In a keyset-driven cursor, the order and the membership of rows in the result set are fixed at open time, but changes to values may be made by the cursor owner. Committed changes made by other users are visible. If a change affects a row’s order, or results in a row no longer qualifying for membership, the row does not disappear or move unless the cursor is closed and reopened. If the cursor remains open, deleted rows, when accessed, return a special error code that says they are missing. Updating the key also causes the rows to be “missing.”
Inserted data does not appear, but changes to existing data do appear when the buffer is refreshed. With or without order by, the user can access rows by either relative or absolute position.
To access a row by relative position, move the cursor relative to its current position. For example, if the cursor is on row three and you want to access row eight, tell the cursor to jump five rows relative to its current position. The cursor jumps five rows to row eight.
To access a row by absolute position, tell the cursor the number of the row you want to access. For example, if the cursor is on row three and you want to access row eight, tell the cursor to jump to row eight.
