Major Description
SELECT * FROM testData TABLESAMPLE (-1 rows) SELECT * FROM testData LIMIT -1
Negative values should not be allowed in TABLESAMPLE n ROWS and LIMIT n
In addition, Spark SQL follows the restriction of LIMIT clause in Hive. The argument to the LIMIT clause must evaluate to a constant value. It can be a numeric literal, or another kind of numeric expression involving operators, casts, and function return values. You cannot refer to a column or use a subquery. Currently, we do not detect whether the expression in LIMIT clause is foldable or not. If non-foldable, we might issue a strange error message. For example,
SELECT * FROM testData LIMIT rand() > 0.2
Then, a misleading error message is issued, like
assertion failed: No plan for GlobalLimit (_nondeterministic#203 > 0.2)
+- Project [key#11, value#12, rand(-1441968339187861415) AS _nondeterministic#203]
+- LocalLimit (_nondeterministic#202 > 0.2)
+- Project [key#11, value#12, rand(-1308350387169017676) AS _nondeterministic#202]
+- LogicalRDD [key#11, value#12]
java.lang.AssertionError: assertion failed: No plan for GlobalLimit (_nondeterministic#203 > 0.2)
+- Project [key#11, value#12, rand(-1441968339187861415) AS _nondeterministic#203]
+- LocalLimit (_nondeterministic#202 > 0.2)
+- Project [key#11, value#12, rand(-1308350387169017676) AS _nondeterministic#202]
+- LogicalRDD [key#11, value#12]
