JanKaul commented on code in PR #11041: URL: https://github.com/apache/iceberg/pull/11041#discussion_r1851820348
########## format/view-spec.md: ########## @@ -42,12 +42,25 @@ An atomic swap of one view metadata file for another provides the basis for maki Writers create view metadata files optimistically, assuming that the current metadata location will not be changed before the writer's commit. Once a writer has created an update, it commits by swapping the view's metadata file pointer from the base location to the new location. +### Materialized Views + +Views have the option to be turned into materialized views by precomputing the data from the view query. +When queried, materialized views return the precomputed data, shifting the cost of query execution to the precomputation step. + +Iceberg materialized views are implemented as a combination of an Iceberg view and an underlying Iceberg table, known as the storage table, which stores the precomputed data. +The metadata for a materialized view extends the common view metadata, adding a pointer to the precomputed data and freshness information to determine if the data is still fresh. Review Comment: I think it's import to provide a little context about how Materialized Views are realized. I think it's much harder to understand the additional properties if the overall structure isn't clear. For example, I think it's very important to state that it is a combination of a view and a storage table. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
