Lionel Frachon - SII Page 1 Statspack Analyse des statistiques générées.

Lionel Frachon - SII

Statspack

Analyse des statistiques générées


Génération d’un report (rappel)

Après avoir pris les photos (« snapshots »), il suffit de lancer la procédure (sous l’utilisateur concerné):

/oracle/ora920/rdbms/admin/spreport.sql

Paramètres : numéros de photos debut et fin, et nom de fichier


Statistiques inutiles

• Certaines statistiques dont les chiffres sont impressionnants n’ont aucun rapport avec une quelconque perte de performance.

• Ceci inclut notamment les timers (smon timer, pmon timer), les stats « SQL*Net », les stats rdbms …


Partie 1 : Informations relatives aux snapshots

STATSPACK report for

DB Name DB Id Instance Inst Num Release Cluster Host

------------ ----------- ------------ -------- ----------- ------- ------------

SILODECL 387227106 SILODECL 1 9.2.0.4.0 NO servdon1

Snap Id Snap Time Sessions Curs/Sess Comment

------- ------------------ -------- --------- -------------------

Begin Snap: 5 16-Mar-04 15:34:01 11 2.2

End Snap: 9 16-Mar-04 15:59:46 25 1.0

Elapsed: 25.75 (mins)


Partie 2 : Informations relatives à l’instance (mémoires & accès)

Cache Sizes (end)~~~~~~~~~~~~~~~~~ Buffer Cache: 64M Std Block Size: 8K Shared Pool Size: 80M Log Buffer: 512K

Load Profile~~~~~~~~~~~~ Per Second Per Transaction --------------- --------------- Redo size: 1,433.53 276,850.00 Logical reads: 4,628.45 893,868.75 Block changes: 2.57 497.25 Physical reads: 19.23 3,713.38 Physical writes: 1.91 368.13 User calls: 12.06 2,328.50 Parses: 1.11 214.25 Hard parses: 0.41 79.75 Sorts: 1.66 320.25 Logons: 0.03 5.13 Executes: 1.11 214.75 Transactions: 0.01

% Blocks changed per Read: 0.06 Recursive Call %: 12.50 Rollback per transaction %: 0.00 Rows per Sort: 391.75


Partie 3 : Efficacité de l’instance

Instance Efficiency Percentages (Target 100%)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Buffer Nowait %: 99.99 (> 90%) Redo NoWait %: 100.00 (>98%)

Buffer Hit %: 99.62 (> 90%) In-memory Sort %: 99.41(>99%)

Library Hit %: 95.57 (> 95%) Soft Parse %: 62.78 (>80%)

Execute to Parse %: 0.23 (> 98%) Latch Hit %: 99.26 (>99%)

Parse CPU to Parse Elapsd %: 52.44 (> 95%) % Non-Parse CPU: 41.55

Shared Pool Statistics Begin End

------ ------

Memory Usage %: 81.57 94.27 ( devrait etre stable)

% SQL with executions>1: 71.59 14.25 ( devrait etre proche de 100% si…)

% Memory for SQL w/exec>1: 47.00 8.33 ( ‘’ ‘’ ‘’ ‘’)


Partie 4 : Top 5 des evenements générant de l’activité sur la base

Top 5 Timed Events~~~~~~~~~~~~~~~~~~ % TotalEvent Waits Time (s) Ela Time-------------------------------------------- ------------ ----------- --------CPU time 171 41.03db file sequential read 26,969 165 39.64library cache pin 31 47 11.23resmgr:waiting in end wait 333 22 5.40latch free 2,041 3 .80


Partie 5 : Événements d’attenteWait Events for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> s - second-> cs - centisecond - 100th of a second-> ms - millisecond - 1000th of a second-> us - microsecond - 1000000th of a second-> ordered by wait time desc, waits desc (idle events last)

Avg Total Wait wait WaitsEvent Waits Timeouts Time (s) (ms) /txn---------------------------- ------------ ---------- ---------- ------ --------db file sequential read 26,969 0 165 6 3,371.1library cache pin 31 15 47 1507 3.9resmgr:waiting in end wait 333 0 22 67 41.6latch free 2,041 0 3 2 255.1buffer busy waits 565 0 3 6 70.6resmgr:waiting in check 46 0 2 39 5.8control file parallel write 501 0 1 2 62.6resmgr:waiting in check2 20 0 1 40 2.5SQL*Net more data to client 5,942 0 0 0 742.8log file parallel write 43 0 0 5 5.4log file sync 17 0 0 6 2.1db file scattered read 13 0 0 2 1.6control file sequential read 630 0 0 0 78.8resmgr:wait in actses run 1 0 0 5 0.1direct path read 164 0 0 0 20.5direct path write 30 0 0 0 3.8SQL*Net message from client 18,643 0 46,422 2490 2,330.4SQL*Net more data from clien 231 0 8 36 28.9SQL*Net message to client 18,657 0 0 0 2,332.1 -------------------------------------------------------------2,041 3 .80

On recherche ici les plus grosses attentes (waits & avg wait), ce sont celles qui handicapent le plus la base, car Oracle attend que ces événements soient passés afin de pouvoir enchaîner sur le traitement suivant.


