{
  "patent_number": "US 9280591",
  "country": "US",
  "title": "How Databases Keep Read-Only Copies Up-to-Date",
  "original_title": "Efficient replication of system transactions for read-only nodes of a distributed database",
  "summary": "Amazon's 2016 patent describes a system for efficiently updating read-only copies of a distributed database by sending specific change notifications, ensuring read-only nodes show accurate data.",
  "what_it_does": "This patent details how a distributed database system manages updates across multiple nodes. When a change is made to the main database (the read-write node), the system breaks down the update into smaller steps called 'system transactions.' For each transaction, it generates 'change notifications' that list exactly what needs to be altered. Crucially, it marks the very last notification for each transaction. These notifications, including the final one, are then sent to read-only nodes (read replicas). This 'last change' notification tells the read-only nodes precisely when they can present a consistent, updated view of the database to users requesting data, ensuring they don't show outdated information while an update is still being applied.",
  "what_it_does_not_cover": [
    "Does not cover systems where read-only nodes are updated without specific 'change notifications' indicating the exact modifications.",
    "Does not cover systems that don't identify a specific 'last change' notification to signal the completion of a transaction.",
    "Does not cover scenarios where read-only nodes are updated by sending the entire database state rather than incremental changes.",
    "Does not cover systems where read-only nodes cannot determine a consistent database state for read requests based on the received notifications.",
    "Does not cover updates to read-only nodes that are not part of a larger distributed database system."
  ],
  "filed": "2013-09-20",
  "granted": "2016-03-08",
  "expires": null,
  "status": "active",
  "holder": "Amazon Technologies Inc",
  "holder_url": "https://patentbrief.org/company/amazon-technologies-inc",
  "inventors": [
    {
      "name": "Tengiz Kharatishvili",
      "url": "https://patentbrief.org/inventor/tengiz-kharatishvili"
    },
    {
      "name": "Pradeep Jnana Madhavarapu",
      "url": "https://patentbrief.org/inventor/pradeep-jnana-madhavarapu"
    },
    {
      "name": "Anurag Windlass Gupta",
      "url": "https://patentbrief.org/inventor/anurag-windlass-gupta"
    }
  ],
  "times_cited": 108,
  "tags": [
    "software",
    "telecommunications",
    "consumer_electronics",
    "semiconductors"
  ],
  "abstract": "A distributed database system may efficiently replicate system transactions one or more read-only nodes. An update to a distributed database may be received. One or more system transactions may be performed to apply the update. For each system transaction, one or more change notifications may be generated which indicate changes to be applied in order to perform the system transaction. A particular one of the change notifications may be identified as the last change to be applied in order to complete the system transaction. The change notifications may be sent to one or more read-only nodes. The read-only nodes may process read requests for the distributed database system. The identified change notification may indicate to the read-only nodes the last change to be applied prior to presenting a state of the database that includes the system transaction when servicing read requests.",
  "url": "https://patentbrief.org/patent/us/9280591/amazon-emr-elastic-mapreduce",
  "markdown_url": "https://patentbrief.org/patent/us/9280591/amazon-emr-elastic-mapreduce/md",
  "google_patents_url": "https://patents.google.com/patent/US9280591",
  "relatedPatents": []
}