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5.1 TurboIMAGE locking: mode 5 user
Reading from a data set without a predicate selects all rows
NOTE that each of the above SELECT statements does not contain
a WHERE clause, so all rows in each data set will be returned.
Key points
- A MODE 5 user only has the capability to read TurboIMAGE data.
- The
WHERE clause of a SELECT statement contains a search condition that
consists of at least one predicate. A predicate is a comparison of
expressions that evaluates to a value of TRUE, FALSE, or unknown. If a
predicate evaluates to TRUE for a row, the row qualifies; otherwise, the row
is not operated on.
- When a
SELECT statement does not contain a WHERE clause, all rows qualify.
- Locks on TurboIMAGE data are never acquired by a MODE 5 user, whether or
not a predicate is used.
Reading from a data set with a predicate only selects a subset of rows
NOTE that the above SELECT statement contains a WHERE clause,
so only a subset of rows will be returned.
Page last updated on November 29, 1995
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