[SPARK-3500] [SQL] use JavaSchemaRDD as SchemaRDD._jschema_rdd

Currently, SchemaRDD._jschema_rdd is SchemaRDD, the Scala API (coalesce(), repartition()) can not been called in Python easily, there is no way to specify the implicit parameter `ord`. The _jrdd is an JavaRDD, so _jschema_rdd should also be JavaSchemaRDD.

In this patch, change _schema_rdd to JavaSchemaRDD, also added an assert for it. If some methods are missing from JavaSchemaRDD, then it's called by _schema_rdd.baseSchemaRDD().xxx().

BTW, Do we need JavaSQLContext?

Author: Davies Liu <davies.liu@gmail.com>

Closes #2369 from davies/fix_schemardd and squashes the following commits:

abee159 [Davies Liu] use JavaSchemaRDD as SchemaRDD._jschema_rdd
This commit is contained in:
Davies Liu 2014-09-12 19:05:39 -07:00 committed by Josh Rosen
parent 71af030b46
commit 885d1621bc
2 changed files with 46 additions and 20 deletions

View file

@ -1122,7 +1122,7 @@ class SQLContext(object):
batched = isinstance(rdd._jrdd_deserializer, BatchedSerializer)
jrdd = self._pythonToJava(rdd._jrdd, batched)
srdd = self._ssql_ctx.applySchemaToPythonRDD(jrdd.rdd(), str(schema))
return SchemaRDD(srdd, self)
return SchemaRDD(srdd.toJavaSchemaRDD(), self)
def registerRDDAsTable(self, rdd, tableName):
"""Registers the given RDD as a temporary table in the catalog.
@ -1134,8 +1134,8 @@ class SQLContext(object):
>>> sqlCtx.registerRDDAsTable(srdd, "table1")
"""
if (rdd.__class__ is SchemaRDD):
jschema_rdd = rdd._jschema_rdd
self._ssql_ctx.registerRDDAsTable(jschema_rdd, tableName)
srdd = rdd._jschema_rdd.baseSchemaRDD()
self._ssql_ctx.registerRDDAsTable(srdd, tableName)
else:
raise ValueError("Can only register SchemaRDD as table")
@ -1151,7 +1151,7 @@ class SQLContext(object):
>>> sorted(srdd.collect()) == sorted(srdd2.collect())
True
"""
jschema_rdd = self._ssql_ctx.parquetFile(path)
jschema_rdd = self._ssql_ctx.parquetFile(path).toJavaSchemaRDD()
return SchemaRDD(jschema_rdd, self)
def jsonFile(self, path, schema=None):
@ -1207,11 +1207,11 @@ class SQLContext(object):
[Row(f1=u'row1', f2=None, f3=None)...Row(f1=u'row3', f2=[], f3=None)]
"""
if schema is None:
jschema_rdd = self._ssql_ctx.jsonFile(path)
srdd = self._ssql_ctx.jsonFile(path)
else:
scala_datatype = self._ssql_ctx.parseDataType(str(schema))
jschema_rdd = self._ssql_ctx.jsonFile(path, scala_datatype)
return SchemaRDD(jschema_rdd, self)
srdd = self._ssql_ctx.jsonFile(path, scala_datatype)
return SchemaRDD(srdd.toJavaSchemaRDD(), self)
def jsonRDD(self, rdd, schema=None):
"""Loads an RDD storing one JSON object per string as a L{SchemaRDD}.
@ -1275,11 +1275,11 @@ class SQLContext(object):
keyed._bypass_serializer = True
jrdd = keyed._jrdd.map(self._jvm.BytesToString())
if schema is None:
jschema_rdd = self._ssql_ctx.jsonRDD(jrdd.rdd())
srdd = self._ssql_ctx.jsonRDD(jrdd.rdd())
else:
scala_datatype = self._ssql_ctx.parseDataType(str(schema))
jschema_rdd = self._ssql_ctx.jsonRDD(jrdd.rdd(), scala_datatype)
return SchemaRDD(jschema_rdd, self)
srdd = self._ssql_ctx.jsonRDD(jrdd.rdd(), scala_datatype)
return SchemaRDD(srdd.toJavaSchemaRDD(), self)
def sql(self, sqlQuery):
"""Return a L{SchemaRDD} representing the result of the given query.
@ -1290,7 +1290,7 @@ class SQLContext(object):
>>> srdd2.collect()
[Row(f1=1, f2=u'row1'), Row(f1=2, f2=u'row2'), Row(f1=3, f2=u'row3')]
