Tag
Databases
3 posts tagged Databases.
Spanner: What Google's Globally-Distributed Database Paper Actually Says
Spanner achieves external consistency across a globally-distributed database using atomic clocks and GPS receivers. The insight isn't exotic hardware — it's that bounded clock uncertainty lets you make a specific, provable guarantee about transaction ordering that 'eventually consistent' databases can't offer.
HNSW: What the Vector Similarity Search Paper Actually Says
Every vector database runs HNSW under the hood. Most engineers tune M and ef_construction without understanding what they're actually trading off. The paper rewards a close read.
Cassandra: What the Paper Actually Says
We had a Cassandra cluster where DELETE operations made reads progressively slower until queries timed out. Adding more disk space made it worse. The root cause is described precisely in the 2009 paper — but only if you understand that Cassandra cannot actually delete data.