Kbase 18098: A query may read and lock more records than expected
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
13/07/1998 |
|
A query may read and lock more records than expected
Depending on your query and the indexes that you have
set up for your tables your query may be reading and
locking more records than you expected.
For example, the customer table in the sports database
has an index for the cust-num field and the city field
is not included in any index. The following query:
FOR EACH Customer WHERE Cust-Num > 10 AND City = "Boston":
DISPLAY Customer.Cust-Num Customer.Name.
END.
will read and share-lock ALL Customer records where the
Customer number is greater than 10 even if their city is not
equal to "Boston".
Customers that are displayed with the above query have a
Customer number greater than 10 and a city of Boston but
more Customer records were read and locked than necessary.