presto-parquet/src/main/java/io/prestosql/parquet/predicate/PredicateUtils.java/PredicateUtils/isOnlyDictionaryEncodingPages
class PredicateUtils:    @VisibleForTesting
    @SuppressWarnings("deprecation")
    static boolean isOnlyDictionaryEncodingPages(ColumnChunkMetaData columnMetaData)
    {
        // Files written with newer versions of Parquet libraries (e.g. parquet-mr 1.9.0) will have EncodingStats available
        // Otherwise, fallback to v1 logic
        EncodingStats stats = columnMetaData.getEncodingStats();
        if (stats != null) {
            return stats.hasDictionaryPages() && !stats.hasNonDictionaryEncodedPages();
        }

        Set<Encoding> encodings = columnMetaData.getEncodings();
        if (encodings.contains(PLAIN_DICTIONARY)) {
            // PLAIN_DICTIONARY was present, which means at least one page was
            // dictionary-encoded and 1.0 encodings are used
            // The only other allowed encodings are RLE and BIT_PACKED which are used for repetition or definition levels
            return Sets.difference(encodings, ImmutableSet.of(PLAIN_DICTIONARY, RLE, BIT_PACKED)).isEmpty();
        }

        return false;
    }