oracle.jdbc.driver.ROWID 사용하기.

Rule Base Optimizer 랭킹

Path 1 : Single Row by Rowid
Path 2 : Single Row by Cluster Join
Path 3 : Single Row by Hash Cluster Key with Unique or Primary Key
Path 4 : Single Row by Unique or Primary Key
Path 5 : Clustered Join
Path 6 : Hash Cluster Key
Path 7 : Indexed Cluster Key
Path 8 : Composite Index
Path 9 : Single-Column Indexes
Path 10 : Bounded Range Search on Indexed Columns
Path 11 : Unbounded Range Search on Indexed Columns
Path 12 : Sort-Merge Join
Path 13 : MAX or MIN of Indexed Column
Path 14 : ORDER BY on Indexed Column
Path 15 : Full Table Scan

oracle.sql.ROWID

Statement stmt = conn.createStatement();

// Query the employee names with "FOR UPDATE" to lock the rows.
// Select the ROWID to identify the rows to be updated.

ResultSet rset =
stmt.executeQuery ("SELECT ename, rowid FROM emp FOR UPDATE");

// Prepare a statement to update the ENAME column at a given ROWID

PreparedStatement pstmt =
conn.prepareStatement ("UPDATE emp SET ename = ? WHERE rowid = ?");

// Loop through the results of the query
while (rset.next ())
{
String ename = rset.getString (1);
oracle.sql.ROWID rowid = rset.getROWID (2);    // Get the ROWID as a String

pstmt.setString   (1, ename.toLowerCase ());
pstmt.setROWID (2, rowid);                            // Pass ROWID to the update statement

pstmt.executeUpdate ();                               // Do the update
}