0B000ERRORTier 2 — Caution✅ HIGH confidence

invalid transaction initiation

Category: Invalid Transaction InitiationVersions: All Postgres versions

What this means

SQLSTATE 0B000 is raised when a transaction-control command (e.g., BEGIN) is issued in a context where a new transaction cannot be initiated — for example, inside a function that is already within an implicit transaction.

Why it happens

1Issuing BEGIN inside a PL/pgSQL function or trigger (which already runs inside a transaction)
2Attempting to start a nested transaction using BEGIN where only SAVEPOINTs are permitted

How to reproduce

Calling BEGIN inside a PL/pgSQL function.

trigger — this will ERROR

CREATE OR REPLACE FUNCTION bad_begin() RETURNS VOID AS $
BEGIN
  BEGIN; -- invalid: already inside a transaction
END;
$ LANGUAGE plpgsql;

ERROR: cannot begin/end transactions in PL/pgSQL

Fix 1: Use SAVEPOINTs instead of nested BEGIN

When you need nested transaction semantics inside a function.

fix

SAVEPOINT my_save;
-- ... work ...
ROLLBACK TO SAVEPOINT my_save;
RELEASE SAVEPOINT my_save;

Why this works

SAVEPOINTs provide rollback-to-point semantics within the enclosing transaction without requiring a new BEGIN.

Fix 2: Use procedures with autonomous transaction control (Postgres 11+)

When the function genuinely needs to commit work independently.

fix

CREATE PROCEDURE my_proc() LANGUAGE plpgsql AS $
BEGIN
  -- work ...
  COMMIT;
END $;

Why this works

Procedures (not functions) can call COMMIT and ROLLBACK in Postgres 11+.

Version notes

Postgres 11+Procedures can use COMMIT/ROLLBACK. Functions still cannot.

Sources

📚 Official docs: https://www.postgresql.org/docs/current/errcodes-appendix.html

🔧 Source ref: Class 0B — Invalid Transaction Initiation

Confidence assessment

✅ HIGH confidence

Standard SQLSTATE. The function/procedure distinction for transaction control is stable and well-documented.