public MaterializedViewMetadata reset(MaterializationSnapshot snapshot) {
    Set<SourceTable> newSourceTables =
            creationMetadata.getSourceTables().stream().map(this::from).collect(Collectors.toSet());

    return new MaterializedViewMetadata(
            creationMetadata.getCatName(),
            creationMetadata.getDbName(),
            creationMetadata.getTblName(),
            unmodifiableSet(newSourceTables),
            snapshot);
  }
Get the snapshot data of the materialized view source tables stored in HMS.
The returned object contains the valid txn list in case of native acid tables
or the snapshotIds of tables which storage handle supports snapshots.
@return {@link MaterializationSnapshot} object or null if the wrapped {@link CreationMetadata} object
does not contain snapshot data
ql/src/java/org/apache/hadoop/hive/ql/metadata/MaterializedViewMetadata.java