cloud-fan commented on a change in pull request #26806: [SPARK-30183][SQL] Disallow to specify reserved properties in CREATE NAMESPACE syntax URL: https://github.com/apache/spark/pull/26806#discussion_r363626405
########## File path: docs/sql-migration-guide.md ########## @@ -264,6 +264,8 @@ license: | - Since Spark 3.0, the function `percentile_approx` and its alias `approx_percentile` only accept integral value with range in `[1, 2147483647]` as its 3rd argument `accuracy`, fractional and string types are disallowed, e.g. `percentile_approx(10.0, 0.2, 1.8D)` will cause `AnalysisException`. In Spark version 2.4 and earlier, if `accuracy` is fractional or string value, it will be coerced to an int value, `percentile_approx(10.0, 0.2, 1.8D)` is operated as `percentile_approx(10.0, 0.2, 1)` which results in `10.0`. + - Since Spark 3.0, the namespace properties `location` and `comment` become reserved, it will fail with `ParseException` if we use them as members of `DBPROTERTIES` in `CREATE NAMESPACE` and `ALTER NAMESPACE ... SET PROPERTIES(...)`. We need their specific clauses to specify them, e.g. `CREATE NAMESPACE a.b.c COMMENT 'any comment' LOCATION 'some path'`. We can set `spark.sql.legacy.property.nonReserved` to `true` to ignore the `ParseException`, but notice that in this case, these properties will produce side effects, e.g `SET DBPROTERTIES('location'='/tmp')` might change the location of the database. In Spark version 2.4 and earlier, these properties are neither reserved nor have side effects, e.g. `SET DBPROTERTIES('location'='/tmp')` will not change the location of the database but create a headless property just like `'a'='b'`. + Review comment: hey, we should ignore them (i.e. remove them from properties), so that they won't have side effect. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org