jackc/pgx · error

%d unexpected trailing bytes at offset %d

Error message

%d unexpected trailing bytes at offset %d

What it means

Error "%d unexpected trailing bytes at offset %d" thrown in jackc/pgx.

Source

Thrown at internal/pgio/read.go:208

		return nil, false
	}
	return r.Bytes(int(length)), false
}

// Finish returns the first error encountered, or an error if unread bytes
// remain. Decoders that must consume the entire source should end with Finish.
func (r *Reader) Finish() error {
	if r.err != nil {
		return r.err
	}
	if r.rp != len(r.s) {
		return r.errTrailing()
	}
	return nil
}

func (r *Reader) errTrailing() error {
	return fmt.Errorf("%d unexpected trailing bytes at offset %d", len(r.s)-r.rp, r.rp)
}

// ErrInvalidLength is wrapped by the errors returned from the exact-length
// read functions below.
var ErrInvalidLength = errors.New("invalid length")

func errLength(want, got int) error {
	return fmt.Errorf("%w: expected %d bytes, got %d", ErrInvalidLength, want, got)
}

// The Uint*Exact functions read a single fixed-size value that makes up an
// entire message, which is what the scan plans for the fixed-size PostgreSQL
// types receive. They are the counterpart to Reader for values that have no
// internal structure: there is no position to track and no error to make
// sticky, just an exact-length assertion the caller cannot skip. Keeping them
// separate from Reader is deliberate — these are the hottest decode paths in
// the driver and they are small enough for the compiler to inline, which a
// Reader method carrying a bounds check and a read pointer is not.

View on GitHub (pinned to ec1a0befd2)

When it happens

Trigger: Thrown at internal/pgio/read.go:208 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /data/errors/21e71eff5b030dcb.json. Report an issue: GitHub.