Catégorie : Support Niveau 3

Exploitation, SQL, Support Niveau 3

Stored outlines

Pour voir quelle catégorie d’outlines est utilisée au niveau instance il suffit de suivre La note metalink (internal only, you don’t have access) ou de retrouver ses diverses transcription oveurzeunaitte comme par exemple sur le site Oracle Guy ou le blog El Caro histoire de rester sur Blogger.

Donc que est l’intérêt de ce post ??? Le français de France allons, pour les dba qui se vrillent l’œil dès que la Perfide Albion vient envahir leur champ de vision

Alors comment qu’on fait Madame ?

Simplissime, on sort le code hexa d’une partie de la SGA (ou de l’UGA si des fois on fait ça au niveau session) L’enfance de l’art non ?

Les Instructions qui vont bien : 

SQL> oradebug setmypid
SQL> oradebug dumpvar sga sgauso

les résultats sont pour le moins cocaces

qolprm sgauso_ [20014F44, 20014F68) = 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000

Qui signifie : “FALSE” … Oui c’est pas forcément évident

qolprm sgauso_ [8001304C, 80013070) = 00000001 00074445 4641554C 54000000 ...

Qui signifie : “DEFAULT” … Sachant que DEFAULT fait 7 lettres et qu’en hexadécimal DEFAULT s’écrit 4445 4641554c 54, on commence à comprendre, on la refait doucement :

qolprm sgauso_ [8001304C, 80013070) = 00000001 00074445 4641554C 54000000 ... 
                                                 7 D E  F A U L  T

OK ?

Exploitation, SQL, Support Niveau 2, Support Niveau 3

Paramètres internes de l’instance

La table x$kvit donne une liste de paramètres dynamiques utilisés au moment du select.

La version 10g remonte la liste suivante :

select KVITTAG
        , KVITDSC
        , KVITVAL
from x$kvit
/

KVITTAG              KVITDSC                                                             KVITVAL
-------------------- ---------------------------------------------------------------- ----------
ksbcpu               number of logical CPUs in the system used by Oracle                       2
ksbcpucore           number of physical CPU cores in the system used by Oracle                 0
ksbcpusocket         number of physical CPU sockets in the system used by Oracle               0
ksbcpu_hwm           high water mark of number of CPUs used by Oracle                          2
ksbcpucore_hwm       high water mark of number of CPU cores on system                          0
ksbcpusocket_hwm     high water mark of number of CPU sockets on system                        0
ksbcpu_actual        number of available CPUs in the system                                    2
ksbcpu_dr            CPU dynamic reconfiguration supported                                     1
kcbnbh               number of buffers                                                    136551
kcbldq               large dirty queue if kcbclw reaches this                                 25
kcbfsp               Max percentage of LRU list foreground can scan for free                  40
kcbcln               Initial percentage of LRU list to keep clean                              2
kcbnbf               number buffer objects                                                   750
kcbwst               Flag that indicates recovery or db suspension                             0
kcteln               Error Log Number for thread open                                          0
kcvgcw               SGA: opcode for checkpoint cross-instance call                            0
kcvgcw               SGA:opcode for pq checkpoint cross-instance call                          0

La version 9i remonte la liste suivante :


KVITTAG              KVITDSC                                                             KVITVAL
-------------------- ---------------------------------------------------------------- ----------
kcbnbh               number of buffers                                                    381120
kcbldq               large dirty queue if kcbclw reaches this                                 25
kcbdsp               Max percentage of LRU list dbwriter can scan for dirty                   25
kcbfsp               Max percentage of LRU list foreground can scan for free                  40
kcbnbf               number buffer objects                                                  5000
kcbwst               Flag that indicates recovery or db suspension                             0
kcteln               Error Log Number for thread open                                          0
kcvgcw               SGA: opcode for checkpoint cross-instance call                            0
Exploitation, Métrologie, SQL, Support Niveau 2, Support Niveau 3

Incidence du statistics level

La variable statistics level permet des stocker des statistiques dans certaines vues.

La requête suivante permet de voir quelle vue est impactée, à quel niveau de statistique et si le calcul de la statistique peut être modifié au niveau session

select decode(ACTIVATION_LEVEL,1,'Typical','All') "A Level"
  , Name
  , decode(SESSION_CHANGEABLE,1,'Ok',' -') "Modif"
  , decode(SESSION_STATUS,1,'On',' -') "Sess"
  , decode(SYSTEM_STATUS,1,'On',' -') "Sys"
  , VIEW_NAME
from x$prmsltyx
order by ACTIVATION_LEVEL
/

En 11gR2 on obtient 

A Level NAME                                                             Mo Se Sy VIEW_NAME
------- ---------------------------------------------------------------- -- -- -- -------------------------
Typical Buffer Cache Advice                                               - On On V$DB_CACHE_ADVICE
Typical V$IOSTAT_* statistics                                             - On On
Typical Timed Statistics                                                 Ok On On
Typical MTTR Advice                                                       - On On V$MTTR_TARGET_ADVICE
Typical Adaptive Thresholds Enabled                                       - On On
Typical Segment Level Statistics                                          - On On V$SEGSTAT
Typical PGA Advice                                                        - On On V$PGA_TARGET_ADVICE
Typical Shared Pool Advice                                                - On On V$SHARED_POOL_ADVICE
Typical Modification Monitoring                                           - On On
Typical Longops Statistics                                                - On On V$SESSION_LONGOPS
Typical Bind Data Capture                                                 - On On V$SQL_BIND_CAPTURE
Typical Ultrafast Latch Statistics                                        - On On
Typical Threshold-based Alerts                                            - On On
Typical Global Cache Statistics                                           - On On
Typical Active Session History                                            - On On V$ACTIVE_SESSION_HISTORY
Typical Undo Advisor, Alerts and Fast Ramp up                             - On On V$UNDOSTAT
Typical Streams Pool Advice                                               - On On V$STREAMS_POOL_ADVICE
Typical Time Model Events                                                Ok On On V$SESS_TIME_MODEL
Typical Plan Execution Sampling                                          Ok On On V$ACTIVE_SESSION_HISTORY
Typical Automated Maintenance Tasks                                       - On On
Typical SQL Monitoring                                                   Ok On On V$SQL_MONITORING
All     Plan Execution Statistics                                        Ok  -  - V$SQL_PLAN_STATISTICS
All     Timed OS Statistics                                              Ok  -  -

En 10g on obtient 

A Level NAME                                     Mo Se Sy VIEW_NAME
------- ---------------------------------------- -- -- -- ------------------------------
Typical Buffer Cache Advice                       - On On V$DB_CACHE_ADVICE
Typical Streams Pool Advice                       - On On V$STREAMS_POOL_ADVICE
Typical Timed Statistics                         Ok On On
Typical MTTR Advice                               - On On V$MTTR_TARGET_ADVICE
Typical Undo Advisor, Alerts and Fast Ramp up     - On On V$UNDOSTAT
Typical Segment Level Statistics                  - On On V$SEGSTAT
Typical PGA Advice                                - On On V$PGA_TARGET_ADVICE
Typical Shared Pool Advice                        - On On V$SHARED_POOL_ADVICE
Typical Modification Monitoring                   - On On
Typical Longops Statistics                        - On On V$SESSION_LONGOPS
Typical Bind Data Capture                         - On On V$SQL_BIND_CAPTURE
Typical Ultrafast Latch Statistics                - On On
Typical Threshold-based Alerts                    - On On
Typical Global Cache Statistics                   - On On
Typical Active Session History                    - On On V$ACTIVE_SESSION_HISTORY
All     Plan Execution Statistics                Ok  -  - V$SQL_PLAN_STATISTICS
All     Timed OS Statistics                      Ok  -  -

En 9i on obtient 

A Level NAME                           Mo Se Sy VIEW_NAME
------- ------------------------------ -- -- -- ------------------------------
Typical Buffer Cache Advice             - On On V$DB_CACHE_ADVICE
Typical MTTR Advice                     - On On V$MTTR_TARGET_ADVICE
Typical Timed Statistics               Ok On On
Typical PGA Advice                      - On On V$PGA_TARGET_ADVICE
Typical Shared Pool Advice              - On On V$SHARED_POOL_ADVICE
Typical Segment Level Statistics        - On On V$SEGSTAT
All     Timed OS Statistics            Ok  -  -
All     Plan Execution Statistics      Ok  -  - V$SQL_PLAN_STATISTICS
Exploitation, Support Niveau 3, Tuning

Afficher la liste des “fix control” passés sur une base

Les fix control sont apportés par les patchs / patchsets / patchsets updates et influent sur le comportement de l’optimiseur. La table x$qksbgsys les liste et donne leur description succincte

La requête suivante liste les bugs, ce qu’ils font et la version à partir de laquelle ils ont étés introduits

select BUGNO_QKSBGSYROW
  , DESC_QKSBGSYROW
  , OFE_QKSBGSYROW
  , EVENT_QKSBGSYROW
from x$qksbgsys
/

BUGNO_QKSBGSYROW DESC_QKSBGSYROW                                                  OFE_QKSBGSYROW            EVENT_QKSBGSYROW
---------------- ---------------------------------------------------------------- ------------------------- ----------------
        4611850 do not clobber predicate during first-k row estimate phase       10.2.0.2                                 0
        4663804 use smallest table as first table in join card. initial ordering 10.2.0.2                                 0
        4663698 for cached NL table set tab_cost_io to zero                      10.2.0.2                                 0
[...]

La requete suivante sur la table x$qksbgses est équivalente

select distinct BUGNO_QKSBGSEROW
   , DESC_QKSBGSEROW
   , OFE_QKSBGSEROW
   , EVENT_QKSBGSEROW
from x$qksbgses
/

Il est possible de désactiver un des correctifs par hint :

select /*+ OPT_PARAM('_fix_control' '9195582:0') */ * from dual ;

Depuis quelques version les vues V$SYS_FIX_CONTROL et V$SESSION_FIX_CONTROL permettent de voir ces données plus facilement

desc V$SESSION_FIX_CONTROL
 Name                             Null?    Type
 -------------------------------- -------- ----------------------
 SESSION_ID                                NUMBER
 BUGNO                                     NUMBER
 VALUE                                     NUMBER
 SQL_FEATURE                               VARCHAR2(64)
 DESCRIPTION                               VARCHAR2(64)
 OPTIMIZER_FEATURE_ENABLE                  VARCHAR2(25)
 EVENT                                     NUMBER
 IS_DEFAULT                                NUMBER

desc V$SYSTEM_FIX_CONTROL
 Name                             Null?    Type
 -------------------------------- -------- ----------------------
 BUGNO                                     NUMBER
 VALUE                                     NUMBER
 SQL_FEATURE                               VARCHAR2(64)
 DESCRIPTION                               VARCHAR2(64)
 OPTIMIZER_FEATURE_ENABLE                  VARCHAR2(25)
 EVENT                                     NUMBER
 IS_DEFAULT                                NUMBER
Développement, Exploitation, SQL, Support Niveau 3

Lister les tables X$ d’une version Oracle

Ce petit script PERL permet de lister les tables “X$” du moteur … Ce qui ne dit pas ce qu’elles font

#!/usr/bin/perl -w

use strict;

#open O, ($ORACLE_HOME."/bin/oracle");
open O, ("/logiciels/oracle/ora_10.2.0/bin/oracle");
open F, (">x");

my $l;
my $p = ' ' x 40;
my %x;

while (read (O,$l,10000)) {
  $l = $p.$l;

  foreach ($l =~ /(x$w{3,})/g) {
   $x{$_}++;
  }

  $p = substr ($l,-40);
}

foreach (sort keys %x) {
  print F "$_n";
}

Ce script provient du site http://www.adp-gmbh.ch

On peut trouver certaines explications sur le contenu des tables “X$” sur freeshell, sur le site BC Oracle Training ou en bien d’autres endroits 😉

La version 10 d’oracle en liste quelques 350 par exemple la table x$kwddef liste l’ensemble des mots clés du SQL, la requête suivante permet donc de les lister :

select KEYWORD from x$kwddef
order by KEYWORD
/
Support Niveau 3

vipca -silent

Créer les adresses vip en utilisant vipca en mode silencieux :

En étant connecté root :

vipca -silent -nodelist rac01,rac02 -nodevips 'rac01/rac01-vip/255.255.255.0/ce1,rac02/rac02-vip/255.255.255.0/ce1'

Gérer le failover des VIP :

crs_stat -p ora.rac01.vip > /var/tmp/ora.rac01.vip.cap
crs_stat -p ora.rac02.vip > /var/tmp/ora.rac02.vip.cap

changer les lignes

HOSTING_MEMBERS=rac01

en

HOSTING_MEMBERS=rac01 rac02

crs_register ora.rac01.vip -dir /var/tmp -u
crs_register ora.rac02.vip -dir /var/tmp -u