code: protected Integer getIdentifierLengthLimit(JdbcEnvironment context) {
          // https://docs.jboss.org/hibernate/orm/5.0/javadocs/org/hibernate/dialect/package-summary.html
          String dialectName = context.getDialect().getClass().getSimpleName();
  
          if (dialectName.startsWith("Oracle")) {
              // identifier limit of 30 chars -->
              // http://stackoverflow.com/a/756569
              return LENGTH_LIMIT_ORACLE;
          } else if (context.getDialect() instanceof ShogunCoreOracleDialect) {
              // identifier limit of 30 chars -->
              return LENGTH_LIMIT_ORACLE;
          } else if (dialectName.startsWith("PostgreSQL")) {
              // identifier limit of 63 chars -->
              // http://stackoverflow.com/a/8218026
              return LENGTH_LIMIT_POSTGRESQL;
          }
          // H2 has no limit --> http://stackoverflow.com/a/30477403
  
          return null;
      }
docs: Determines the identifier length limit for the given JDBC context.
  Returns null if no limitation is necessary.
  
  @param context The current JDBC context
  @return The identifier length limit for the given context. null
  otherwise.