# Recent questions tagged indexing

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Minimum number of Relations:- The Answer is $5$. Please see my Reason behind it:- 1. $R_6$ and $E_5$ CAN be merged giving $1$ relation we cant merge with $E_3$, because its a strong entity even though the participation is total. 2. $E_1$ and $E_4$ Gives total of $1$ ... , and $R_5$ can be merged. 4. $R_2$ will have separate table because of many to many (Doubt here) Hence total $5$ tables we got.
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Which of the following statement true about B tree and B+ tree index? Assume order of B tree node same as order of B+ tree node. A. B tree index has more levels than B+ tree index for large number of keys. B. B+ tree index has more levels than B tree ... + tree best for sequential access of records. D. B+ tree index nodes more than B+ tree for large number of keys. Please Explain every Point.
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Consider two relations R(A, B, C) and S(B, D) with R contains 5000 tupples stored in a sequential file sorted on attribute A and S contain 100000 tupples stored in a sequential file sorted on attribute B. Each block can hold 10 R tupples or 10 S tupples. Which one of the following index is ... in memory) A A dense index on R.B B A sparse index on R.B C A dense index on S.B D A sparse index on S.B
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Which of the following is dense index? Primary index Clustered index Secondary index Secondary non-key index
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What is the Difference between Primary and Clustering Index or both are actually the Same ?
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In this Question :- Let there is a Table named Stud_records with 3000 records of fixed length , each record size is 50 Bytes and records are stored in a block of size 512 Bytes , If secondary index is built on the key field of size 10 Bytes and a block pointer of size 5 Bytes , then ... = 88 Blocks The number of blocks in First level index = (88 * 15)/512 = 3 ???? Why am i wrong ?? Please Help?
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which of the statements are correct? A a clustered index offers much better performance than unclustered index for range queries B a clustered index istypically less expensive to manage than unclustered index
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I have read that clustered index is an index on ordered non-key field of DB. However, in SQL clustered index can be created on Primary key. Infact, by default primary key constraint automatically creates clustered index if one doesn't already exists on the table. So, is SQL clustered index different from the one defined in theory?
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B tree has minimum space utilization equals to 66.6%. explain?
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Maximum height of a B+ tree of order m with n key values is (With Derivation), the answer is known Logceil(m/2) N I tried deriving but had some trouble, could someone assist with the derivation or derivation process ?
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In a database file structure, the search key field is 9 bytes long, the block size is 1024 bytes, a record pointer is 7 bytes and a block pointer is 6 bytes. The largest possible order of a leaf node in a B+ tree implementing this file structure is
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Database file consist 1250 records. Block can hold either 3 records or (10 keys, 11 pointers). The maximum number of levels of index required for sparse B+ tree index for database file are ______.
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In a database file structure, the search key field is 9 bytes long, the block size is 1024 bytes, a record pointer is 7 bytes and a block pointer is 6 bytes. The largest possible order of a leaf node in a B+ tree implementing this file structure is ________. I am getting 63 as the answer, but in the solution, it's saying 64. Can anyone check?
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Database relation has 10,000 records. Block can hold either 4 records or 15 key and pointer pairs. If dense index used at 1st level and multilevel indexing is used for 1st level index then the minimum number of disk blocks required to store relation are ________. My ans : 2680 ??
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#DBMS Which of the following statements is/are true? (A) For any data file it is possible to construct two separate sparse first level indexes on different keys. (B) For any data file, it is possible to construct two separate dense first level indexes on different ... For any data file, it is possible to construct a sparse first level index and a dense second level index both should be useful.
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Every ________ index is Clustered a)primary b)secondary
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A file is organized so that the ordering of data record is same as or close to the ordering of data block in some index. Then that index is called Dense Sparse Clustered Unclustered Given answer is :- Sparse. Is it correct? This is similar to https://gateoverflow.in/8222/gate2015-1_24 with some variation i highlighted
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" For any data file, it is possible to construct two separate dense first level indexes on different keys. " How the above statement is true ??
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A file can have either one primary index or one clustered index but not both. True or false ? Give an answer with explanation.
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Q.Consider the following query : Select E.no,COUNT(*) FROM Employee E GROUP BY E.no If an index on eno is available,the query can be answered by scanning only the index if A) the index is only hash and clustered B) the index is only B+ tree and clustered C)index can be hash or B+ tree and clustered or non-clustered D)index can be hash or B+ tree and clustered
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Q.Consider a table that describes the customers: Customers(custid,name,gender,rating) The rating value is an integer in the range 1 to 5 and only two values(male and female) are recorded for gender.Consider the query "how many male customers have a rating of 5" ? The best indexing mechanism appropriate for the query is A) Linear hashing B)Extensible Hashing C)B+tree D)Bit-mapped index
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Records Size in bytes:- 30,75,40,65,50,20 Block Size:- 100 bytes If unspanning organization is used,then what is % of wastage in disk space?
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Does values in Leaf nodes of B+ tree repeats or ever leaf node has an unique value?
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Suppose size of block 1000 bytes search key of 12 bytes, pointer size 8 bytes. How many maximum records in DB file which can index by dense B+ tree of 2 levels?