Lesson Notes By Weeks and Term - Senior Secondary 3
Dense and sparse index
Dense and sparse index
Term: 1st Term
Week: 4
Class: Senior Secondary School 3
Age: 17 years
Duration: 40 minutes of 2 periods each
Date:
Subject: Data Processing
Topic:- Dense and sparse index
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, pictures, Data Processing for senior Secondary Education by Hiit Plc, WAPB Computer Studies for Senior Secondary I by Adekunle et al, On-line Materials.
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
|
PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
|
STEP 1 INTRODUCTION |
The teacher reviews the previous lesson on the clustered and unclustered indexes |
Students pay attention |
|
STEP 2 EXPLANATION |
He defines dense and sparse index
|
Students pay attention and participates |
|
STEP 3 DEMONSTRATION |
He distinguishes between dense and sparse index |
Students pay attention and participate |
|
STEP 4 NOTE TAKING |
The teacher writes a summarized note on the board |
The students copy the note in their books |
NOTE
DENSE VERSUS SPARSE INDEXES
DENSE INDEX
This is said to be dense if it contains (at least) one data entry for every search key value that appears in a record in the indexed file.
In a dense index, index record appears for every search key value in the file or table. That is every search key in the index column has a particular record it will point to in the table or file.
A Sparse Index contains one entry for each page of records in the data file. The index record contains the search key and a pointer to the first data record with that search key value. A Sparse index must be clustered and it is smaller than a dense index.
EVALUATION: 1. Distinguish between dense index and sparse index
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively