Revert "perf: Optimize content_type filtering with computed column and indexes (#868)"

This reverts commit 3992920.

Author: nesitor

deployment/migrations/versions/0040_83a04f64a1db_add_content_type_as_field.py

@@ -130,7 +130,9 @@ def make_matching_messages_query(
             MessageDb.content["item_hash"].astext.in_(content_hashes)
         )
     if content_types:
-        select_stmt = select_stmt.where(MessageDb.content_type.in_(content_types))
+        select_stmt = select_stmt.where(
+            MessageDb.content["type"].astext.in_(content_types)
+        )
     if tags:
         select_stmt = select_stmt.where(
             MessageDb.content["content"]["tags"].has_any(array(tags))
@@ -314,7 +316,7 @@ def get_unconfirmed_messages(
 def make_message_upsert_query(message: MessageDb) -> Insert:
     return (
         insert(MessageDb)
-        .values(message.to_dict(exclude={"content_type"}))
+        .values(message.to_dict())
         .on_conflict_do_update(
             constraint="messages_pkey",
             set_={"time": func.least(MessageDb.time, message.time)},

src/aleph/db/accessors/messages.py

@@ -18,9 +18,7 @@
     ARRAY,
     TIMESTAMP,
     Column,
-    Computed,
     ForeignKey,
-    Index,
     Integer,
     String,
     Table,
@@ -101,14 +99,6 @@ class MessageDb(Base):
     time: dt.datetime = Column(TIMESTAMP(timezone=True), nullable=False, index=True)
     channel: Optional[Channel] = Column(String, nullable=True, index=True)
     size: int = Column(Integer, nullable=False)
-    content_type: Optional[str] = Column(
-        String, Computed("content->>'type'", persisted=True)
-    )
-
-    __table_args__ = (
-        Index("ix_messages_content_type", content_type),
-        Index("ix_messages_sender_content_type", sender, content_type),
-    )
 
     confirmations: "List[ChainTxDb]" = relationship(
         "ChainTxDb", secondary=message_confirmations