Struct StreamScanNode 

pub struct StreamScanNode {
    pub table_id: u32,
    pub upstream_column_ids: Vec<i32>,
    pub output_indices: Vec<u32>,
    pub stream_scan_type: i32,
    pub state_table: Option<Table>,
    pub table_desc: Option<StorageTableDesc>,
    pub rate_limit: Option<u32>,
    pub snapshot_read_barrier_interval: u32,
    pub arrangement_table: Option<Table>,
    pub snapshot_backfill_epoch: Option<u64>,
}

StreamScanNode reads data from upstream table first, and then pass all events to downstream. It always these 2 inputs in the following order:

1. A MergeNode (as a placeholder) of upstream.
2. A BatchPlanNode for the snapshot read.

Fields

table_id: u32

upstream_column_ids: Vec<i32>

The columns from the upstream table that’ll be internally required by this stream scan node.

• For non-backfill stream scan node, it’s the same as the output columns.
• For backfill stream scan node, there’re additionally primary key columns.

output_indices: Vec<u32>

The columns to be output by this stream scan node. The index is based on the internal required columns.

• For non-backfill stream scan node, it’s simply all the columns.
• For backfill stream scan node, this strips the primary key columns if they’re unnecessary.

stream_scan_type: i32

Generally, the barrier needs to be rearranged during the MV creation process, so that data can be flushed to shared buffer periodically, instead of making the first epoch from batch query extra large. However, in some cases, e.g., shared state, the barrier cannot be rearranged in StreamScanNode. StreamScanType is used to decide which implementation for the StreamScanNode.

state_table: Option<Table>

/ The state table used by Backfill operator for persisting internal state

table_desc: Option<StorageTableDesc>

The upstream materialized view info used by backfill. Used iff ChainType::Backfill.

rate_limit: Option<u32>

The backfill rate limit for the stream scan node.

snapshot_read_barrier_interval: u32

👎Deprecated

Snapshot read every N barriers

arrangement_table: Option<Table>

The state table used by ArrangementBackfill to replicate upstream mview’s state table. Used iff ChainType::ArrangementBackfill.

snapshot_backfill_epoch: Option<u64>

Implementations

impl StreamScanNode

pub fn stream_scan_type(&self) -> StreamScanType

Returns the enum value of stream_scan_type, or the default if the field is set to an invalid enum value.

pub fn set_stream_scan_type(&mut self, value: StreamScanType)

Sets stream_scan_type to the provided enum value.

pub fn rate_limit(&self) -> u32

Returns the value of rate_limit, or the default value if rate_limit is unset.

pub fn snapshot_backfill_epoch(&self) -> u64

Returns the value of snapshot_backfill_epoch, or the default value if snapshot_backfill_epoch is unset.

impl StreamScanNode

pub fn get_table_id(&self) -> u32

pub fn get_upstream_column_ids(&self) -> &Vec<i32>

pub fn get_output_indices(&self) -> &Vec<u32>

pub fn get_stream_scan_type(&self) -> Result<StreamScanType, PbFieldNotFound>

pub fn get_state_table(&self) -> Result<&Table, PbFieldNotFound>

pub fn get_table_desc(&self) -> Result<&StorageTableDesc, PbFieldNotFound>

pub fn get_rate_limit(&self) -> Result<&u32, PbFieldNotFound>

pub fn get_snapshot_read_barrier_interval(&self) -> u32

👎Deprecated

pub fn get_arrangement_table(&self) -> Result<&Table, PbFieldNotFound>

pub fn get_snapshot_backfill_epoch(&self) -> Result<&u64, PbFieldNotFound>

impl StreamScanNode

pub fn upstream_columns(&self) -> Vec<PbColumnDesc>

See Self::upstream_column_ids.

Trait Implementations

impl Clone for StreamScanNode

fn clone(&self) -> StreamScanNode

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StreamScanNode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for StreamScanNode

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for StreamScanNode

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Message for StreamScanNode

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for StreamScanNode

fn eq(&self, other: &StreamScanNode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for StreamScanNode

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for StreamScanNode