Oracle 8i Locks

We are having problems with users locking each other throughout the day, in which one user is doing a select, and the other an update. In the last case, the user doing the following select statement acquired an exclusive lock:
SELECT "INVENTORY"."INVENTORY_ID",
SubStr( "INVENTORY"."RECEIPT_NUMBER", 1, 7 ) receipt_number,
"INVENTORY"."AGENCY_REPORT_YEAR",
"INVENTORY"."AGENCY_REPORT_NUMBER",
"INVENTORY"."AGENCY_REPORT_SUFFIX",
"INVENTORY"."NUMBER_OF_PACKAGES"
FROM "INVENTORY"
WHERE ( Upper ( receipt_officer_id ) Like '2026542%' )
Should an exclusive lock be placed here?
TIA
null

For the select statement there wont't be any locks on the table.
In the select statement are you using the SELECT ... FROM table FOR UPDATE OF also (The sql statement you have given does not have the update clause) then a Row Share lock will be held on the table.
Refer to the following URL http://technet.oracle.com/doc/oracle8i_816/server.816/a76965/c23cnsis.htm#9975
for the table lock modes that statements acquire and operations that those locks permit and prohibit.

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