mz_adapter::catalog::open::builtin_schema_migration

Function read_migration_shard

Source 
async fn read_migration_shard<P>(
    persist_read: &mut ReadHandle<Key, ShardId, Timestamp, StorageDiff>,
    read_ts: Timestamp,
    predicate: P,
) -> Option<Vec<(Key, ShardId)>>
where
    P: for<'a> Fn(&Key) -> bool,
Expand description

Read the migration shard at the given timestamp, returning all entries that match the given predicate.

Returns None if the migration shard contains no matching entries, or if it isn’t readable at read_ts.