Failed to start demo

WARN: GenerationTarget encountered exception accepting command : Error executing DDL via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlString(AbstractSchemaMigrator.java:524)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlStrings(AbstractSchemaMigrator.java:470)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applyForeignKeys(AbstractSchemaMigrator.java:429)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:245)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:110)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:177)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:66)
at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:309)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:445)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:710)
at com.cockroachlabs.util.SessionUtil.(SessionUtil.java:64)
at com.cockroachlabs.util.SessionUtil.init(SessionUtil.java:68)
at com.cockroachlabs.Application.initHibernate(Application.java:33)
at com.cockroachlabs.Application.run(Application.java:28)
at com.cockroachlabs.Application.main(Application.java:24)
Caused by: org.postgresql.util.PSQLException: ERROR: columns cannot be used by multiple foreign key constraints
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2284)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2003)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:200)

Start with com.cockroachlabs.Application.initHibernate and com.cockroachlabs.util.SessionUtil, then inspect the Hibernate schema-generation configuration that runs during startup. Reproduce the demo failure and trace the generated DDL associated with the PostgreSQL error about columns being used by multiple foreign key constraints; done means the demo starts without this exception.

索引モデルが issue の本文から書いたものです。