Question

How can we use indices to speed up joins and merges

A) By removing indices before joining
B) By using broadcasting techniques
C) By ensuring indices are aligned and sorted
D) By converting indices to categorical data types

Answer 1

We can use indices to speed up joins and merges mainly by ensuring indices are aligned and sorted, which allows for efficient location and combination of related data during such operations.

Step-by-step explanation:

We can use indices to speed up joins and merges by ensuring indices are aligned and sorted, which is option C. Properly indexed data structures allow databases and data processing frameworks to quickly locate and combine related data points efficiently. For example, when both datasets in a join operation have sorted indices on the columns being joined, the database or software can perform the join more rapidly because it does not need to scan the entire dataset to find matching records.

Indices can serve as a sort of 'map' to direct the join or merge operation to the correct rows expeditiously. This is particularly beneficial for large datasets because it reduces the computational complexity significantly. By using indices effectively, the number of comparisons and data lookups required during the join can be minimized, leading to better performance and quicker results.