risingwave_storage::store

Trait StateStoreWrite

source 
pub trait StateStoreWrite: StaticSendSync {
    // Required method
    fn ingest_batch(
        &self,
        kv_pairs: Vec<(TableKey<Bytes>, StorageValue)>,
        delete_ranges: Vec<(Bound<Bytes>, Bound<Bytes>)>,
        write_options: WriteOptions,
    ) -> StorageResult<usize>;
}

Required Methods§

source

fn ingest_batch( &self, kv_pairs: Vec<(TableKey<Bytes>, StorageValue)>, delete_ranges: Vec<(Bound<Bytes>, Bound<Bytes>)>, write_options: WriteOptions, ) -> StorageResult<usize>

Writes a batch to storage. The batch should be:

  • Ordered. KV pairs will be directly written to the table, so it must be ordered.
  • Locally unique. There should not be two or more operations on the same key in one write batch.

Ingests a batch of data into the state store. One write batch should never contain operation on the same key. e.g. Put(233, x) then Delete(233). An epoch should be provided to ingest a write batch. It is served as:

  • A handle to represent an atomic write session. All ingested write batches associated with the same Epoch have the all-or-nothing semantics, meaning that partial changes are not queryable and will be rolled back if instructed.
  • A version of a kv pair. kv pair associated with larger Epoch is guaranteed to be newer then kv pair with smaller Epoch. Currently this version is only used to derive the per-key modification history (e.g. in compaction), not across different keys.

Implementors§