Postgres is the master data for the directory. A new nomenclature (new product) has appeared in Postgres — should it appear in Redis?

If Postgres is the source of truth (master data) for the directory, then when a new nomenclature (new product) appears in Postgres, the data should be synchronized with Redis if Redis is used as a cache or for quick access to the directory.

Typically, one of the following approaches is implemented:

1. Event-driven synchronization — after adding a product to Postgres, an event is generated, which is processed by a service and updates Redis.
2. Periodic synchronization — data from Postgres is exported on a schedule and updates Redis.
3. Write-through cache — when writing to Postgres, Redis is updated simultaneously.

An example in Go (simplified):

// After inserting a product into Postgres
func AddProduct(product Product) error {
    err := insertIntoPostgres(product)
    if err != nil {
        return err
    }
    // Update Redis
    err = redisClient.Set(ctx, product.ID, product, 0).Err()
    return err
}

Thus, the new nomenclature will appear in Redis, ensuring data relevance.