"""
return SchemaRDD(self._ssql_ctx.sql(sqlQuery), self)
return SchemaRDD(self._ssql_ctx.sql(sqlQuery).toJavaSchemaRDD(), self)
def table(self, tableName):
"""Returns the specified table as a L{SchemaRDD}.
@ -1301,7 +1301,7 @@ class SQLContext(object):
>>> sorted(srdd.collect()) == sorted(srdd2.collect())
True
"""
return SchemaRDD(self._ssql_ctx.table(tableName), self)
return SchemaRDD(self._ssql_ctx.table(tableName).toJavaSchemaRDD(), self)
def cacheTable(self, tableName):
"""Caches the specified table in-memory."""
@ -1353,7 +1353,7 @@ class HiveContext(SQLContext):
warnings.warn("hiveql() is deprecated as the sql function now parses using HiveQL by" +
"default. The SQL dialect for parsing can be set using 'spark.sql.dialect'",
DeprecationWarning)
return SchemaRDD(self._ssql_ctx.hiveql(hqlQuery), self)
return SchemaRDD(self._ssql_ctx.hiveql(hqlQuery).toJavaSchemaRDD(), self)
def hql(self, hqlQuery):
"""
@ -1524,6 +1524,8 @@ class SchemaRDD(RDD):
def __init__(self, jschema_rdd, sql_ctx):
self.sql_ctx = sql_ctx
self._sc = sql_ctx._sc
clsName = jschema_rdd.getClass().getName()
assert clsName.endswith("JavaSchemaRDD"), "jschema_rdd must be JavaSchemaRDD"
self._jschema_rdd = jschema_rdd
self._id = None
self.is_cached = False
@ -1540,7 +1542,7 @@ class SchemaRDD(RDD):
L{pyspark.rdd.RDD} super class (map, filter, etc.).
"""
if not hasattr(self, '_lazy_jrdd'):
self._lazy_jrdd = self._jschema_rdd.javaToPython()
self._lazy_jrdd = self._jschema_rdd.baseSchemaRDD().javaToPython()
return self._lazy_jrdd
def id(self):
@ -1598,7 +1600,7 @@ class SchemaRDD(RDD):
def schema(self):
"""Returns the schema of this SchemaRDD (represented by
a L{StructType})."""
return _parse_datatype_string(self._jschema_rdd.schema().toString())
return _parse_datatype_string(self._jschema_rdd.baseSchemaRDD().schema().toString())
def schemaString(self):
"""Returns the output schema in the tree format."""
@ -1649,8 +1651,6 @@ class SchemaRDD(RDD):
rdd = RDD(self._jrdd, self._sc, self._jrdd_deserializer)
schema = self.schema()
import pickle
pickle.loads(pickle.dumps(schema))
def applySchema(_, it):
cls = _create_cls(schema)
@ -1687,10 +1687,8 @@ class SchemaRDD(RDD):
def getCheckpointFile(self):
checkpointFile = self._jschema_rdd.getCheckpointFile()
if checkpointFile.isDefined():
if checkpointFile.isPresent():
return checkpointFile.get()
else:
return None
def coalesce(self, numPartitions, shuffle=False):
rdd = self._jschema_rdd.coalesce(numPartitions, shuffle)

View file

@ -607,6 +607,34 @@ class TestSQL(PySparkTestCase):
[res] = self.sqlCtx.sql("SELECT MYUDF('')").collect()
self.assertEqual("", res[0])
def test_basic_functions(self):
rdd = self.sc.parallelize(['{"foo":"bar"}', '{"foo":"baz"}'])
srdd = self.sqlCtx.jsonRDD(rdd)
srdd.count()
srdd.collect()
srdd.schemaString()
srdd.schema()
# cache and checkpoint
self.assertFalse(srdd.is_cached)
srdd.persist()
srdd.unpersist()
srdd.cache()
self.assertTrue(srdd.is_cached)
self.assertFalse(srdd.isCheckpointed())
self.assertEqual(None, srdd.getCheckpointFile())
srdd = srdd.coalesce(2, True)
srdd = srdd.repartition(3)
srdd = srdd.distinct()
srdd.intersection(srdd)
self.assertEqual(2, srdd.count())
srdd.registerTempTable("temp")
srdd = self.sqlCtx.sql("select foo from temp")
srdd.count()
srdd.collect()
class TestIO(PySparkTestCase):