Method delete

nodedb-columnar/src/mutation/write.rs:169–195

Delete a row by PK value. Returns WAL record to persist. Looks up PK in the index to find the segment + row, then marks the row in the segment's delete bitmap.

(&mut self, pk_value: &Value)

    /// Looks up PK in the index to find the segment + row, then marks
    /// the row in the segment's delete bitmap.
    pub fn delete(&mut self, pk_value: &Value) -> Result<MutationResult, ColumnarError> {
        let pk_bytes = encode_pk(pk_value);

        let location = self
            .pk_index
            .get(&pk_bytes)
            .copied()
            .ok_or(ColumnarError::PrimaryKeyNotFound)?;

        // Generate WAL record BEFORE applying.
        let wal = ColumnarWalRecord::DeleteRows {
            collection: self.collection.clone(),
            segment_id: location.segment_id,
            row_indices: vec![location.row_index],
        };

        // Mark in delete bitmap.
        let bitmap = self.delete_bitmaps.entry(location.segment_id).or_default();
        bitmap.mark_deleted(location.row_index);

        // Remove from PK index.
        self.pk_index.remove(&pk_bytes);

        Ok(MutationResult {
            wal_records: vec![wal],
        })
    }

    /// Update a row by PK: DELETE old + INSERT new.
    ///