diff --git a/lbry/blockchain/sync/steps.py b/lbry/blockchain/sync/steps.py
index 93637dacc..f6189db9b 100644
--- a/lbry/blockchain/sync/steps.py
+++ b/lbry/blockchain/sync/steps.py
@@ -4,7 +4,7 @@ from contextvars import ContextVar
 from functools import partial
 from typing import Optional, Tuple
 
-from sqlalchemy import bindparam, case, distinct, text, func, between, desc
+from sqlalchemy import table, bindparam, case, distinct, text, func, between, desc
 from sqlalchemy.future import select
 from sqlalchemy.schema import CreateTable
 
@@ -170,17 +170,14 @@ def process_spends(initial_sync: bool, p: ProgressContext):
             p.ctx.execute(text("ALTER TABLE txo DROP CONSTRAINT txo_pkey;"))
         p.step(next_step())
         # G. insert
-        old_txo = TXO.alias('old_txo')
+        old_txo = table('old_txo', *(c.copy() for c in TXO.columns))
         columns = [c for c in old_txo.columns if c.name != 'spent_height']
         select_columns = columns + [func.coalesce(TXI.c.height, 0).label('spent_height')]
         insert_columns = columns + [TXO.c.spent_height]
-        select_txos = select(*select_columns).select_from(old_txo.join(TXI, isouter=True))
+        join_txo_on_txi = old_txo.join(TXI, old_txo.c.txo_hash == TXI.c.txo_hash, isouter=True)
+        select_txos = (select(*select_columns).select_from(join_txo_on_txi))
         insert_txos = TXO.insert().from_select(insert_columns, select_txos)
-        p.ctx.execute(text(
-            str(insert_txos.compile(p.ctx.engine))
-            .replace('txo AS old_txo', 'old_txo')
-            .replace('%(coalesce_1)s', '0')
-        ))
+        p.ctx.execute(insert_txos)
         p.step(next_step())
         # H. drop old txo
         p.ctx.execute(text("DROP TABLE old_txo;"))
diff --git a/lbry/db/queries.py b/lbry/db/queries.py
index e5365dd49..bc580dad3 100644
--- a/lbry/db/queries.py
+++ b/lbry/db/queries.py
@@ -39,8 +39,6 @@ log = logging.getLogger(__name__)
 
 def check_version_and_create_tables():
     with context("db.connecting") as ctx:
-        if ctx.is_sqlite:
-            ctx.execute(text("PRAGMA journal_mode=WAL;"))
         if ctx.has_table('version'):
             version = ctx.fetchone(select(Version.c.version).limit(1))
             if version and version['version'] == SCHEMA_VERSION:
diff --git a/lbry/db/query_context.py b/lbry/db/query_context.py
index 2e0362262..4d0de0ac7 100644
--- a/lbry/db/query_context.py
+++ b/lbry/db/query_context.py
@@ -8,7 +8,7 @@ from typing import Dict, List, Optional, Tuple
 from dataclasses import dataclass, field
 from contextvars import ContextVar
 
-from sqlalchemy import create_engine, inspect, bindparam, func, exists, case
+from sqlalchemy import create_engine, inspect, bindparam, func, exists, case, event
 from sqlalchemy.future import select
 from sqlalchemy.engine import Engine, Connection
 from sqlalchemy.sql import Insert
@@ -158,11 +158,27 @@ def context(with_timer: str = None) -> 'QueryContext':
     return _context.get()
 
 
+def set_postgres_settings(connection, _):
+    cursor = connection.cursor()
+    cursor.execute('SET work_mem="100MB";')
+    cursor.close()
+
+
+def set_sqlite_settings(connection, _):
+    cursor = connection.cursor()
+    cursor.execute('PRAGMA journal_mode=WAL;')
+    cursor.close()
+
+
 def initialize(
         ledger: Ledger, message_queue: mp.Queue, stop_event: mp.Event,
         track_metrics=False, block_and_filter=None, print_timers=None):
     url = ledger.conf.db_url_or_default
     engine = create_engine(url)
+    if engine.name == "postgresql":
+        event.listen(engine, "connect", set_postgres_settings)
+    elif engine.name == "sqlite":
+        event.listen(engine, "connect", set_sqlite_settings)
     connection = engine.connect()
     if block_and_filter is not None:
         blocked_streams, blocked_channels, filtered_streams, filtered_channels = block_and_filter
diff --git a/lbry/db/sync.py b/lbry/db/sync.py
index 492c8c670..9463e540d 100644
--- a/lbry/db/sync.py
+++ b/lbry/db/sync.py
@@ -68,6 +68,7 @@ def update_spent_outputs(ctx):
             TXO.c.spent_height: (
                 select(TXI.c.height)
                 .where(TXI.c.txo_hash == TXO.c.txo_hash)
+                .scalar_subquery()
             )
         }).where(
             (TXO.c.spent_height == 0) &