Why Redis List Works Well for Search History in SmartNote

In SmartNote, search history is a high-frequency, short-lifecycle data pattern.

Characteristics of search history#

It usually has these properties:

• frequent writes
• fast read expectations
• no complex relational query requirement
• mostly recent N entries only

MySQL can store this, but it is often unnecessary overhead for this pattern.

Why Redis List is a good fit#

List naturally models ordered recent history.

Typical key design:

• search:history:user:{userId}

Common operations:

• LPUSH to insert newest query
• LTRIM to keep recent N entries
• optional dedup logic before insert

This keeps retrieval simple and fast.

Handling duplicates#

A practical approach:

1. remove existing same query
2. push new query to the head
3. trim to fixed size

This preserves recency while avoiding noisy repeats.

Expiration strategy#

Depending on product need, set TTL for automatic cleanup if long-term history is not required.

Closing#

Redis List is not universal, but for recent search history it is usually a clean and cost-effective choice: simple data model, fast operations, and predictable maintenance.