emkornfield commented on code in PR #197:
URL: https://github.com/apache/parquet-format/pull/197#discussion_r1313391714
##########
src/main/thrift/parquet.thrift:
##########
@@ -191,6 +191,74 @@ enum FieldRepetitionType {
REPEATED = 2;
}
+/**
+ * A histogram of repetition and definition levels for either a page or column
+ * chunk.
+ *
+ * This is useful for:
+ * 1. Estimating the size of the data when materialized in
+ * memory
+ *
+ * 2. For filter push-down on nulls at various levels of nested
+ * structures and list lengths.
+ */
+struct RepetitionDefinitionLevelHistogram {
+ /**
+ * When present, there is expected to be one element corresponding to each
+ * repetition (i.e. size=max repetition_level+1) where each element
+ * represents the number of times the repetition level was observed in the
+ * data.
+ *
+ * This value should not be written if max_repetition_level is 0.
+ **/
+ 1: optional list<i64> repetition_level_histogram;
+ /**
+ * Same as repetition_level_histogram except for definition levels.
+ *
+ * This value should not be written if max_definition_level is 0 or 1.
Review Comment:
I tend to agree. I might be misunderstanding here but @gszadovszky seems to
have concerns around this area?
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: dev-unsubscr...@parquet.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
