A growing app has a users table with millions of rows. You notice slow login queries filtering by username. Which combined approach best improves performance?
hard📝 optimization Q15 of 15
PostgreSQL - Performance Tuning
A growing app has a users table with millions of rows. You notice slow login queries filtering by username. Which combined approach best improves performance?
AStore usernames in a separate table without indexes.
BDrop all indexes and rely on sequential scans.
CAdd an index on <code>username</code> and analyze query plans regularly.
DIncrease server RAM without changing queries or indexes.
Step-by-Step Solution
Solution:
Step 1: Identify indexing as key for fast lookups
Adding an index on username helps queries find users quickly.
Step 2: Use query plan analysis to maintain performance
Regularly checking query plans helps spot slow parts and optimize further.
Final Answer:
Add an index on username and analyze query plans regularly. -> Option C
Quick Check:
Index + query plan analysis = best tuning [OK]
Quick Trick:Combine indexing with query plan checks [OK]
Common Mistakes:
Removing indexes causes slower queries
Ignoring query plan analysis
Relying only on hardware upgrades
Master "Performance Tuning" in PostgreSQL
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