Question

What specific advantages [provide at least two] are identified by the paper for indexing databases with B-trees and why has the B-tree become a de facto standard for DBMS indexing?

Answer 1

Hi,

Now a days people are running with the time so they need fast computing machines/systems and they want speedy response from the servers. So obviously data is stored in the databases, it need to be retrieved as fast as it can. So DBA's will create an indexes on the tables which are much exposed to the users.

There are certain advantages if we create indexes on tables:
It helps you to reduce the total number of I/O operations needed to retrieve that data, so you don't need to access a row in the database from an index structure.
Offers Faster search and retrieval of data to users.
Indexing also helps you to reduce tablespace as you don't need to link to a row in a table, as there is no need to store the ROWID in the Index. Thus you will able to reduce the tablespace.
You can't sort data in the lead nodes as the value of the primary key classifies it.

Databases are indexed with btree's because of advantages like,
keeps keys in sorted order for sequential traversing
uses a hierarchical index to minimize the number of disk reads
uses partially full blocks to speed insertions and deletions
keeps the index balanced with a recursive algorithm

B-tree become a de facto standard for DBMS indexing because,
B-tree provides an efficient way to insert and read data. In actual Database implementation, the database uses both B-tree and B+tree together to store data. B-tree used for indexing and B+tree used to store the actual records. B+tree provides sequential search capabilities in addition to the binary search, which gives the database more control to search non-index values in a database.