Introduction
Dans mon article "Trouver les objets Oracle cachés : tables système xxx$, structures mémoire X$xxx, paramètres cachés, packages PL/SQL cachés"
je parlais des structures mémoires X$xxx. Celles-ci ont des noms très particuliers comme X$KSDAFT ou X$KQFOPT et je vous mets au défi de deviner à quoi elles servent rien qu'avec leur nom!

Malheureusement ces structures mémoires ne sont pas documentées par Oracle et il est extrêmement difficile de trouver des infos sur le net sur leur nommage. Mais, en cherchant pendant longtemps, on arrive quand même à comprendre comment leur nom se compose.




Points d'attention
Ces structures mémoires n'étant pas documentées par Oracle, je vous conseille d'utiliser les vues dynamiques de performances V$ basées sur ces structures qui, elles, sont parfaitement documentées.



Base de tests
N'importe quelle base Oracle.




Exemples
============================================================================================
Sites web donnant la liste de ces structures mémoires X$xxx

============================================================================================
Ces objets excitent beaucoup les DBA car ce sont eux qui renferment les informations les plus précises sur ce qui se passe en base.Ils ont même parfois des infos non reprises dans les vues V$xxx; par exemple le champ TCH de X$BH est LE champ qui indique la popularité d'un bloc et c'est sa valeur qui dit si ce bloc va rester dans le Database Buffer Cache ou va en être éjecté pour laisser la place à des blocs plus populaires.

Pour cette raison, plusieurs sites web en donnent une liste plus ou moins détaillées MAIS sans expliquer comment leur nom est construit.

Sur le site de Daniel MORGAN, on a une liste impressionnante de ces structures pour Oracle 12c, classées par catégories avec même des explications sur leur rôle.
La page est ici : http://www.morganslibrary.org/reference/xdollarsign.ht

Il a même commencé pour Oracle 12c à classer ces structures mémoires selon les deux premières lettres de leur nom mais il n'est pas allé plus loin. La page est ici : http://www.morganslibrary.org/reference/kernel_subsystems.html et la liste complète est la suivante :
          KA Access Layer
          KC Cache Layer
          KD Data Layer
          KG Generic Layer
          KJ Lock Manager Layer
          KK Compilation Layer - Parse SQL, compile PL/SQL
          KQ Query Layer
          KS Services Layer
          KT Transaction Layer
          KV Kernel Variables (eg. x$KVIS and X$KVII)
          KX Execution Layer - Bind and execute SQL and PL/SQL
          KZ Security Layer - Validate privs
          K2 Distributed Execution Layer - 2PC handling
          NPI Network Program Interface
          ODS Operating System Dependencies
          OPI Oracle Program Interface
          RPI Recursive Program Interface
          S Operating System Dependencies

On trouve également sur le site de Donald K. BURLESON une liste de ces structures mémoires mais, à nouveau, sans détail sur la construction de leur nom. La page est ici : http://www.oracle-training.cc/oracle_tips_x$.htm. Attention, il s'agit d'une liste venant d'une version 8.1.5 d'Oracle.
         X$ks – Kernel Services
         x$ksmfs kernel services, memory fixed SGA
         x$ksmfsv kernel services, memory fixed SGA vectors
         x$ksmjs kernel services, memory java_pool summary
         x$ksmlru kernel services, memory LRU
         x$ksmls kernel services, memory large_pool summary
         x$ksmmem kernel services, memory
         x$ksmpp kernel services, memory process pool
         x$ksmsd kernel services, memory SGA definition
         x$ksmsp kernel services, memory shared pool
         x$ksmspr kernel services, memory shared pool reserved
         x$ksmss kernel services, memory shared_pool summary
         x$ksmup kernel services, memory user pool
         x$ksqst kernel services, enqueue status
         x$ksulop kernel services, user long operation
         x$ksulv kernel services, user locale value
         x$ksupr kernel services, user process

         X$kc – kernel cache
         x$kcbfwait kernel cache, block file wait
         x$kcbwait kernel cache, block wait
         x$kcccp kernel cache, controlfile checkpoint progress
         x$kcfio kernel cache, file I/O
         x$kclfh kernel cache, lock file header
         x$kclfi kernel cache, lock file index
         x$kcluh kernel cache, lock undo header
         x$kclui kernel cache, lock undo index

         X$kq – kernel query
         x$kqfco kernel query, fixed table columns
         x$kqfdt kernel query, fixed table
         x$kqfp kernel query, fixed procedure
         x$kqfsz kernel query, fixed size
         x$kqfta kernel query, fixed table
         x$kqfvi kernel query, fixed view
         x$kqfvt kernel query, fixed view table

         X$kg – kernel generic
         x$kghlu kernel generic, heap LRUs
         x$kgllk kernel generic, library cache lock
         x$kglob kernel generic, library cache object
         x$kglpn kernel generic, library cache pin
         x$kglst kernel generic, library cache status

         X$kz – Kernel security
         x$kzsro kernel security, system role

         X$le – lock element
         x$le lock element
         x$le_stat lock element status


============================================================================================
Site web expliquant comment sont nommées ces structures mémoires X$xxx

============================================================================================

C'est finalement sur le site http://www.eygle.com/refer/Oracle_x$table_list.htm que j'ai trouvé l'explication sur le nommage des structures, et ce lettre par lettre! Je recopie intégralement ici ce mail pour en faire une sauvegarde car j'ai beaucoup galéré pour trouver cette information.

Vous noterez les commentaires suivant : 
          ** INTERNAL ONLY **, comme si cette liste venait d'un mail d'un employé Oracle

          "The main purpose of this note is to show the naming conventions" ce qui est EXACTEMENT ce que je cherchais.


ATTENTION : la liste concerne la base de données d'Oracle 7.3.2 et la dernière révision du post remonte à septembre 1999!
Certes cette liste est en partie dépassée MAIS plusieurs de ces objets existent encore et je pense qu'Oracle a continué à nommer les nouvelles structures en utilisant cette nomenclature et ce classement.


Doc ID: Note:22241.1
Subject: List of X$ Tables and how the names are derived 
Type: REFERENCE
Status: PUBLISHED
Content Type: TEXT/PLAIN
Creation Date: 14-MAR-1995
Last Revision Date: 23-SEP-1999 
Language: USAENG
** INTERNAL ONLY **
This is a summary list of X$ Table Definitions - Last revision was 7.3.2
The main purpose of this note is to show the naming conventions.

  [K]ernel Layer                                                                
    [2]-Phase Commit                                                            
      [G]lobal [T]ransaction [E]ntry                                            
        X$K2GTE  - Current 2PC tx                                               
        X$K2GTE2 - Current 2PC tx                                               

    [C]ache Layer                                                               
      [B]uffer Management                                                       
        Buffer [H]ash                                                           
          X$BH - Hash Table                                                     
        Buffer LRU Statistics                                                   
          X$KCBCBH - [C]urrent [B]uffers (buckets) - lru_statistics             
          X$KCBRBH - [R]ecent [B]uffers (buckets) - lru_extended                
        Buffer [WAIT]s                                                          
          X$KCBWAIT  - Waits by block class                                     
          X$KCBFWAIT - Waits by File                                            
        [W]orking Sets - 7.3 or higher                                          
          X$KCBWDS - Set [D]escriptors                                          

      [C]ontrol File Management                                                 
        [C]ontrol [F]ile List - 7.0.16 or higher                                
          X$KCCCF - Control File Names & status                                 
        [D]atabase [I]nformation                                                
          X$KCCDI - Database Information                                        
        Data [F]iles                                                            
          X$KCCFE - File [E]ntries ( from control file )                        
          X$KCCFN - [F]ile [N]ames                                              
        [L]og Files                                                             
          X$KCCLE - Log File [E]ntries                                          
          X$KCCLH - Log [H]istory ( archive entries )                           
        Thread Information                                                      
          X$KCCRT - [R]edo [T]hread Information                                 

      [F]ile Management                                                         
        X$KCFIO - File [IO] Statistics                                          

      [L]ock Manager Component ( LCK )                                          
        [H]ash and Bucket Tables - 7.0.15 to 7.1.1, and 7.2.0 or higher         
          X$KCLFH - File [H]ash Table                                           
          X$KCLFI - File Bucket Table                                           
        X$LE - Lock [E]lements                                                  
        X$LE_STAT - Lock Conversion [STAT]istics                                
        X$KCLFX - Lock Element [F]ree list statistics - 7.3 or higher           
        X$KCLLS - Per LCK free list statistics - 7.3 or higher                  
        X$KCLQN - [N]ame (hash) table statistics - 7.3 or higher                

      [R]edo Component                                                          
        [M]edia recovery  - kcra.h - 7.3 or higher                              
          X$KCRMF - [F]ile context                                              
          X$KCRMT - [T]hread context                                            
          X$KCRMX - Recovery Conte[X]t                                          
        [F]ile read                                                             
          X$KCRFX - File Read Conte[X]t -  7.3 or higher                        
      Reco[V]ery Component                                                      
        [F]ile [H]eaders                                                        
          X$KCVFH - All file headers                                            
          X$KCVFHMRR - Files with [M]edia [R]ecovery [R]equired                 
          X$KCVFHONL - [ONL]ine File headers                                    

      [K]ompatibility Management - 7.1.1 or higher                              
        X$KCKCE - [C]ompatibility Segment [E]ntries                             
        X$KCKTY - Compatibility [TY]pes                                         
        X$KCKFM - Compatibility [F]or[M]ats ( index into X$KCKCE )              

    [D]ata Layer                                                                
      Sequence [N]umber Component                                               
         X$KDNCE - Sequence [C]ache [E]ntries - 7.2 or lower                     
        [S]equence Enqueues - common area for enqueue objects                   
          X$KDNSSC - [C]ache Enqueue Objects - 7.2 or lower                     
          X$KDNSSF - [F]lush Enqueue Objects - 7.2 or lower                     
        X$KDNST - Cache [ST]atistics - 7.2 or lower                             

      Inde[X] Block Component                                                   
        X$KDXHS - Index [H]i[S]togram                                           
        X$KDXST - Index [ST]atistics                                            

    [G]eneric Layer                                                             
      [H]eap Manager                                                            
        X$KGHLU - State (summary) of [L]R[U] heap(s) - defined in ksmh.h        

      [I]nstantiation Manager                                                   
        [C]ursor [C]ache                                                        
          X$KGICC - Session statistics - defined in kqlf.h                      
          X$KGICS - System wide statistics - defined in kqlf.h                  

      [L]ibrary Cache Manager  ( defined and mapped from kqlf )                 
        Bind Variables                                                          
          X$KKSBV - Library Object [B]ind [V]ariables                           
        Object Cache                                                            
          X$KGLOB - All [OB]jects                                               
          X$KGLTABLE   - Filter for [TABLE]s                                    
          X$KGLBODY    - Filter for [BODY] ( packages )                         
          X$KGLTRIGGER - Filter for [TRIGGER]s                                  
          X$KGLINDEX   - Filter for [INDEX]es                                   
          X$KGLCLUSTER - Filter for [CLUSTER]s                                  
          X$KGLCURSOR  - Filter for [CURSOR]s                                   
        Cache Dependency                                                        
          X$KGLDP - Object [D]e[P]endency table                                 
          X$KGLRD - [R]ead only [D]ependency table - 7.3 or higher              
        Object Locks                                                            
          X$KGLLK - Object [L]oc[K]s                                            
        Object Names                                                            
          X$KGLNA - Object [NA]mes (sql text)                                   
          X$KGLNA1 - Object [NA]mes (sql text) with newlines - 7.2.0 or higher  
        Object Pins                                                             
          X$KGLPN - Object [P]i[N]s                                             
        Cache Statistics                                                        
          X$KGLST - Library cache [ST]atistics                                  
        Translation Table                                                       
          X$KGLTR - Address [TR]anslation                                       
        Access Table                                                            
          X$KGLXS - Object Access Table                                         
        Authorization Table - 7.1.5 or higher                                   
          X$KGLAU - Object Authorization table                                  
        Latch Cleanup - 7.0.15 or higher                                        
          X$KGLLC - [L]atch [C]leanup for Cache/Pin Latches                     

    [K]ompile Layer                                                             
      [S]hared Objects                                                          
        X$KKSAI - Cursor [A]llocation [I]nformation - 7.3.2 or higher           

    [L]oader                                                                    
      [L]ibrary                                                                 
        X$KLLCNT - [C]o[NT]rol Statistics                                       
        X$KLLTAB - [TAB]le Statistics                                           

    [M]ulti-Threaded Layer                                                      
      [C]ircuit component                                                       
        X$KMCQS - Current [Q]ueue [S]tate                                       
        X$KMCVC - [V]irtual [C]ircuit state                                     

      [M]onitor Server/dispatcher                                               
        [D]ispatcher                                                            
          X$KMMDI - [D]ispatcher [I]nfo (status)                                
           X$KMMDP - [D]ispatcher Config ( [P]rotocol info )                     
        [S]erver                                                                
          X$KMMSI - [S]erver [I]nfo ( status )                                  
        X$KMMSG - [SG]a info ( global statistics)                               
        X$KMMRD - [R]equest timing [D]istributions                              

    s[Q]l Version and Option Layer                                              
      Kernel [V]ersions                                                         
        X$VERSION - Library versions                                            
      Kernel [O]ptions - 7.1.3 or higher                                        
        X$OPTION - Server Options                                               

    [Q]uery Layer                                                               
      [D]ictionary Cache Management                                             
        X$KQDPG - [PG]a row cache cursor statistics                             

      [F]ixed Tables/views Management                                           
        X$KQFCO - Table [CO]lumn definitions                                    
        X$KQFDT - [D]erived [T]ables                                            
        X$KQFSZ - Kernel Data structure type [S]i[Z]es                          
        X$KQFTA - Fixed [TA]bles                                                
        X$KQFVI - Fixed [VI]ews                                                 
        X$KQFVT - [V]iew [T]ext definition - 7.2.0 or higher                    

      [R]ow Cache Management                                                    
        X$KQRST - Cache [ST]atistics                                            
        X$KQRPD - [P]arent Cache [D]efinition - 7.1.5 or higher                 
        X$KQRSD - [S]ubordinate Cache [D]efinition - 7.1.5 or higher            

    [S]ervice Layer                                                             
      [B]ackground Management                                                   
        [D]etached Process                                                      
          X$KSBDD - Detached Process [D]efinition (info)                        
          X$KSBDP - Detached [P]rocess Descriptor (name)                        
          X$MESSAGES - Background Message table                                 

      [I]nstance [M]anagement - 7.3 or higher                                   
        X$KSIMAT - Instance [AT]tributes                                        
        X$KSIMAV - [A]ttribute [V]alues for all instances                       
        X$KSIMSI - [S]erial and [I]nstance numbers                              

      [L]ock Management                                                         
        [E]vent Waits                                                           
          X$KSLED - Event [D]escriptors                                         
          X$KSLEI - [I]nstance wide statistics since startup                    
          X$KSLES - Current [S]ession statistics                                
        [L]atches                                                               
          X$KSLLD - Latch [D]escriptor (name)                                   
          X$KSLLT - Latch statistics [ + Child latches @ 7.3 or higher ]        
          X$KSLLW - Latch context ( [W]here ) descriptors - 7.3 or higher       
          X$KSLPO - Latch [PO]st statistics - 7.3 or higher                     
          X$KSLWSC- No[W]ait and [S]leep [C]ount stats by Context -7.3 or higher

      [M]emory Management                                                       
        [C]ontext areas                                                         
          X$KSMCX - E[X]tended statistics on usage - 7.3.1 or lower             
        Heap Areas                                                              
          X$KSMSP - SGA Hea[P]                                                  
          X$KSMPP - [P]GA Hea[P] - 7.3.2 and above                              
          X$KSMUP - [U]GA Hea[P] - 7.3.2 and above                              
          X$KSMHP - Any [H]ea[P] - 7.3.2 and above                              
          X$KSMSPR- [S]hared [P]ool [R]eserved List - 7.1.5 or higher           
        [L]east recently used shared pool chunks                                
          X$KSMLRU - LR[U] flushes from the shared pool                         
        [S]GA Objects                                                           
          X$KSMSD - Size [D]efinition for Fixed/Variable summary                
          X$KSMSS - Statistics (lengths) of SGA objects                         
        SGA [MEM]ory                                                            
           X$KSMMEM - map of the entire SGA - 7.2.0 or higher                    
          X$KSMFSV - Addresses of [F]ixed [S]GA [V]ariables - 7.2.1 or higher   

      [P]arameter Component                                                     
          X$KSPPI  - [P]arameter [I]nfo ( Names )                               
          X$KSPPCV - [C]urrent Session [V]alues - 7.3.2 or above                
          X$KSPPSV - [S]ystem [V]alues - 7.3.2 or above                         

      En[Q]ueue Management                                                      
        X$KSQDN - Global [D]atabase [N]ame                                      
        X$KSQEQ - [E]n[Q]ueue Object                                            
        X$KSQRS - Enqueue [R]e[S]ource                                          
        X$KSQST - Enqueue [S]tatistics by [T]ype                                

      [U]ser Management                                                         
        [C]ost                                                                  
          X$KSUCF - Cost [F]unction (resource limit)                            
        [L]icence                                                               
           X$KSULL - Licence [L]imits                                           
        [L]anguage Manager                                                      
          X$NLS_PARAMETERS - NLS parameters                                     
          X$KSULV - NLS [V]alid Values - 7.1.2 or higher                        
        [MY] [ST]atistics                                                       
          X$KSUMYSTA - [MY] [ST]atisics (current session)                       
        [P]rocess Info                                                          
          X$KSUPL - Process (resource) [L]imits                                 
          X$KSUPRLAT - [LAT]ch Holder                                           
          X$KSUPR - Process object                                              
        [R]esource                                                              
          X$KSURU - Resource [U]sage                                            
        [S]tatistics                                                            
          X$KSUSD - [D]escriptors (statistic names)                             
          X$KSUSGSTA - [G]lobal [ST]atistics                                    
        [SE]ssions                                                              
          X$KSUSECST - Session status for events                                
          X$KSUSESTA - Session [STA]tistics                                     
          X$KSUSECON - [CON]nection Authentication - 7.2.1 or higher            
          X$KSUSE - [SE]ssion Info                                              
          X$KSUSIO - [S]ystem [IO] statistics per session                       
        [T]imer                                                                 
          X$KSUTM - Ti[M]e in 1/100th seconds                                   
        Instance [X]                                                            
          X$KSUXSINST - [INST]ance state                                        
        [T]race management                                                      
          X$TRACE - Current traced events                                       
          X$TRACES - All possible traces                                        
          X$KSTEX - Code [EX]ecution - 7.2.1 or higher                          

      E[X]ecution Management                                                    
        Device/Node [A]ffinity - 7.3.2 and above                                
          X$KSXAFA - Current File/Node Affinity                                 

    [T]ransaction Layer                                                         
      Table [A]ccess [D]efinition                                               
        X$KTADM - D[M]L lock                                                    

      [C]ontrol Component                                                       
        X$KTCXB - Transaction O[B]ject                                          

      [S]or[T] Segments - 7.3 or higher                                         
        X$KTSTSSD - [S]ort [S]egment [D]escriptor - per tablespace statistics   

      [T]ablespace                                                              
        X$KTTVS - [V]alid [S]aveundo                                            

      [U]ndo                                                                    
        X$KTURD - Inuse [D]escriptors                                           
        X$KTUXE - Transaction [E]ntry (table) - 7.3.2 or above                  

    Performance Layer [V] - 7.0.16 or higher                                    
       [I]nformation tables                                                      
        X$KVII - [I]nitialisation Instance parameters                           
        X$KVIS - [S]izes of structure elements                                  
        X$KVIT - [T]ransitory Instance parameters                               

    Security Layer [Z]                                                          
      [D]ictionary Component                                                    
        X$KZDOS - [OS] roles                                                    

      [S]ecurity State                                                          
        X$KZSPR - Enabled [PR]ivileges                                          
        X$KZSRO - Enabled [RO]les                                               

      [R]emote Logins - 7.1.1 or higher                                         
        X$KZSRT - [R]emote Password File [T]able entries                        

    E[X]ecution Layer                                                           
      Parallel Query (Execute [F]ast) - 7.1.1 or higher                         
        [P]rocess and Queue Manager                                             
          Statistics - 7.1.3 or higher                                          
            X$KXFPYS - S[YS]tem Statistics                                      
            X$KXFPDP - [D]etached [P]rocess (slave) statistics                  
            X$KXFQSROW - Table [Q]ueue Statistics - 7.3.2 or higher             
          [C]oordinator Component                                               
            X$KXFPCST - Query [ST]atistics                                      
            X$KXFPCMS - [M]essage [S]tatistics                                  
            X$KXFPCDS - [D]equeue [S]tatistics                                  
          [S]lave Component                                                     
            X$KXFPSST - Query [ST]atistics                                      
            X$KXFPSMS - [M]essage [S]tatistics                                  
            X$KXFPCDS - [D]equeue [S]tatistics                                  

      [S]hared Cursor                                                           
        X$KXSBD - [B]ind [D]ata - 7.3.2 and above                               
        X$KXSCC - SQL [C]ursor [C]ache Data - 7.3.2 and above                   

  [N]etwork Layer - 7.0.15 or higher                                            
    Network [CO]nnections                                                       
      X$UGANCO - Current [N]etwork [CO]nnections

--------------------------------------------------------------------------------
 
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Quelques remarques sur cette liste

Cette liste date d'il y a vingt ans, elle doit donc être manipulée avec une grande précaution.

Par exemple, dans la liste ci-dessus la structure X$BH est décrite comme "Hash Table" alors que pour la 12c V$BH, s'appuyant sur X$BH, est la vue donnant accès aux Buffers Headers; on est donc loin du hash table. Néanmoins les codes utilisés pour nommer X$BH sont les suivants : B pour "[B]uffer Management" et H pour "Buffer [H]ash"; on est quand même bien dans la gestion des buffers, c'est le libellé "Hash table" qui me semble décalé.

A contrario la structure X$KQFCO "Table [CO]lumn definitions" existe encore dans la version 12c si on se base sur la liste de Daniel MORGAN même si son rôle n'est pas donné. Hé bien, c'est une excellente occasion de faire un test!!!!!

D'après la liste de 1999 son nom se décompose comme suit :
     [K]ernel Layer
          [Q]uery Layer
               [F]ixed Tables/views Management
                    [CO]lumn definitions
Visiblement elle sert à manager les tables, et plus précisément leurs colonnes, ce qui est raccord avec son rôle "[CO]lumn definitions".

          SQL> desc X$KQFCO
          Nom                     NULL ?           Type
          ----------------------------------------- -------- ----------------------------
          ADDR                                         RAW(8)
          INDX                                         NUMBER
          INST_ID                                     NUMBER
          KQFCOTAB                               NUMBER
          KQFCOTOB                               NUMBER
          KQFCOCNO                              NUMBER
          KQFCONAM                              VARCHAR2(30)
          KQFCODTY                               NUMBER
          KQFCOTYP                               NUMBER
          KQFCOMAX                               NUMBER
          KQFCOLSZ                               NUMBER
          KQFCOLOF                               NUMBER
          KQFCOSIZ                               NUMBER
          KQFCOOFF                              NUMBER
          KQFCOIDX                               NUMBER
          KQFCOIPO                              NUMBER

On remarque de suite que la colonne KQFCONAM est la seule de type VARCHAR2 et, surtout, qu'elle est de longueur 30! J'en déduis que c'est l'attribut pour le nom des colonnes car ce nom est limité à 30 caractères sous Oracle. En outre son libellé est explicit : CONAM signifie COlumn NAMe.
Avec le SELECT suivant, on confirme que cette structure mémoire gère bien les colonnes.
          SQL> select KQFCONAM, count(*) from X$KQFCO group by KQFCONAM having count(*) > 1 order by count(*);
          KQFCONAM                COUNT(*)
          ------------------------------ -------------------
          ...
         
OBJ#                                  24
          VALUE                               25
          INCIDENT_ID                      32
          PROBLEM_ID                     34
          TYPE                                 34
          STATUS                             37
          NAME                                64
          ADR_HOME                       83
          ADR_PATH_IDX                  83
          FLAGS                             108
          INST_ID                            909

          INDX                                 909
          ADDR                               909
          981 ligne(s) sélectionnée(s).         


Faisons un autre test avec X$KCCFN dont le nom se décompose comme suit :  
          [K]ernel Layer
                    [C]ache Layer
                              [C]ontrol File Management
                                        [F]ile [N]ames 

Est-ce que cette structure gère bien les noms des fichiers de la base?
Hé bien oui, le SELECT ci-dessous le prouve.
          SQL> desc X$KCCFN;
          Nom                     NULL ?           Type
          ------------------------------------------------------------------
          ADDR                                         RAW(8)
          INDX                                           NUMBER
          INST_ID                                      NUMBER
          FNNUM                                      NUMBER
          FNTYP                                        NUMBER
          FNFNO                                       NUMBER
          FNFWD                                      NUMBER
          FNBWD                                      NUMBER
          FNFLG                                       NUMBER
          FNNAM                                      VARCHAR2(513)
          FNONM                                      VARCHAR2(513)
          FNBOF                                       NUMBER
          FNUNN                                       NUMBER
          BYTES                                       NUMBER

          SQL> select FNNAM from X$KCCFN order by 1;
          FNNAM

          ------------------------------------------------------------------------------------------------------------------------------------------------
          F:\APP\YUKIO\ORADATA\TEST01\REDO01.LOG
          F:\APP\YUKIO\ORADATA\TEST01\REDO02.LOG
          F:\APP\YUKIO\ORADATA\TEST01\REDO03.LOG
          F:\APP\YUKIO\ORADATA\TEST01\SYSAUX01.DBF
          F:\APP\YUKIO\ORADATA\TEST01\SYSTEM01.DBF
          F:\APP\YUKIO\ORADATA\TEST01\TEMP01.DBF
          F:\APP\YUKIO\ORADATA\TEST01\UNDOTBS01.DBF
          F:\APP\YUKIO\ORADATA\TEST01\USERS01.DBF         
          8 ligne(s) sélectionnée(s).


Au vu de ces tests on peut donc déduire que la liste de 1995 est encore utilisable pour déconstruire le nom des structures mémoires d'Oracle et deviner leur utilité, même pour les structures non répertoriées dans cette vieille liste!