). To enable the streaming read function, set enableStreamingQuery in the URL to true and call setFetchSize(Integer.MIN_VALUE) or enableStreamingResults(). Except that the streaming read function is enabled, the input parameter of setFetchSize() can only be a positive number or 0.