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5.45 When should I use each isolation level if my cursor is not updatable?
Key points (continued)
- If the transaction you are using has a non-updatable cursor, consider the
following cases and use the appropriate isolation level.
- Use the RR isolation level if the transaction needs to retain all
locks until the end of the transaction. Use RR if the transaction
needs to view a consistent snapshot of the data at a single point in time,
especially if you need to make data modifications based on the values returned
by the cursor.
- Use the RC isolation level if the transaction simply needs to view a simple
snapshot of committed data and does not need to make data modifications
based on the values returned by the cursor.
- Use the RU isolation level if it is acceptable for the transaction to scan
through rows of uncommitted data in addition to committed data, and the
transaction does not need to make
data modifications based on the values returned by the cursor.
- If the transaction will only access data that cannot be modified by any user
(you know in advance that no user will ever change the data),
you can use the RU isolation level for optimal performance.
Page last updated on November 29, 1995
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