Parse information returned by list_relations_without_caching macro to speed up catalog generation

CHANGELOG.md

@@ -4,8 +4,14 @@
 
 - Cast `table_owner` to string to avoid errors generating docs ([#158](https://github.com/fishtown-analytics/dbt-spark/pull/158), [#159](https://github.com/fishtown-analytics/dbt-spark/pull/159))
 
+### Under the hood
+
+- Parse information returned by `list_relations_without_caching` macro to speed up catalog generation ([#93](https://github.com/fishtown-analytics/dbt-spark/issues/93), [#160](https://github.com/fishtown-analytics/dbt-spark/pull/160))
+
 ### Contributors
 - [@friendofasquid](https://github.com/friendofasquid) ([#159](https://github.com/fishtown-analytics/dbt-spark/pull/159))
+- [@franloza](https://github.com/franloza) ([#160](https://github.com/fishtown-analytics/dbt-spark/pull/160))
+
 
 ## dbt-spark 0.19.1 (Release TBD)
 

dbt/adapters/spark/impl.py

@@ -1,3 +1,4 @@
+import re
 from concurrent.futures import Future
 from dataclasses import dataclass
 from typing import Optional, List, Dict, Any, Union, Iterable
@@ -60,6 +61,9 @@ class SparkAdapter(SQLAdapter):
         'stats:rows:description',
         'stats:rows:include',
     )
+    INFORMATION_COLUMNS_REGEX = re.compile(
+        r"\|-- (.*): (.*) \(nullable = (.*)\b", re.MULTILINE)
+    INFORMATION_OWNER_REGEX = re.compile(r"^Owner: (.*)$", re.MULTILINE)
 
     Relation = SparkRelation
     Column = SparkColumn
@@ -139,7 +143,8 @@ def list_relations_without_caching(
                 schema=_schema,
                 identifier=name,
                 type=rel_type,
-                is_delta=is_delta
+                information=information,
+                is_delta=is_delta,
             )
             relations.append(relation)
 
@@ -197,19 +202,49 @@ def find_table_information_separator(rows: List[dict]) -> int:
         return pos
 
     def get_columns_in_relation(self, relation: Relation) -> List[SparkColumn]:
-        rows: List[agate.Row] = super().get_columns_in_relation(relation)
-        return self.parse_describe_extended(relation, rows)
+        cached_relations = self.cache.get_relations(
+            relation.database, relation.schema)
+        cached_relation = next((cached_relation
+                                for cached_relation in cached_relations
+                                if str(cached_relation) == str(relation)),
+                               None)
+        if cached_relation is None:
+            rows: List[agate.Row] = super().get_columns_in_relation(relation)
+            columns = self.parse_describe_extended(relation, rows)
+        else:
+            columns = self.parse_columns_from_information(cached_relation)
+        return columns
+
+    def parse_columns_from_information(
+            self, relation: SparkRelation
+    ) -> List[SparkColumn]:
+        owner_match = re.findall(
+            self.INFORMATION_OWNER_REGEX, relation.information)
+        owner = owner_match[0] if owner_match else None
+        matches = re.finditer(
+            self.INFORMATION_COLUMNS_REGEX, relation.information)
+        columns = []
+        for match_num, match in enumerate(matches):
+            column_name, column_type, nullable = match.groups()
+            column = SparkColumn(
+                table_database=None,
+                table_schema=relation.schema,
+                table_name=relation.table,
+                table_type=relation.type,
+                column_index=match_num,
+                table_owner=owner,
+                column=column_name,
+                dtype=column_type
+            )
+            columns.append(column)
+        return columns
 
     def _get_columns_for_catalog(
         self, relation: SparkRelation
     ) -> Iterable[Dict[str, Any]]:
-        properties = self.get_properties(relation)
-        columns = self.get_columns_in_relation(relation)
-        owner = properties.get(KEY_TABLE_OWNER)
+        columns = self.parse_columns_from_information(relation)
 
         for column in columns:
-            if owner:
-                column.table_owner = owner
             # convert SparkColumns into catalog dicts
             as_dict = column.to_column_dict()
             as_dict['column_name'] = as_dict.pop('column', None)

dbt/adapters/spark/relation.py

@@ -26,6 +26,7 @@ class SparkRelation(BaseRelation):
     include_policy: SparkIncludePolicy = SparkIncludePolicy()
     quote_character: str = '`'
     is_delta: Optional[bool] = None
+    information: str = None
 
     def __post_init__(self):
         if self.database != self.schema and self.database:

