roczei commented on PR #37679: URL: https://github.com/apache/spark/pull/37679#issuecomment-1250958346
> Is this a common behavior in other databases? @cloud-fan Good question. The reason that we cannot delete the user specified default database because we have the following if statement in the actual code: ``` if (dbName == defaultDatabase) ``` and this is the latest state of master: https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala#L286 ``` def dropDatabase(db: String, ignoreIfNotExists: Boolean, cascade: Boolean): Unit = { val dbName = format(db) if (dbName == DEFAULT_DATABASE) { throw QueryCompilationErrors.cannotDropDefaultDatabaseError } ``` As you can see that I am just using the same logic. If you think that we should only deny the database drop for "default" and allow for the value of spark.sql.catalog.spark_catalog.defaultDatabase, it is ok for me. The change is very simple: ``` +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala @@ -284,7 +284,7 @@ class SessionCatalog( def dropDatabase(db: String, ignoreIfNotExists: Boolean, cascade: Boolean): Unit = { val dbName = format(db) - if (dbName == defaultDatabase) { + if (dbName == "default") { throw QueryCompilationErrors.cannotDropDefaultDatabaseError } if (!ignoreIfNotExists) { ``` and here is the validation: ``` $ ./spark-shell --conf spark.sql.catalogImplementation=hive --conf spark.sql.catalog.spark_catalog.defaultDatabase=xyz Setting default log level to "WARN". To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel). 22/09/19 14:21:07 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Spark context Web UI available at http://localhost:4040 Spark context available as 'sc' (master = local[*], app id = local-1663590068068). Spark session available as 'spark'. Welcome to ____ __ / __/__ ___ _____/ /__ _\ \/ _ \/ _ `/ __/ '_/ /___/ .__/\_,_/_/ /_/\_\ version 3.4.0-SNAPSHOT /_/ Using Scala version 2.12.17 (OpenJDK 64-Bit Server VM, Java 1.8.0_345) Type in expressions to have them evaluated. Type :help for more information. scala> spark.sql("show databases").show() +---------+ |namespace| +---------+ | abc| | default| | xyz| +---------+ scala> spark.sql("use database abc") res1: org.apache.spark.sql.DataFrame = [] scala> spark.sql("SELECT current_database() AS db").show() +---+ | db| +---+ |abc| +---+ scala> scala> spark.sql("drop database xyz") res3: org.apache.spark.sql.DataFrame = [] scala> spark.sql("show databases").show() +---------+ |namespace| +---------+ | abc| | default| +---------+ scala> ``` Is this solution acceptable for you? -- 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]
