Scrollable Cursors and Transaction Isolation

The following table lists the factors governing the visibility of changes.

Changes made by:	Visibility depends on:
Cursor	Cursor type, cursor implementation
Other statements in same transaction	Cursor type
Statements in other transactions	Cursor type, transaction isolation level

These factors are illustrated here.

Visibility of changes

The following table summarizes the ability of each cursor type to detect changes made by itself, by other operations in its own transaction, and by other transactions. The visibility of the latter changes depends on the cursor type and the isolation level of the transaction containing the cursor.

	Self	Own Txn	Othr Txn (RU [a])	Othr Txn (RC [a])	Othr Txn (RR [a])	Othr Txn (S [a])
Static
Insert	Maybe [b]	No	No	No	No	No
Update	Maybe [b]	No	No	No	No	No
Delete	Maybe [b]	No	No	No	No	No
Keyset -driven
Insert	Maybe [b]	No	No	No	No	No
Update	Yes	Yes	Yes	Yes	No	No
Delete	Maybe [b]	Yes	Yes	Yes	No	No
Dynamic
Insert	Yes	Yes	Yes	Yes	Yes	No
Update	Yes	Yes	Yes	Yes	No	No
Delete	Yes	Yes	Yes	Yes	No	No

[a] The letters in parentheses indicate the isolation level of the transaction containing the cursor; the isolation level of the other transaction (in which the change was made) is irrelevant.

RU: Read uncommitted
RC: Read committed
RR: Repeatable read
S: Serializable

[b] Depends on how the cursor is implemented. Whether the cursor can detect such changes is reported through the SQL_STATIC_SENSITIVITY option in SQLGetInfo.