feat(bigquery): add BIGNUMERIC type support

Author: krzysztof-kwitt

ibis/backends/bigquery/datatypes.py

@@ -66,12 +66,15 @@ def trans_type(t):
 
 @ibis_type_to_bigquery_type.register(dt.Decimal)
 def trans_numeric(t):
-    if (t.precision, t.scale) not in [(38, 9), (None, None)]:
-        raise TypeError(
-            "BigQuery only supports decimal types with precision of 38 and "
-            "scale of 9"
-        )
-    return "NUMERIC"
+    if (t.precision, t.scale) == (76, 38):
+        return 'BIGNUMERIC'
+    if (t.precision, t.scale) in [(38, 9), (None, None)]:
+        return "NUMERIC"
+    raise TypeError(
+        "BigQuery only supports decimal types with precision of 38 and "
+        f"scale of 9 (NUMERIC) or precision of 76 and scale of 38 (BIGNUMERIC). "
+        f"Current precision: {t.precision}. Current scale: {t.scale}"
+    )
 
 
 @ibis_type_to_bigquery_type.register(dt.JSON)

ibis/backends/bigquery/tests/unit/test_datatypes.py

@@ -49,7 +49,8 @@ def test_no_ambiguities():
         param(
             "array<struct<a: string>>", "ARRAY<STRUCT<a STRING>>", id="array<struct>"
         ),
-        param(dt.Decimal(38, 9), "NUMERIC", id="decimal"),
+        param(dt.Decimal(38, 9), "NUMERIC", id="decimal-numeric"),
+        param(dt.Decimal(76, 38), "BIGNUMERIC", id="decimal-bignumeric"),
     ],
 )
 def test_simple(datatype, expected):

ibis/backends/tests/test_generic.py

@@ -1374,6 +1374,40 @@ def test_exists(batting, awards_players, method_name):
             ],
             id="decimal-big",
         ),
+        param(
+            ibis.literal(decimal.Decimal("1.1"), type=dt.Decimal(76, 38)),
+            {
+                'bigquery': "BIGNUMERIC",
+                'snowflake': "VARCHAR",
+                'sqlite': "real",
+                'trino': 'decimal(2,1)',
+                "duckdb": "DECIMAL(18,3)",
+                "postgres": "numeric",
+            },
+            marks=[
+                pytest.mark.broken(
+                    ['clickhouse'],
+                    "Code: 46. DB::Exception: Unknown function Decimal: "
+                    "While processing toTypeName(Decimal('1.2')).",
+                    raises=ClickhouseDriverOperationalError,
+                ),
+                pytest.mark.broken(
+                    ['impala'],
+                    "impala.error.HiveServer2Error: AnalysisException: Syntax error in line 1:"
+                    "SELECT typeof(Decimal('1.2')) AS `TypeOf(Decimal('1.2'))"
+                    "Encountered: DECIMAL"
+                    "Expected: ALL, CASE, CAST, DEFAULT, DISTINCT, EXISTS, FALSE, IF, "
+                    "INTERVAL, LEFT, NOT, NULL, REPLACE, RIGHT, TRUNCATE, TRUE, IDENTIFIER"
+                    "CAUSED BY: Exception: Syntax error",
+                ),
+                pytest.mark.broken(
+                    ['duckdb'],
+                    "(duckdb.ParserException) Parser Error: Width must be between 1 and 38!",
+                    raises=sqlalchemy.exc.ProgrammingError,
+                ),
+            ],
+            id="decimal-big",
+        ),
         param(
             ibis.array([1.0, 2.0, 3.0]),
             {