Journal
Notes from real projects - AWS, DynamoDB, Rust, home servers, and whatever open source tool I'm currently building.
Articles
Dynoxide 1.5.0 release notes
Dynoxide 1.5.0 charges vector reads the way DynamoDB now does, fixes stream eventIDs repeating after a restart, and matches SearchVectors errors to AWS.
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DynamoDB changed how it bills a vector read
On 9th October a DynamoDB read of an item with a vector in it cost 2 read units. On 22nd October the same read cost 1. I can't find anything from AWS about it, and the 400KB limit still counts the vector the old way.
Read articleDynoxide 1.4.0: clean shutdowns and JSON Lines import
Dynoxide 1.4.0 is a smaller one. JSON Lines import thanks to Sam Chung, a clean way to stop an embedded server, and updates and scans that behave more like DynamoDB.
Read articleDynoxide 1.3.0: security fixes and fussier pagination
Dynoxide 1.3.0 ended up a bit bigger than I'd planned. A few of the DynamoDB quirks I worked through, two security fixes, and quieter test output thanks to an external contribution.
Read articleParity Suite 3.6 and a month of emulator fixes
Floci went from 337 failing tests to one in five weeks, and LocalStack and MiniStack both moved up a grade. Meanwhile AWS changed how transactions validate halfway through measuring 3.6.0, so that one never reached the board.
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DynamoDB vector search without embeddings
Serverless Advocate #85 had Lee Harding making the case that DynamoDB vector indexes are a nearest-neighbour tool, not an embeddings one, so I tried the geography case. A single geohash cell misses the nearest shop entirely. Read nine and it does not, which is the update at the end.
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Running DynamoDB vector search locally
Dynoxide has done DynamoDB vector search since 1.0.0. What I measured before building it, including the bit where AWS says the index is ready about fifteen minutes before it actually is, and the end of a rollout I have been watching since June.
Read articleParity Suite 3.0.0: measuring the wrong thing
The board scored emulators on a pass rate over what they attempted, so a score could jump 8 points without the engine changing a line. 3.0.0 replaces that with two figures, letter grades, and 56 new tests.
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When a DynamoDB vector index is actually ready
AWS's docs contradict each other about what searching a backfilling vector index does, describe a state the index never enters, and name a readiness signal that arrives too early. Here's what I measured instead.
Read articleWhat a write to an indexed DynamoDB table costs
Adding a GSI to a DynamoDB table doubles the cost of some writes and changes nothing about others, and which is which isn't well documented. So I measured it against real DynamoDB and pinned every number.
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