diff --git a/lbry/db/query_context.py b/lbry/db/query_context.py
index a33909aea..e2728d361 100644
--- a/lbry/db/query_context.py
+++ b/lbry/db/query_context.py
@@ -1,5 +1,6 @@
 import os
 import time
+import traceback
 import functools
 from io import BytesIO
 import multiprocessing as mp
@@ -160,7 +161,7 @@ def context(with_timer: str = None) -> 'QueryContext':
 
 def set_postgres_settings(connection, _):
     cursor = connection.cursor()
-    cursor.execute('SET work_mem="100MB";')
+    cursor.execute('SET work_mem="500MB";')
     cursor.close()
 
 
@@ -241,7 +242,11 @@ def event_emitter(name: str, *units: str, throttle=1):
         @functools.wraps(f)
         def with_progress(*args, **kwargs):
             with progress(event, throttle=throttle) as p:
-                return f(*args, **kwargs, p=p)
+                try:
+                    return f(*args, **kwargs, p=p)
+                except:
+                    traceback.print_exc()
+                    raise
         return with_progress
 
     return wrapper
@@ -546,7 +551,7 @@ class BulkLoader:
         if claim.is_signed:
             d['channel_hash'] = claim.signing_channel_hash
             d['is_signature_valid'] = (
-                all((signature, signature_digest, channel_public_key)) &
+                all((signature, signature_digest, channel_public_key)) and
                 Output.is_signature_valid(
                     signature, signature_digest, channel_public_key
                 )
@@ -584,7 +589,7 @@ class BulkLoader:
             if support.is_signed:
                 d['channel_hash'] = support.signing_channel_hash
                 d['is_signature_valid'] = (
-                    all((signature, signature_digest, channel_public_key)) &
+                    all((signature, signature_digest, channel_public_key)) and
                     Output.is_signature_valid(
                         signature, signature_digest, channel_public_key
                     )
diff --git a/lbry/db/tables.py b/lbry/db/tables.py
index 0d83f65ab..b8fe1e0ed 100644
--- a/lbry/db/tables.py
+++ b/lbry/db/tables.py
@@ -5,7 +5,7 @@ from sqlalchemy import (
     LargeBinary, Text, SmallInteger, Integer, BigInteger, Boolean,
     text
 )
-from .constants import TXO_TYPES
+from .constants import TXO_TYPES, CLAIM_TYPE_CODES
 
 
 SCHEMA_VERSION = '1.4'
@@ -97,16 +97,34 @@ txo_join_account = TXO.join(AccountAddress, TXO.columns.address == AccountAddres
 
 def pg_add_txo_constraints_and_indexes(execute):
     execute(text("ALTER TABLE txo ADD PRIMARY KEY (txo_hash);"))
+    # find appropriate channel public key for signing a content claim
     execute(text(f"""
         CREATE INDEX txo_channel_hash_w_height_desc_and_pub_key
         ON txo (claim_hash, height desc) INCLUDE (public_key)
         WHERE txo_type={TXO_TYPES['channel']};
     """))
+    # update supports for a claim
     execute(text(f"""
         CREATE INDEX txo_unspent_supports
         ON txo (claim_hash) INCLUDE (amount)
         WHERE spent_height = 0 AND txo_type={TXO_TYPES['support']};
     """))
+    # claim changes by height
+    execute(text(f"""
+        CREATE INDEX txo_claim_changes
+        ON txo (height DESC) INCLUDE (txo_hash)
+        WHERE spent_height = 0 AND txo_type IN {tuple(CLAIM_TYPE_CODES)};
+    """))
+    # supports added
+    execute(text(f"""
+        CREATE INDEX txo_added_supports_by_height ON txo (height DESC)
+        INCLUDE (claim_hash) WHERE txo_type={TXO_TYPES['support']};
+    """))
+    # supports spent
+    execute(text(f"""
+        CREATE INDEX txo_spent_supports_by_height ON txo (spent_height DESC)
+        INCLUDE (claim_hash) WHERE txo_type={TXO_TYPES['support']};
+    """))
 
 
 TXI = Table(
@@ -187,6 +205,9 @@ Claim = Table(
 
 def pg_add_claim_constraints_and_indexes(execute):
     execute(text("ALTER TABLE claim ADD PRIMARY KEY (claim_hash);"))
+    # finding claims that aren't updated with latest TXO
+    execute(text("CREATE INDEX claim_txo_hash ON claim (txo_hash);"))
+    # used to calculate content in a channel
     execute(text("""
         CREATE INDEX signed_content ON claim (channel_hash)
         INCLUDE (amount) WHERE is_signature_valid;