Consider a relational table $r$ with sufficient number of records, having attributes $A_1, A_2, \dots ,A_n$ and let $1 \leq p \leq n$. Two queries $Q1$ and $Q2$ are given below.
The database can be configured to do ordered indexing on $A_p$ or hashing on $A_p$. Which of the following statements is TRUE?
Have you mistakenly written the word "too" in the statement "Hashing works well on the 'equal' queries, while ordered indexing works well better on range queries too"
Hey Actually I am not getting the language
Hashing will outperform ordered indexing on Q1??
Here hashing will be work fine for same value data. while B+ tree works for sequential as well as duplicate data.
Typically, ordered indexing is used unless it is known in advance that range queries will be infrequent, in which case hashing is used like Q2:πA1,…,Ap(σc1≤Ap≤c2(r)) . Hash organizations are particularly useful for temporary files created during query processing, if lookups on a key value are required and no ranges queries will be performed like Q1:πA1,…,Ap(σAp=c(r)).
c is correct
yes sir TRUE... working on it :). But this...