Problem

In a Unity Catalog-enabled workspace, you run the following SQL command in a notebook to apply a SKEW join hint on a table.

%sql
SELECT /*+ SKEW('<table-name>', '<column-name>', (0, 1)) */ 
  <column1>, 
 <column2>
FROM <catalog>.<schema>.<table-name>;

The query fails with the following error.

Skew hint: invalid arguments List(<table-name>, <column-name>, named_struct(col1, 0, col2, 1))

Cause

In Unity Catalog-enabled workspaces, the SKEW hint requires the fully qualified table name, <catalog>.<schema>.<table-name>. 

Providing only the table name is not sufficient. The parser interprets the arguments incorrectly and returns the "invalid arguments" error.

Solution

Rewrite the query using the fully-qualified Unity Catalog name. The following code rewrites the example from the problem statement to demonstrate. 

%sql
SELECT /*+ SKEW('<catalog>.<schema>.<table-name>', '<column-name>', (0, 1)) */ 
  <column1>, 
  <column2>
FROM <catalog>.<schema>.<table-name>;