Internal errors while inserting from geojson

[controversial]

What happens?

I’m using duckdb-wasm with the spatial extension loaded, and repeatedly running a query of the form:

INSERT INTO segments (id, geom, a, b, recorded_at_z)
SELECT id, geom, a, b, z FROM ST_Read('previously-registered-file.geojsonl')
ON CONFLICT (id) DO UPDATE SET
  geom = EXCLUDED.geom,
  recorded_at_z = EXCLUDED.recorded_at_z
WHERE segments.recorded_at_z < EXCLUDED.recorded_at_z;

I’m frequently seeing errors from within duckdb-wasm like the following:

• TransactionContext Error: Failed to commit: Trying to read past end of buffer
• TransactionContext Error: Conflict on tuple deletion!
• RuntimeError: memory access out of bounds
• TransactionContext Error: Cannot perform IO in in-memory database — CreateBlock!

---

the purpose is to ingest a large amount of geospatial data into a queryable form as it loads incrementally from map vector tiles. Each geojson file often contains hundreds (up to a few thousand) of features, and each feature becomes its own record in duckdb.

I’m not sure whether these errors arise as a result of one issue or multiple, but I am seeing all of these errors from the same query (when run with different data)

To Reproduce

I “recorded” the registered files and the executed queries executed for a single session that displays several of these errors in order to create a reliable minimal reproduction.

memory-access-repro.zip

Here,

• files.json contains content that was “registered” as files to read
• queries.json contains queries that were run that produced the error(s)
• the included index.js loads duckdb, registers each of the files, and runs the recorded queries in sequence. This is a simple entrypoint that “replays” the sequence of queries that leads to the errors.

Running index.js reliably produces the errors I saw earlier; the set of conditions leading to the errors appears to be deterministic.

Browser/Environment:

Chrome 136

Device:

macOS 15.5 (Darwin 24.5.0 arm64 arm)

DuckDB-Wasm Version:

1.29.1-dev132.0

DuckDB-Wasm Deployment:

bundled

Full Name:

Luke Taylor

Affiliation:

N/A; using for my own purposes for personal projects