feat(trino): implement Table.sample as a TABLESAMPLE query

ibis/backends/tests/test_generic.py

@@ -1541,7 +1541,6 @@ def test_dynamic_table_slice_with_computed_offset(backend):
         "polars",
         "pyspark",
         "snowflake",
-        "trino",
     ]
 )
 def test_sample(backend):
@@ -1571,7 +1570,6 @@ def test_sample(backend):
         "polars",
         "pyspark",
         "snowflake",
-        "trino",
     ]
 )
 def test_sample_memtable(con, backend):

ibis/backends/trino/compiler.py

@@ -7,6 +7,7 @@
 from ibis.backends.base.sql.alchemy.query_builder import _AlchemyTableSetFormatter
 from ibis.backends.trino.datatypes import TrinoType
 from ibis.backends.trino.registry import operation_registry
+from ibis.common.exceptions import UnsupportedOperationError
 
 
 class TrinoSQLExprTranslator(AlchemyExprTranslator):
@@ -47,6 +48,16 @@ def _rewrite_string_contains(op):
 
 
 class TrinoTableSetFormatter(_AlchemyTableSetFormatter):
+    def _format_sample(self, op, table):
+        if op.seed is not None:
+            raise UnsupportedOperationError(
+                "`Table.sample` with a random seed is unsupported"
+            )
+        method = sa.func.bernoulli if op.method == "row" else sa.func.system
+        return table.tablesample(
+            sampling=method(sa.literal_column(f"{op.fraction * 100}"))
+        )
+
     def _format_in_memory_table(self, op, translator):
         if not op.data:
             return sa.select(
@@ -65,7 +76,7 @@ def _format_in_memory_table(self, op, translator):
             for row in op.data.to_frame().itertuples(index=False)
         ]
         columns = translator._schema_to_sqlalchemy_columns(op.schema)
-        return sa.values(*columns, name=op.name).data(rows)
+        return sa.values(*columns, name=op.name).data(rows).select().subquery()
 
 
 class TrinoSQLCompiler(AlchemyCompiler):