It's forbidden to perform queries joining by entities that only contain data in the SQL schema of the shard by default

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 6.1.1 CE GA2, 6.1.20 EE GA2, 6.1.30 EE GA3, 6.2.0 CE M6
• Fix Version/s: 6.1.2 CE GA3, 6.1.30 EE GA3, 6.2.0 CE M6
• Component/s: Core Infrastructure, Core Infrastructure > Sharding, Portal Services > Store
• Labels:
  • backend_test
  • sharding
  • sql
• Environment: Sharding
• Branch Version/s:
  6.1.x
• Backported to Branch:
  Committed
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/11687

There are several SQL tables that only contains data in the shard by default:
(see com.liferay.portal.dao.shard.advice.ShardPersistenceAdvice.java):

• ClassName
• Company
• CounterFinder
• Counter
• PortalPreferences
• Release
• ResourceAction
• ServiceComponent
• Shard
• VirtualHost

So we shouldn't perform queries joining by these tables since in the rest of the shards is not going to return any results. We currently have have two cases:
(see /liferay-portal/portal-impl/src/custom-sql/portal.xml)

• com.liferay.portal.service.persistence.RoleFinder.findByC_N_S_P_A
• com.liferay.portal.service.persistence.RoleFinder.findByR_N_A