test/unit/test_adapter.py

@@ -446,3 +446,114 @@ def test_profile_with_cluster_and_sql_endpoint(self):
         }
         with self.assertRaises(RuntimeException):
             config_from_parts_or_dicts(self.project_cfg, profile)
+
+    def test_parse_columns_from_information_with_table_type(self):
+        self.maxDiff = None
+        rel_type = SparkRelation.get_relation_type.Table
+
+        # Mimics the output of Spark in the information column
+        information = (
+            "Database: default_schema\n"
+            "Table: mytable\n"
+            "Owner: root\n"
+            "Created Time: Wed Feb 04 18:15:00 UTC 1815\n"
+            "Last Access: Wed May 20 19:25:00 UTC 1925\n"
+            "Created By: Spark 3.0.1\n"
+            "Type: MANAGED\n"
+            "Provider: delta\n"
+            "Statistics: 123456789 bytes\n"
+            "Location: /mnt/vo\n"
+            "Serde Library: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe\n"
+            "InputFormat: org.apache.hadoop.mapred.SequenceFileInputFormat\n"
+            "OutputFormat: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat\n"
+            "Partition Provider: Catalog\n"
+            "Partition Columns: [`dt`]\n"
+            "Schema: root\n"
+            " |-- col1: decimal(22,0) (nullable = true)\n"
+            " |-- col2: string (nullable = true)\n"
+            " |-- dt: date (nullable = true)\n"
+        )
+        relation = SparkRelation.create(
+            schema='default_schema',
+            identifier='mytable',
+            type=rel_type,
+            information=information
+        )
+
+        config = self._get_target_http(self.project_cfg)
+        columns = SparkAdapter(config).parse_columns_from_information(
+            relation)
+        self.assertEqual(len(columns), 3)
+        self.assertEqual(columns[0].to_column_dict(omit_none=False), {
+            'table_database': None,
+            'table_schema': relation.schema,
+            'table_name': relation.name,
+            'table_type': rel_type,
+            'table_owner': 'root',
+            'column': 'col1',
+            'column_index': 0,
+            'dtype': 'decimal(22,0)',
+            'numeric_scale': None,
+            'numeric_precision': None,
+            'char_size': None
+        })
+
+    def test_parse_columns_from_information_with_view_type(self):
+        self.maxDiff = None
+        rel_type = SparkRelation.get_relation_type.View
+        information = (
+            "Database: default_schema\n"
+            "Table: myview\n"
+            "Owner: root\n"
+            "Created Time: Wed Feb 04 18:15:00 UTC 1815\n"
+            "Last Access: UNKNOWN\n"
+            "Created By: Spark 3.0.1\n"
+            "Type: VIEW\n"
+            "View Text: WITH base (\n"
+            "    SELECT * FROM source_table\n"
+            ")\n"
+            "SELECT col1, col2, dt FROM base\n"
+            "View Original Text: WITH base (\n"
+            "    SELECT * FROM source_table\n"
+            ")\n"
+            "SELECT col1, col2, dt FROM base\n"
+            "View Catalog and Namespace: spark_catalog.default\n"
+            "View Query Output Columns: [col1, col2, dt]\n"
+            "Table Properties: [view.query.out.col.1=col1, view.query.out.col.2=col2, "
+            "transient_lastDdlTime=1618324324, view.query.out.col.3=dt, "
+            "view.catalogAndNamespace.part.0=spark_catalog, "
+            "view.catalogAndNamespace.part.1=default]\n"
+            "Serde Library: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe\n"
+            "InputFormat: org.apache.hadoop.mapred.SequenceFileInputFormat\n"
+            "OutputFormat: org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat\n"
+            "Storage Properties: [serialization.format=1]\n"
+            "Schema: root\n"
+            " |-- col1: decimal(22,0) (nullable = true)\n"
+            " |-- col2: string (nullable = true)\n"
+            " |-- dt: date (nullable = true)\n"
+        )
+        relation = SparkRelation.create(
+            schema='default_schema',
+            identifier='myview',
+            type=rel_type,
+            information=information
+        )
+
+        config = self._get_target_http(self.project_cfg)
+        columns = SparkAdapter(config).parse_columns_from_information(
+            relation)
+        self.assertEqual(len(columns), 3)
+        self.assertEqual(columns[1].to_column_dict(omit_none=False), {
+            'table_database': None,
+            'table_schema': relation.schema,
+            'table_name': relation.name,
+            'table_type': rel_type,
+            'table_owner': 'root',
+            'column': 'col2',
+            'column_index': 1,
+            'dtype': 'string',
+            'numeric_scale': None,
+            'numeric_precision': None,
+            'char_size': None
+        })
+