fix(db-migrate): enforce gc collection to optimize memory usage

rhodecode/lib/dbmigrate/versions/115_version_5_1_0.py

@@ -1,50 +1,53 b''
 
 
 import logging
 from sqlalchemy import *
 from sqlalchemy.engine import reflection
 
 from alembic.migration import MigrationContext
 from alembic.operations import Operations
 
 from rhodecode.lib.dbmigrate.versions import _reset_base
 from rhodecode.model import meta, init_model_encryption
 
 
 log = logging.getLogger(__name__)
 
 
 def _get_indexes_list(migrate_engine, table_name):
     inspector = reflection.Inspector.from_engine(migrate_engine)
     return inspector.get_indexes(table_name)
 
 
 def upgrade(migrate_engine):
     """
     Upgrade operations go here.
     Don't create your own engine; bind migrate_engine to your metadata
     """
     from rhodecode.model import db as db_5_1_0_0
 
     # issue fixups
     fixups(db_5_1_0_0, meta.Session)
 
 
 def downgrade(migrate_engine):
     pass
 
 
 def fixups(models, _SESSION):
+
     for db_repo in _SESSION.query(models.Repository).all():
 
+        try:
         config = db_repo._config
         config.set('extensions', 'largefiles', '')
 
-        try:
-            scm = db_repo.scm_instance(cache=False, config=config)
+            scm = db_repo.scm_instance(cache=False, config=config, vcs_full_cache=False)
             if scm:
                 print(f'installing hook for repo: {db_repo}')
                 scm.install_hooks(force=True)
+            del scm  # force GC
+            del config
         except Exception as e:
             print(e)
             print('continue...')