When using the jpa-generate-entities-from-tables command forge eventually asks for a --hibernate dialect and lists the deprecated org.hibernate.dialect.PostgreSQLDialect (option 9) instead of the newer PostgreSQL82Dialect which isn't listed at all:

[0] ( ) org.hibernate.dialect.MySQL5Dialect
[1] ( ) org.hibernate.dialect.MySQL5InnoDBDialect
[2] ( ) org.hibernate.dialect.MySQLMyISAMDialect
[3] ( ) org.hibernate.dialect.OracleDialect
[4] ( ) org.hibernate.dialect.Oracle9iDialect
[5] ( ) org.hibernate.dialect.Oracle10gDialect
[6] ( ) org.hibernate.dialect.DB2Dialect
[7] ( ) org.hibernate.dialect.DB2400Dialect
[8] ( ) org.hibernate.dialect.DB2390Dialect
[9] ( ) org.hibernate.dialect.PostgreSQLDialect
[10] ( ) org.hibernate.dialect.SQLServerDialect
[11] ( ) org.hibernate.dialect.SQLServer2005Dialect
[12] ( ) org.hibernate.dialect.SQLServer2008Dialect
[13] ( ) org.hibernate.dialect.SAPDBDialect
[14] ( ) org.hibernate.dialect.InformixDialect
[15] ( ) org.hibernate.dialect.HSQLDialect
[16] ( ) org.hibernate.dialect.H2Dialect
[17] ( ) org.hibernate.dialect.IngresDialect
[18] ( ) org.hibernate.dialect.ProgressDialect
[19] ( ) org.hibernate.dialect.MckoiDialect
[20] ( ) org.hibernate.dialect.InterbaseDialect
[21] ( ) org.hibernate.dialect.PointbaseDialect
[22] ( ) org.hibernate.dialect.FrontbaseDialect
[23] ( ) org.hibernate.dialect.FirebirdDialect
[24] ( ) org.hibernate.dialect.SybaseASE15Dialect
[25] ( ) org.hibernate.dialect.SybaseAnywhereDialect