Databases · Senior · Question 63 of 75

For `WHERE tenant_id = $1 AND created_at > $2 ORDER BY created_at`, which composite index order is best?

1Two separate single-column indexes are always better
2(created_at, tenant_id)
✓Correct answer: (tenant_id, created_at): equality columns first, then the range or sort column

Explanation

With the equality column first, all rows for the tenant are adjacent and already sorted by time. A range column first would scatter each tenant across the index.

For `WHERE tenant_id = $1 AND created_at > $2 ORDER BY created_at`, which composite index order is best?

Explanation

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For WHERE tenant_id = $1 AND created_at > $2 ORDER BY created_at, which composite index order is best?

Explanation

Further reading

Test yourself

For `WHERE tenant_id = $1 AND created_at > $2 ORDER BY created_at`, which composite index order is best?