Add reflection of PostgreSQL index access methods (USING clause)pr/179

2 files changed, 32 insertions, 3 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index b9690e214..fa11956ad 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -2625,7 +2625,7 @@ class PGDialect(default.DefaultDialect):
                   i.relname as relname,
                   ix.indisunique, ix.indexprs, ix.indpred,
                   a.attname, a.attnum, NULL, ix.indkey%s,
-                  i.reloptions
+                  i.reloptions, am.amname
               FROM
                   pg_class t
                         join pg_index ix on t.oid = ix.indrelid
@@ -2633,6 +2633,9 @@ class PGDialect(default.DefaultDialect):
                         left outer join
                             pg_attribute a
                             on t.oid = a.attrelid and %s
+                        left outer join
+                            pg_am am
+                            on i.relam = am.oid
               WHERE
                   t.relkind IN ('r', 'v', 'f', 'm')
                   and t.oid = :table_oid
@@ -2653,7 +2656,7 @@ class PGDialect(default.DefaultDialect):
                   i.relname as relname,
                   ix.indisunique, ix.indexprs, ix.indpred,
                   a.attname, a.attnum, c.conrelid, ix.indkey::varchar,
-                  i.reloptions
+                  i.reloptions, am.amname
               FROM
                   pg_class t
                         join pg_index ix on t.oid = ix.indrelid
@@ -2666,6 +2669,9 @@ class PGDialect(default.DefaultDialect):
                             on (ix.indrelid = c.conrelid and
                                 ix.indexrelid = c.conindid and
                                 c.contype in ('p', 'u', 'x'))
+                        left outer join
+                            pg_am am
+                            on i.relam = am.oid
               WHERE
                   t.relkind IN ('r', 'v', 'f', 'm')
                   and t.oid = :table_oid
@@ -2682,7 +2688,7 @@ class PGDialect(default.DefaultDialect):
 
         sv_idx_name = None
         for row in c.fetchall():
-            idx_name, unique, expr, prd, col, col_num, conrelid, idx_key, options = row
+            idx_name, unique, expr, prd, col, col_num, conrelid, idx_key, options, amname = row
 
             if expr:
                 if idx_name != sv_idx_name:
@@ -2710,6 +2716,8 @@ class PGDialect(default.DefaultDialect):
                     index['duplicates_constraint'] = idx_name
                 if options:
                     index['options'] = dict([option.split("=") for option in options])
+                if amname and amname != 'btree':
+                    index['amname'] = amname
 
         result = []
         for name, idx in indexes.items():
@@ -2722,6 +2730,8 @@ class PGDialect(default.DefaultDialect):
                 entry['duplicates_constraint'] = idx['duplicates_constraint']
             if 'options' in idx:
                 entry.setdefault('dialect_options', {})["postgresql_with"] = idx['options']
+            if 'amname' in idx:
+                entry.setdefault('dialect_options', {})["postgresql_using"] = idx['amname']
             result.append(entry)
         return result
 
diff --git a/test/dialect/postgresql/test_reflection.py b/test/dialect/postgresql/test_reflection.py
index 70b81219e..2321a3054 100644
--- a/test/dialect/postgresql/test_reflection.py
+++ b/test/dialect/postgresql/test_reflection.py
@@ -12,6 +12,7 @@ from sqlalchemy import Table, Column, MetaData, Integer, String, \
 from sqlalchemy import exc
 import sqlalchemy as sa
 from sqlalchemy.dialects.postgresql import base as postgresql
+from sqlalchemy.dialects.postgresql import ARRAY
 
 
 class ForeignTableReflectionTest(fixtures.TablesTest, AssertsExecutionResults):
@@ -691,6 +692,24 @@ class ReflectionTest(fixtures.TestBase):
                    'dialect_options': {"postgresql_with": {"fillfactor": "50"}}}])
         conn.close()
 
+    @testing.provide_metadata
+    def test_index_reflection_with_access_method(self):
+        """reflect indexes with storage options set"""
+
+        metadata = self.metadata
+
+        t1 = Table('t', metadata,
+                   Column('id', Integer, primary_key=True),
+                   Column('x', ARRAY(Integer))
+                   )
+        metadata.create_all()
+        conn = testing.db.connect().execution_options(autocommit=True)
+        conn.execute("CREATE INDEX idx1 ON t USING gin (x)")
+
+        ind = testing.db.dialect.get_indexes(conn, "t", None)
+        eq_(ind, [{'unique': False, 'column_names': ['x'], 'name': 'idx1',
+                   'dialect_options': {'postgresql_using': 'gin'}}])
+        conn.close()
 
     @testing.provide_metadata
     def test_foreign_key_option_inspection(self):