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!
Creation of Indexes
Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically.
Manually: User can form non-unique indexes on columns to speed up access time to rows.
Example: The following commands produce index on employee name and employee name + department number respectively.
CREATE INDEX EMP_ENAME_IDX ON EMP (ENAME);
CREATE INDEX EMP_MULTI_IDX ON EMP (ENAME, DEPTNO);
Finding facts about created indexes: The data dictionary have the name of index, table name and column names. For instance, in Oracle a user-indexes and user-ind-columns see contains the details about user formed indexes.
Remove an index from the data dictionary:
DROP INDEX EMP_ENAME_IDX;
Indexes cannot be modified.
Define Radix conversion method One clever way to transform binary numbers to BCD notation (binary-coded decimal) is the "double dabble algorithm". It can be adapted to transfo
What are called journaling file systems? File systems that support log disks are known as journaling file systems.
Mappings between Levels and Data Independence The 3 levels of abstraction in the database do not exist separately of each other. There must be some correspondence, or mapping
limitations and benefits in database tecknowlagy
Define Thomas write rule Thomas' write rule: The Thomas' write rule is a modification of timestamp-ordering protocol for concurrency control. Assume that transaction T i issue
What is called as recursive partitioning? The system repeats the splitting of the input unless each partition of the build input fits in the memory. Such partitioning is known
why older data models are being replaced by new data models.
Use a Set operator to create a list of academics who have written or co-written less than 5 papers and also have greater than 3 interests. List their academic number in the output.
What is schema
What is meant by log-based recovery? The most widely used structures for recording database changes is the log. The log is a sequence of log records, recording all the update a
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