ERROR: relation * already exists - during migrating from MySQL to PostgreSQL

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 Beta 3
• Fix Version/s: 7.0.0 Beta 3
• Component/s: Core Infrastructure, Environments, Environments > Databases
• Labels: None
• Story Points: 1.25
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/34155

Steps to reproduce:

1. Start portal with MySQL.
2. Migrate to PostgreSQL.

Actual results:
Many errors like relation already exists:

03:47:59,367 ERROR [liferay/convert_process-1][ModelMigratorImpl:189] org.postgresql.util.PSQLException: ERROR: relation "group_" already exists
org.postgresql.util.PSQLException: ERROR: relation "group_" already exists
	at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2270)
	at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1998)
	at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:570)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:334)
	at com.zaxxer.hikari.pool.ProxyStatement.executeUpdate(ProxyStatement.java:120)
	at com.zaxxer.hikari.pool.HikariProxyStatement.executeUpdate(HikariProxyStatement.java)
	at com.liferay.portal.dao.db.BaseDB.runSQL(BaseDB.java:281)
	at com.liferay.portal.dao.db.BaseDB.runSQL(BaseDB.java:251)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrateTable(ModelMigratorImpl.java:184)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrateModel(ModelMigratorImpl.java:152)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrate(ModelMigratorImpl.java:77)
	at com.liferay.portal.convert.database.PortalDatabaseConverter.convert(PortalDatabaseConverter.java:37)
	at com.liferay.portal.convert.database.DatabaseConvertProcess.doConvert(DatabaseConvertProcess.java:82)
	at com.liferay.portal.convert.BaseConvertProcess.convert(BaseConvertProcess.java:43)
	at com.liferay.portal.convert.messaging.ConvertProcessMessageListener.doReceive(ConvertProcessMessageListener.java:48)
	at com.liferay.portal.convert.messaging.ConvertProcessMessageListener.receive(ConvertProcessMessageListener.java:33)
	at com.liferay.portal.kernel.messaging.InvokerMessageListener.receive(InvokerMessageListener.java:72)
	at com.liferay.portal.kernel.messaging.SerialDestination$1.run(SerialDestination.java:58)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask._runTask(ThreadPoolExecutor.java:756)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask.run(ThreadPoolExecutor.java:667)
	at java.lang.Thread.run(Thread.java:724)

03:47:59,381 ERROR [liferay/convert_process-1][ModelMigratorImpl:189] org.postgresql.util.PSQLException: ERROR: relation "groups_orgs" already exists
org.postgresql.util.PSQLException: ERROR: relation "groups_orgs" already exists
	at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2270)
	at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1998)
	at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:570)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:406)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:334)
	at com.zaxxer.hikari.pool.ProxyStatement.executeUpdate(ProxyStatement.java:120)
	at com.zaxxer.hikari.pool.HikariProxyStatement.executeUpdate(HikariProxyStatement.java)
	at com.liferay.portal.dao.db.BaseDB.runSQL(BaseDB.java:281)
	at com.liferay.portal.dao.db.BaseDB.runSQL(BaseDB.java:251)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrateTable(ModelMigratorImpl.java:184)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrateModel(ModelMigratorImpl.java:152)
	at com.liferay.portal.convert.util.ModelMigratorImpl.migrate(ModelMigratorImpl.java:77)
	at com.liferay.portal.convert.database.PortalDatabaseConverter.convert(PortalDatabaseConverter.java:37)
	at com.liferay.portal.convert.database.DatabaseConvertProcess.doConvert(DatabaseConvertProcess.java:82)
	at com.liferay.portal.convert.BaseConvertProcess.convert(BaseConvertProcess.java:43)
	at com.liferay.portal.convert.messaging.ConvertProcessMessageListener.doReceive(ConvertProcessMessageListener.java:48)
	at com.liferay.portal.convert.messaging.ConvertProcessMessageListener.receive(ConvertProcessMessageListener.java:33)
	at com.liferay.portal.kernel.messaging.InvokerMessageListener.receive(InvokerMessageListener.java:72)
	at com.liferay.portal.kernel.messaging.SerialDestination$1.run(SerialDestination.java:58)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask._runTask(ThreadPoolExecutor.java:756)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask.run(ThreadPoolExecutor.java:667)
	at java.lang.Thread.run(Thread.java:724)