13. Understanding the Locking System : How the Locking System Works : Summary of Default Locks
 
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Summary of Default Locks
The following table describes what mode and level of lock is invoked by default when a query is issued.
Statement or Command
Comment
Mode
Level
CREATE INDEX
On base table:

On index:
X
X
X
Table lock
Control lock
Table lock
CREATE RULE
On base table:
X
Table lock
CREATE TABLE
On table:
X
X
Table lock
Control lock
CREATE VIEW
On view:

On base table:
X
X
X
Table lock
Control lock
Table lock
DROP
On table:
X
Table lock
GRANT
On base table:
X
Table lock
MODIFY
On table:
X
X
Table lock
Control lock
SELECT
For each table involved in the select:
IS
Table lock
SYSMOD
On database:
X
Database lock
UPDATE, INSERT, or DELETE
On table involved in update, insert, or delete:
IX
Table lock