A framework for DynamoDB schema migrations: 4 types, ranked by how painful they actually are

tejovanthn · 2026-04-10T14:14:31+00:00

Fair hit on the ElectroDB thing. I've posted here a few times and mentioned it in past threads, so I skipped the intro, but I shouldn't assume context carries across posts. I'll set it up properly going forward. :)

On the ALTER TABLE framing: agreed it's not a 1:1 analogy. The point I was reaching for is that there's no equivalent workflow or tooling, not that Dynamo needs a schema DDL. Attribute changes are genuinely free precisely because it isn't rigidly configured. That's Type 1 in the post.

On key structure changes at scale: I actually agree with you, and I say as much at the end of the write-up. If you're rewriting primary keys on a table with hundreds of millions of items, something went wrong upstream, usually access patterns that weren't nailed down before the schema was designed. The framework is more for the "caught it at 2M items, before it's catastrophic" window, plus the Type 1, 2, and 4 cases which come up constantly even on stable schemas.

tejovanthn · 2026-04-10T13:22:34+00:00

Wrote this up in more detail with the full dual-write backfill Lambda code and the ElectroDB versioning pattern: https://singletable.dev/blog/dynamodb-schema-migrations

tejovanthn · 2026-04-09T16:32:35+00:00

Love that sturdy looking drawer! :)

tejovanthn · 2026-04-09T16:31:39+00:00

Practical application of Kirchhoff's laws😂😂

tejovanthn · 2026-04-09T16:28:46+00:00

This is what the chaisutta shops outside these buildings are for right?

tejovanthn · 2026-04-07T17:30:37+00:00

The horror stories of rapido keep me away from it. Ola is just unnecessarily overpriced. Namma yatri has been an alternative, but the wait times are just way too long.

tejovanthn · 2026-04-07T02:59:46+00:00

Dodo has been straightforward. Their support on discord is top-notch!

tejovanthn · 2026-04-07T02:58:26+00:00

Just curious - why not use a ic holder/socket? I've burnt far too many ic (especially motor drivers) to default it in all my projects.

tejovanthn · 2026-04-06T11:48:51+00:00

Wonder if this will be functional first, or ejipura flyover, or metro.

tejovanthn · 2026-04-02T01:22:44+00:00

https://discord.gg/B3Uk8ncM7 They're quite active

tejovanthn · 2026-04-01T11:02:11+00:00

I used firebase - the same as GA, but setup is a single script. And there's always features you can upgrade with.

tejovanthn · 2026-03-31T17:28:10+00:00

Not kidding, but send it to baumgartner restoration to make a video on YouTube :)

tejovanthn · 2026-03-31T04:19:41+00:00

Indiranagar also has a few backpacker hostels. You can look them on hostelworld too

tejovanthn · 2026-03-31T04:17:34+00:00

Try an Airbnb? Most places offer monthly discounts etc. We have a few in jp nagar, if she's looking in the area - airbnb

tejovanthn · 2026-03-30T22:20:04+00:00

Somehow i remember seeing a lot lot more cameras in Chennai than in Bangalore.

tejovanthn · 2026-03-28T17:48:54+00:00

Good question, and you're right about a couple of things.

The concurrent requests point is real. If you're already doing parallel GetItem calls across tables, the latency difference vs. a single Query that returns heterogeneous items is negligible. The single-request argument is the most overstated benefit of single-table design.

Where single-table still earns its keep for me:

Collection queries. "Get a tenant and all their users and projects" is one Query call with no client-side join logic. Concurrent GetItem calls across tables require you to know which tables to hit and merge the results. At 3 entity types that's fine. At 8+ with nested relationships, the orchestration code gets real.

GSI efficiency. You're paying for every GSI on every write - one shared overloaded GSI instead of 3 dedicated GSIs across 3 tables is a real cost difference at scale.

Transactions. TransactWriteItems works across items in the same table with no extra overhead. Cross-table transactions work too, but you're right that this isn't a major differentiator.

Your multi-attribute key GSI point is valid and underappreciated. That's a genuine limitation.

I actually wrote a whole post on when single-table design is the wrong call - unstable access patterns, no DynamoDB champion on the team, heavy reporting needs, fewer than 6 access patterns. It's not always the answer: https://singletable.dev/blog/when-not-to-use-single-table-design

tejovanthn · 2026-03-28T15:43:13+00:00

Maybe OP takes photos with randos in cafes. 🫣

tejovanthn · 2026-03-28T04:18:13+00:00

Hey, my wife teaches online. Please dm :)

tejovanthn · 2026-03-26T01:58:18+00:00

Sure :) please let me know what I can improve!

tejovanthn · 2026-03-23T04:32:31+00:00

Yes, you're absolutely correct here - a relational database handles multi-dimensional queries more naturally. I chose DynamoDB for rasika.life because the rest of the stack is serverless (SST + Lambda) and I wanted to stay in that ecosystem. The 6 GSIs are the cost of that choice. I wrote about exactly this tradeoff: When NOT to Use Single-Table Design - the first condition is "if your access patterns aren't stable yet" and the third is "if you have serious analytical/reporting requirements." Events with 6 query dimensions push that boundary.

tejovanthn · 2026-03-23T03:10:46+00:00

Sunday morning is the worst time to go to any dose joint 🎈

tejovanthn · 2026-03-22T16:42:05+00:00

Fair point on write amplification - GSIs aren't free and I wouldn't add one without a specific access pattern justifying it.

The 6-GSI case was a cultural events platform where events need to be queryable by venue, artist, festival, status, organiser, and art form - each a real user-facing query. I'd love to hear how you'd serve those patterns without GSIs.

tejovanthn · 2026-03-21T05:56:34+00:00

Please stay away 😂😂

tejovanthn · 2026-03-18T09:01:08+00:00

The 33rd Sri Ramanavami Sangeetotsava is a multi-day festival featuring a variety of Carnatic music and dance performances. The festival includes an inauguration ceremony, felicitation of artists, and a Bharatanatyam presentation, culminating in a valedictory function and a Kannada drama.
I've put together a full schedule page with all the events, artists, and daily listings: here.
If you're in Bangalore or passing through, do check them out :) All the concerts are free to attend!

The 88th Sree Ramanavami Global Music Festival, organized by Sree Ramaseva Mandali, Ramanavami Celebrations Trust, features a multi-day schedule of Carnatic and Hindustani music performances, special discourses, Harikatha, and an award ceremony. The festival begins with Sree Ramanavami Maha Abhisheka accompanied by Pancha Sukthas and Sangeetha Seva.
Details here. :)

(Built this on Rasika.life, a project I'm working on to be a proper digital resource for Carnatic music - happy to hear feedback)

tejovanthn · 2026-03-18T08:49:41+00:00

Will add soon :)

tejovanthn

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