Sydney RunkleandGitHub 1a989f22bb fix(checkpoint-postgres): add column aliases to seed-blob branch of delta stage-2 UNION ALL (#7728) ...

## Summary

- Ports the langgraph API checkpointer fix to the OSS Postgres
checkpoint.
- The `'b'` (seed-blob) branch of `_build_delta_stage2_sql`'s `UNION
ALL` was missing column aliases (`AS _kind`, `AS checkpoint_id`, `AS
task_id`, `AS idx`).
- In PostgreSQL, `UNION ALL` column names are taken from the **first**
`SELECT`. When `channels_with_chain` is empty but `channels_with_seed`
is not (e.g. very first run of a DeltaChannel graph, or
`snapshot_frequency=1`), the `'b'` branch becomes the first `SELECT`, so
columns got default names (`text`, `null`) instead of the expected
aliases — causing `KeyError: '_kind'` in
`_build_delta_channels_writes_history`.

## Test plan

- [ ] Existing `checkpoint-postgres` delta channel tests pass (`make
test` in `libs/checkpoint-postgres`)
- [ ] Manually verified fix matches the correction suggested in the
upstream API PR review comment

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2026-05-06 14:36:30 -04:00

..

checkpoint/postgres

fix(checkpoint-postgres): add column aliases to seed-blob branch of delta stage-2 UNION ALL (#7728)

2026-05-06 14:36:30 -04:00

store/postgres

fix: re-use connection (#7220)

2026-03-18 13:31:46 -07:00