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Are stored procedures secure in MySQL?
In MySQL, stored routines (stored procedures and functions), triggers, events, and views execute within a security context which determines their privileges. MySQL uses DEFINER and SQL SECURITY characteristics to control these privileges.
Which statement Cannot be used in stored routine?
Stored routines cannot use LOAD DATA INFILE . Statements that return a result set cannot be used within a stored function. This includes SELECT statements that do not use INTO to fetch column values into variables, SHOW statements, and other statements such as EXPLAIN .
How are stored procedure secure?
Although SQL Server’s stored procedures help with code security by hiding the implementation of the business logic and even protecting against some kinds of SQL injection attacks — primarily those that use an operator such as AND or OR to append commands onto a valid input parameter value, simply wrapping the code into …
What is Definer in MySQL stored procedure?
The DEFINER clause specifies the MySQL account to be used when checking access privileges at routine execution time for routines that have the SQL SECURITY DEFINER characteristic. If the DEFINER clause is omitted, the default definer is the user who executes the CREATE PROCEDURE or CREATE FUNCTION statement.
What does it mean to lock a table in MySQL?
A lock is a flag associated with a table. MySQL allows a client session to explicitly acquire a table lock for preventing other sessions from accessing the same table during a specific period. A client session can acquire or release table locks only for itself.
What are the rules for lock acquisition in MySQL?
Rules for Lock Acquisition. If a table is to be locked with a read and a write lock, put the write lock request before the read lock request. Lock one table at a time until the session gets all locks. This policy ensures that table locking is deadlock free.
When does the lock tables statement have to wait?
If the LOCK TABLES statement must wait due to locks held by other sessions on any of the tables, it blocks until all locks can be acquired. A session that requires locks must acquire all the locks that it needs in a single LOCK TABLES statement.
What happens if you use alter table on a locked table?
If you use ALTER TABLE on a locked table, it may become unlocked. For example, if you attempt a second ALTER TABLE operation, the result may be an error Table ‘ tbl_name ‘ was not locked with LOCK TABLES. To handle this, lock the table again prior to the second alteration.