Dropping a MATERIALIZED VIEW fails in the latest versions.

[rstyp]

If a MATERIALIZED VIEW was previously created with a storage table, and the latest version has enabled iceberg.materialized-views.hide-storage-table, attempting to DROP the MATERIALIZED VIEW will result in the following error:

java.lang.IllegalStateException: Storage location missing in definition of materialized view sample_mv
    at com.google.common.base.Preconditions.checkState(Preconditions.java:512)
    at io.trino.plugin.iceberg.catalog.hms.TrinoHiveCatalog.dropMaterializedView(TrinoHiveCatalog.java:731)
    at io.trino.plugin.iceberg.IcebergMetadata.dropMaterializedView(IcebergMetadata.java:2855)
    at io.trino.plugin.base.classloader.ClassLoaderSafeConnectorMetadata.dropMaterializedView(ClassLoaderSafeConnectorMetadata.java:1125)
    at io.trino.tracing.TracingConnectorMetadata.dropMaterializedView(TracingConnectorMetadata.java:1283)
    at io.trino.metadata.MetadataManager.dropMaterializedView(MetadataManager.java:1579)

I think this block of code should be relocated to the else block.

trino/plugin/trino-iceberg/src/main/java/io/trino/plugin/iceberg/catalog/hms/TrinoHiveCatalog.java

Lines 730 to 741 in bc85d90

	String storageMetadataLocation = view.getParameters().get(METADATA_LOCATION_PROP);
	checkState(storageMetadataLocation != null, "Storage location missing in definition of materialized view " + viewName);
	TrinoFileSystem fileSystem = fileSystemFactory.create(session);
	TableMetadata metadata = TableMetadataParser.read(new ForwardingFileIo(fileSystem), storageMetadataLocation);
	String storageLocation = metadata.location();
	try {
	fileSystem.deleteDirectory(Location.of(storageLocation));
	}
	catch (IOException e) {
	log.warn(e, "Failed to delete storage location '%s' for materialized view '%s'", storageLocation, viewName);
	}

[hashhar]

cc: @alexjo2144

[rstyp]

Thanks @hashhar,@alexjo2144, will send the parch PR soon.

[alexjo2144]

Hey @rstyp , thanks for reporting,

I think this block of code should be relocated to the else block.

I think that's the fix as well.

@rstyp would you like to put up a fix or should I?

[alexjo2144]

@rstyp I found some other problems in this code today as well. Not as bad as this one, but enough that I've put up a PR with the patch you suggested above and a fix for what I found: #20892