risingwavelabs/risingwave · error

Invalid row count state: {:?}

Error message

Invalid row count state: {:?}

What it means

`decode_row_count` reads the persisted row-count state of an approx_percentile aggregator and expects the single state row to carry an Int64 datum at position 0. If the row exists but has a NULL first datum, the state is malformed and this error is raised.

Source

Thrown at src/stream/src/executor/approx_percentile/global_state.rs:123

                1 => {
                    self.cache.pos_buckets.insert(bucket_id, count as i64);
                }
                _ => {
                    bail!("Invalid sign: {}", sign);
                }
            }
        }
        Ok(())
    }

    async fn get_row_count_state(&self) -> StreamExecutorResult<Option<OwnedRow>> {
        self.count_state_table.get_row(&[Datum::None; 0]).await
    }

    fn decode_row_count(row_count_state: &Option<OwnedRow>) -> StreamExecutorResult<i64> {
        if let Some(row) = row_count_state.as_ref() {
            let Some(datum) = row.datum_at(0) else {
                bail!("Invalid row count state: {:?}", row)
            };
            Ok(datum.into_int64())
        } else {
            Ok(0)
        }
    }
}

// Update
impl<S: StateStore> GlobalApproxPercentileState<S> {
    pub fn apply_chunk(&mut self, chunk: StreamChunk) -> StreamExecutorResult<()> {
        // Op is ignored here, because we only check the `delta` column inside the row.
        // The sign of the `delta` column will tell us if we need to decrease or increase the
        // count of the bucket.
        for (_op, row) in chunk.rows() {
            debug_assert_eq!(_op, Op::Insert);
            self.apply_row(row)?;
        }

View on GitHub (pinned to 6469eb736d)

Solutions

1. Drop and recreate the materialized view using approx_percentile to reset its state tables.
2. Verify the RW versions that wrote and read the state match; if an upgrade is involved, re-ingest the data instead of recovering state.
3. Inspect the state table for the actor via internal catalog/tools and confirm the row is NULL; if reproducible, report as a state-writer bug.
4. Fall back to restoring from a backup/snapshot of the state store taken when the data was valid.

When it happens

Trigger: Recovery/init of an approx_percentile global aggregator where the row-count state table contains a row whose only column is NULL — e.g. state written incompletely before a crash or by an incompatible writer version.

Common situations: Crash between inserting an empty row and filling it, RisingWave version upgrades changing state schema, or corrupted state store data.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Invalid sign: {}
• corrupt MATCH_RECOGNIZE state row: seq column must be a non-
• a stream has reached the end but some other stream has not s
• invalid state, new_count = 0 and is_new_entry is true
• invalid backfill state: row_count

AI-assisted analysis of risingwavelabs/risingwave@6469eb736d (2026-09-11). Data as JSON: /api/errors/7f42686f45db188c. Report an issue: GitHub.