2005 - Everything on sharded clustered databases. A re-shard took years to complete.

Google Needs

  • Horizontally scaling database
  • ACID transactions with global consistency
  • No downtime
    • A minute of downtime on adwords cost millions of dollars

What is Cloud Spanner

Mission critical scaleable RDBMS.

  • Fully managed. Global scale
  • Traditional relational semantics: schemas, ACID transactions, SQL
  • Automatic, synchronous replication withing and across availability regions
  • Battle-tested within Google for 5+ years (adwords, google play)

Open Standards

  • Standard SQL (ANSI 2011)
  • Encryption, audit logging, identity and access management
  • Client libraries in popular languages (Java, Python, Go, Node.js etc)
  • JBDC driver

Types of Workloads

  • Transactional
    • Companies that have outgrown traditional RDBMS and have moved to NoSQL, but need transactional consistency
  • Scale-out
    • Companies currently sharding database because they need more read/write throughput than can be placed on 1 node
  • Global data plane
    • Companies and/or developers building applications that have global data and need strong consistency
  • Database consolidation
    • Companies that store their business data in multiple database products with variable maintenance overheads

Interleave Tables

  • Store tables ‘interleaved’ with each other for common data
  • Allows spanner to know to keep related data together in the same nodes
  • Reduces need for 2-phase commit
  • Create 1st table (CREATE TABLE Singers...) and interleave second table (CREATE TABLE Albums...INTERLEAVE IN Singers;)


  • Force use of indexes in a query (FROM TableName@{FORCE_INDEX=IndexName})
  • Monitoring metrics available from Spanner in Stackdriver