Initially question was asked to mention the types of indexes.
Then asked about BITMAP INDEX and B-Tree Index
Answers were Sorted based on User's Feedback
Answer / slokh
Bitmap index is a type of index created on the basis of the
column having low cardinality like. index created on the
column like 'gender' etc.
B-tree or binary index is created on the column contains
wide range of values like 'name' column.
note:- more than one index is created on the table.
Is This Answer Correct ? | 9 Yes | 0 No |
Answer / brajesh kr.
Bitmap:- index is special kind of index that uses bitmap .
it significant space and performance advantage over
structure for such data. it is also useful for unique value
data. it use bit arrays and answer queries by performing
bitmap logical operations on these bitmap.
B-Tree:-databse server uses a b-tree strucruyre to organize
index information shows that afully developed b-treee index
is composed of that following
1.Oneroot nodes
2. Two or more branch nodes.
Is This Answer Correct ? | 1 Yes | 5 No |
What is the difference between mdf and ndf files?
Hi all, I am going to write oracle certification. Can anyone send me the dumps available if any for OCA exam? Its really very urgent, prompt response will help me alot..
I have a table with 1 million records out of which 10,000 records are of unique records, then if I will implement index, then which type of index shall I use and why shall I use?
What are the subsets of sql?
What is data control language?
Is foreign key mandatory?
What is a join?
How you can copy a file to file content and file to pl/sql table in advance pl/sql?
Explain raise_application_error.
what is bulk bind
What is a field in a database?
SELECT emp_num, years, SUM(salary) FROM sales UNION ALL SELECT emp_id, SUM(takehomepay) FROM marketing What error is present in the sample code above? 1. Queries being combined with the UNION ALL statement are not allowed to have SELECT lists with a different number of expressions. 2. You are not allowed to use aggregate functions within two queries joined by a UNION ALL statement. 3. The UNION ALL statement incorrectly combines the "years" result from the first query with the "SUM (takehomepay)" result from the second query. 4. Unless the UNION ALL statement is replaced with a UNION statement, the queries will return duplicates. 5. The "emp_id" column from the second query must be renamed (or aliased) as "emp_num" so that it corresponds to the column name from the first query. Otherwise, the queries will not execute.