paul-rogers commented on issue #12546: URL: https://github.com/apache/druid/issues/12546#issuecomment-1144196772
@clintropolis, thanks for the note on `INFORMATION_SCHEMA` It appears that it was introduced in [SQL 92](https://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt), and appears to have a very 1980's feel to it in naming and types. Various DBs support varying aspects of the schema. A quick scan of the table-of-contents of the [SQL 2016 spec](https://blog.ansi.org/2018/10/sql-standard-iso-iec-9075-2016-ansi-x3-135) suggests that the information schema still exists, though I'd have to buy the spec to find out how much it has evolved since SQL-92. [MySQL](https://dev.mysql.com/doc/refman/8.0/en/information-schema-table-reference.html) for example adds many, many tables on top of the standard SQL-92 set. The key fact is that `INFORMATION_SCHEMA` is intended to be a set of views on top of the underlying "definition tables." There are no definition tables in Druid: information is stored in non-table form in multiple places. The proposed catalog adds to those sources of information. Druid's `INFORMATION_SCHEMA`simulates the views by creating table contents on the fly. This aspect will remain unchanged in this proposal. Updated the `INFORMATION_SCHEMA` section to reflect this information. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
