zulip/zerver/management/commands/create_large_indexes.py

96 lines
3.1 KiB
Python

from typing import Any, Callable, Dict, List, Set, Text
from django.db import connection
from zerver.lib.management import ZulipBaseCommand
def create_index_if_not_exist(index_name: Text, table_name: Text,
column_string: Text, where_clause: Text) -> None:
#
# This function is somewhat similar to
# zerver.lib.migrate.create_index_if_not_exist.
#
# The other function gets used as part of Django migrations; this function
# uses SQL that is not supported by Django migrations.
#
# Creating concurrent indexes is kind of a pain with current versions
# of Django/postgres, because you will get this error with seemingly
# reasonable code:
#
# CREATE INDEX CONCURRENTLY cannot be executed from a function or multi-command string
#
# For a lot more detail on this process, refer to the commit message
# that added this file to the repo.
with connection.cursor() as cursor:
sql = '''
SELECT 1
FROM pg_class
where relname = %s
'''
cursor.execute(sql, [index_name])
rows = cursor.fetchall()
if len(rows) > 0:
print('Index %s already exists.' % (index_name,))
return
print("Creating index %s." % (index_name,))
sql = '''
CREATE INDEX CONCURRENTLY
%s
ON %s (%s)
%s;
''' % (index_name, table_name, column_string, where_clause)
cursor.execute(sql)
print('Finished creating %s.' % (index_name,))
def create_indexes() -> None:
# copied from 0082
create_index_if_not_exist(
index_name='zerver_usermessage_starred_message_id',
table_name='zerver_usermessage',
column_string='user_profile_id, message_id',
where_clause='WHERE (flags & 2) != 0',
)
# copied from 0083
create_index_if_not_exist(
index_name='zerver_usermessage_mentioned_message_id',
table_name='zerver_usermessage',
column_string='user_profile_id, message_id',
where_clause='WHERE (flags & 8) != 0',
)
# copied from 0095
create_index_if_not_exist(
index_name='zerver_usermessage_unread_message_id',
table_name='zerver_usermessage',
column_string='user_profile_id, message_id',
where_clause='WHERE (flags & 1) = 0',
)
# copied from 0098
create_index_if_not_exist(
index_name='zerver_usermessage_has_alert_word_message_id',
table_name='zerver_usermessage',
column_string='user_profile_id, message_id',
where_clause='WHERE (flags & 512) != 0',
)
# copied from 0099
create_index_if_not_exist(
index_name='zerver_usermessage_wildcard_mentioned_message_id',
table_name='zerver_usermessage',
column_string='user_profile_id, message_id',
where_clause='WHERE (flags & 8) != 0 OR (flags & 16) != 0',
)
class Command(ZulipBaseCommand):
help = """Create concurrent indexes for large tables."""
def handle(self, *args: Any, **options: str) -> None:
create_indexes()