fix: don't drop the Describe response on deferred transactions#1231
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levkk merged 1 commit intoJul 19, 2026
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Fixes pgdogdev#1196. A deferred BEGIN/COMMIT/ROLLBACK now answers the client's Describe message (ParameterDescription + NoData for a statement, NoData for a portal) instead of dropping it, which broke extended-protocol clients.
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Rebased onto latest main. Turns out my branch was a commit behind and missing #1232 (hot mutex in comms), which lines up with that checkout timeout in test_schema_sharding. Pretty sure it was unrelated to this change, so hopefully the rebase sorts it out. Hope it's green now |
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Good stuff, thanks! |
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Fixes #1196.
Problem
When the query parser defers a transaction-control statement (
BEGIN/COMMIT/ROLLBACK) because no server is attached yet,extended_transaction_replybuilds the reply but ignores the client'sDescribe. Extended-protocol clients (tokio-postgres and friends) get noParameterDescription/NoDataand abort withunexpected message from server.Fix
Answer the
Describe. Always sendingNoDataisn't enough: a statement describe ('S') must be answered withParameterDescriptionfirst. tokio-postgres sends one while preparing and expectsParameterDescriptionbefore anything else.So:
Describe→ParameterDescription+NoDataDescribe→NoDatamatching the extended-query protocol for utility statements (no params, no rows).
Tests
The existing
tokio_postgrestests only runSELECT/INSERT/COPY, so nothing exercised transaction control over the extended protocol. Addedtokio_postgres/transaction.rs, plus protocol-level unit tests inquery_engine/test/extended_transaction.rs.