hard20 pts · first answer countsindexingpostgresql

Index ignored because of a function

There is a B-tree index on users(email), but WHERE lower(email) = 'asha@example.com' still does a sequential scan in PostgreSQL. What is the right fix?

A.Create an expression index ON users (lower(email)), or store emails in a citext columnB.Run REINDEX on the existing email indexC.Set enable_seqscan = off in postgresql.conf for all sessionsD.Increase shared_buffers so the whole table fits in memory

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