Using lock table, PL-SQL Programming

Assignment Help:

Using LOCK TABLE

You use the LOCK TABLE statement to lock the whole database tables in the specified lock mode so that you can share or deny the access to them. For illustration, the statement below locks the emp table in the row share mode. The Row share locks permit concurrent access to the table; they avoid other users from locking the whole table for the restricted use. The Table locks are released when your transaction issues a commit or rollback.

LOCK TABLE emp IN ROW SHARE MODE NOWAIT;

The lock mode determines what other locks can be located on the table. For illustration, many users can obtain the row share locks on the table at the same time, excluding only one user at a time can obtain an exclusive lock. Whereas one user has an exclusive lock on the table, no other users can insert, delete, and update rows in that table.


Related Discussions:- Using lock table

Iterative control: loop statement, Iterative Control: LOOP  Statements T...

Iterative Control: LOOP  Statements The LOOP statement executes a series of statements multiple times. There are 3 forms of LOOP statements: LOOP, WHILE-LOOP, & FOR-LOOP. LOOP

Cursor variables in pl sql, Cursor Variables:   To execute the multi-...

Cursor Variables:   To execute the multi-row query, the Oracle opens an unnamed work region that stores the processing information. You can use an explicit cursor that names

Maintain an audit trail of product table changes, The accuracy of product t...

The accuracy of product table data is critical and the Brwebean's. owner wants to have an audit file that contains information regarding all DML activity on the BB_PRODUCT table. T

Deriving predicates from predicates in sql, Deriving Predicates from Predic...

Deriving Predicates from Predicates in SQL The corresponding section in the theory book describes how predicates can be derived from predicates using (a) the logical connectiv

Example of cast operator - sql, Example of Cast Operator So long as C...

Example of Cast Operator So long as CAST is used as shown, we could obtain the total marks for each exam in similar fashion, using SUM (Mark) AS TotalMarks. However, this giv

Declaring a cursor, Declaring a Cursor The Forward references are not ...

Declaring a Cursor The Forward references are not allowed in the PL/SQL. Therefore, you must declare a cursor before referencing it in other statements. Whenever you declare a

Existential quantification - sql, Existential Quantification - SQL Ex...

Existential Quantification - SQL Existential quantification-stating that something is true of at least one object under consideration-can be expressed by OR(r,c), meaning tha

Keyword and parameter description - cursors, Keyword and Parameter Descript...

Keyword and Parameter Description select_statement: This is a query which returns a result set of the rows. Its syntax is such that of select_ into_statement without the IN

Advantages of invoker rights, Advantages of Invoker Rights The Invoker-...

Advantages of Invoker Rights The Invoker-rights routines centralize the data retrieval. They are particularly helpful in applications which store data in various schemas. In su

When or then key constraints, WHEN or THEN Key Constraints Suppose a t...

WHEN or THEN Key Constraints Suppose a table has two columns representing a period of time throughout which the information conveyed by the other columns is recorded as having

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd