36.44. sql_features
  The table
  
   sql_features
  
  contains information
   about which formal features defined in the SQL standard are
   supported by
  
   PostgreSQL
  
  .  This is the
   same information that is presented in
  
   Appendix D
  
  .
   There you can also find some additional background information.
 
   
    Table 36.42. 
    
     sql_features
    
    Columns
   
  
| Name | Data Type | Description | 
|---|---|---|
       
        feature_id
       
       | 
      
       
        character_data
       
       | 
      Identifier string of the feature | 
       
        feature_name
       
       | 
      
       
        character_data
       
       | 
      Descriptive name of the feature | 
       
        sub_feature_id
       
       | 
      
       
        character_data
       
       | 
      Identifier string of the subfeature, or a zero-length string if not a subfeature | 
       
        sub_feature_name
       
       | 
      
       
        character_data
       
       | 
      Descriptive name of the subfeature, or a zero-length string if not a subfeature | 
       
        is_supported
       
       | 
      
       
        yes_or_no
       
       | 
      
       
        YES
       
       if the feature is fully supported by the
       current version of
       
        PostgreSQL
       
       ,
       
        NO
       
       if not
       | 
     
       
        is_verified_by
       
       | 
      
       
        character_data
       
       | 
      Always null, since the PostgreSQL development group does not perform formal testing of feature conformance | 
       
        comments
       
       | 
      
       
        character_data
       
       | 
      Possibly a comment about the supported status of the feature |