Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
ROWID The ROWID returns the rowid (binary address) of a row in the database table. You can use the variables of the type UROWID to store rowids in a readable format. In the il
ALTER TABLE bb_basketitem ADD CONSTRAINT bitems_qty_ck CHECK (quantity BEGIN INSERT INTO bb_basketitem VALUES (88,8,10.8,21,16,2,3); END; Brewbean’s wants to add a check
Substitution and Instantiation - SQL It shows how NULL might appear in substitution for a parameter of a predicate and how it might thus participate in instantiation of that p
What Is a Record ? A record is a group of related data items that stored in the fields, each with its own name and datatype. Assume that you have different data about an em
Case Sensitivity Similar to all the identifiers, the variables, the names of constants, and parameters are not case sensitive. For illustration, PL/SQL considers the following n
Loop Labels Like the PL/SQL blocks, loops can also be labeled. The label, an undeclared identifier enclosed by double angle brackets, should appear at the beginning of the LOOP
Question: (a) In the context of database security explain how the following database features help to enforce security in the database system: (i) Authorisation (ii) Access
Example of ADD CONSTRAINT in SQL Example: Alternative formulation for MAX_ENROLMENTS ALTER TABLE IS_ENROLLED_ON ADD CONSTRAINT MAX_ENROLMENTS CHECK ((SELECT COUNT (*)
Parameter and Keyword Description: procedure_name The user-defined procedure is declared by this construct. parameter_name: This identifies the formal parameter t
LONG and LONG RAW You use the LONG datatype to store the variable-length character strings. The LONG datatype is such as the VARCHAR2 datatype, except that the maximum length o
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd