Bird
0
0

How can combining EXPLAIN with index creation improve query performance in a large database?

hard📝 Application Q9 of 15
SQL - Indexes and Query Performance
How can combining EXPLAIN with index creation improve query performance in a large database?
AEXPLAIN automatically creates indexes for slow queries
BEXPLAIN shows missing indexes; creating them speeds up data access
CIndexes slow down queries, so EXPLAIN suggests removing them
DEXPLAIN replaces the need for indexes entirely
Step-by-Step Solution
Solution:
  1. Step 1: Use EXPLAIN to identify slow parts

    EXPLAIN shows where full scans happen due to missing indexes.
  2. Step 2: Create indexes to improve those parts

    Adding indexes speeds up data retrieval for those queries.
  3. Final Answer:

    EXPLAIN shows missing indexes; creating them speeds up data access -> Option B
  4. Quick Check:

    EXPLAIN + indexes = faster queries [OK]
Quick Trick: Use EXPLAIN to find missing indexes to add [OK]
Common Mistakes:
  • Thinking EXPLAIN creates indexes automatically
  • Believing indexes always slow queries
  • Assuming EXPLAIN replaces indexes

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More SQL Quizzes