Types of locks in database ?

Answer Posted / lakshminarayana reddy

2 types
1. Implicit locks: oracle automatically locks the rows
whenever user performs DML operations.
2. Explicit locks: provided by user.
2 tpyes a) Row level locks: used to lock selected rows
of table.It is imposed by "for update" clause in select.
b) Table level locks: used to lock compleate
table. 3 models 1) share mode
2) share update
3) exlcusive mode

Is This Answer Correct ?    92 Yes 26 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is difference between cursor and trigger?

761


What are the uses of merge?

896


What is pl sql block in dbms?

708


What is synchronized subquery?

824


First round ------------------- - Procedure - Packages - Views - Virtual tables - Can we use dcl with in function? - Joins and few scenarios - Triggers and its type - Pragma, type and its functionality - How to create db link in oracle - Materialized view - How to find duplicate values from table? - Cursor and its functionality - Write a script to display friday and its date from a entire year. - Exception Handling Second round ------------------------ Gave a scenario like. Need to write a function to perform. When user try to change a password. It must not be last five password and a given password can be combination of characters, symbols, upper and lower case.

1335






What is the difference between rollback and rollback to statements?

806


What are the 3 modes of parameter?

865


What is difference between function and trigger?

719


Is pl sql better than sql?

719


What is a record in pl/sql?

764


What is plpgsql language?

713


What are character functions in sql?

667


Which is the correct statement about truncate and delete?

757


How do I delete a trigger?

723


what is the different between now() and current_date()? : Sql dba

703