Partie 6 : Événements d’attente (background)

Background Wait Events for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> ordered by wait time desc, waits desc (idle events last)

Avg Total Wait wait WaitsEvent Waits Timeouts Time (s) (ms) /txn---------------------------- ------------ ---------- ---------- ------ --------control file parallel write 501 0 1 2 62.6log file parallel write 43 0 0 5 5.4db file scattered read 9 0 0 3 1.1db file sequential read 5 0 0 3 0.6control file sequential read 350 0 0 0 43.8rdbms ipc reply 8 0 0 0 1.0rdbms ipc reply 8 0 0 0 1.0rdbms ipc message 1,590 1,535 7,526 4733 198.8rdbms ipc message 1,590 1,535 7,526 4733 198.8smon timer 6 4 1,535 ###### 0.8smon timer 6 4 1,535 ###### 0.8pmon timer 519 519 1,509 2907 64.9pmon timer 519 519 1,509 2907 64.9 -------------------------------------------------------------


Partie 7 : Requetes les plus consommatrices (part 1)

SQL ordered by Gets SQL ordered by Gets for DB: SILODECL Instance: SILODECL Snaps: 5 -9

-> End Buffer Gets Threshold: 10000-> Note that resources reported for PL/SQL includes the resources used by all SQL statements called within the PL/SQL code. As individual SQL statements are also reported, it is possible and valid for the summed total % to exceed 100

CPU Elapsd Buffer Gets Executions Gets per Exec %Total Time (s) Time (s) Hash Value--------------- ------------ -------------- ------ -------- --------- ----- 6,721,520 633 10,618.5 94.0 52.21 210.53 1358576331Module: JDBC Thin Clientselect /*+ INDEX (DONNEE_TVA IX_DONNEE_TVA_03) INDEX (IMPRIME_TVA IX_IMPRIME_TVA_03) */ T.ID_DEPOT_TVA, T.siren, T.nic, T.numact, T.numseq, T.numero_ordre, T.sages2_recette, T.sages2_cdi, T.type_declaration, to_char(T.dls,'DD/MM/YYYY') as dls, to_char(T.date_depot,'DD/MM/YYYY') as date_depot, to_char(T.date_debut_perio

93,779 4 23,444.8 1.3 6.44 7.05 300097093Module: SQL*Plusbegin :numero_snapshot := statspack.snap(i_snap_level=>7); end;

Attention, 500 premiers caracteres, voir hashvalue



SQL ordered by Reads for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> End Disk Reads Threshold: 1000

CPU Elapsd Physical Reads Executions Reads per Exec %Total Time (s) Time (s) Hash Value--------------- ------------ -------------- ------ -------- --------- ---------- 22,042 633 34.8 74.2 52.21 210.53 1358576331Module: JDBC Thin Clientselect /*+ INDEX (DONNEE_TVA IX_DONNEE_TVA_03) INDEX (IMPRIME_TVA IX_IMPRIME_TVA_03) */ T.ID_DEPOT_TVA, T.siren, T.nic, T.numact, T.numseq, T.numero_ordre, T.sages2_recette, T.sages2_cdi, T.type_declaration, to_char(T.dls,'DD/MM/YYYY') as dls, to_char(T.date_depot,'DD/MM/YYYY') as date_depot, to_char(T.date_debut_perio

1,902 4 475.5 6.4 6.44 7.05 300097093Module: SQL*Plusbegin :numero_snapshot := statspack.snap(i_snap_level=>7); end;



SQL ordered by ExecutionsSQL ordered by Executions for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> End Executions Threshold: 100

CPU per Elap per Executions Rows Processed Rows per Exec Exec (s) Exec (s) Hash Value------------ --------------- ---------------- ----------- ---------- ---------- 633 4,531 7.2 0.08 0.33 1358576331Module: JDBC Thin Clientselect /*+ INDEX (DONNEE_TVA IX_DONNEE_TVA_03) INDEX (IMPRIME_TVA IX_IMPRIME_TVA_03) */ T.ID_DEPOT_TVA, T.siren, T.nic, T.numact, T.numseq, T.numero_ordre, T.sages2_recette, T.sages2_cdi, T.type_declaration, to_char(T.dls,'DD/MM/YYYY') as dls, to_char(T.date_depot,'DD/MM/YYYY') as date_depot, to_char(T.date_debut_perio



SQL ordered by Parse CallsSQL ordered by Parse Calls for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> End Parse Calls Threshold: 1000

% Total Parse Calls Executions Parses Hash Value------------ ------------ -------- ---------- 633 633 36.93 1358576331Module: JDBC Thin Clientselect /*+ INDEX (DONNEE_TVA IX_DONNEE_TVA_03) INDEX (IMPRIME_TVA IX_IMPRIME_TVA_03) */ T.ID_DEPOT_TVA, T.siren, T.nic, T.numact, T.numseq, T.numero_ordre, T.sages2_recette, T.sages2_cdi, T.type_declaration, to_char(T.dls,'DD/MM/YYYY') as dls, to_char(T.date_depot,'DD/MM/YYYY') as date_depot, to_char(T.date_debut_perio


Partie 8 : Activité de l’instanceInstance Activity StatsInstance Activity Stats for DB: SILODECL Instance: SILODECL Snaps: 5 -9

Statistic Total per Second per Trans--------------------------------- ------------------ -------------- ------------active txn count during cleanout 85 0.1 10.6background timeouts 1,534 1.0 191.8buffer is not pinned count 2,912,871 1,885.4 364,108.9buffer is pinned count 2,101,500 1,360.2 262,687.5bytes received via SQL*Net from c 7,057,529 4,568.0 882,191.1bytes sent via SQL*Net to client 22,618,423 14,639.8 2,827,302.9calls to get snapshot scn: kcmgss 1,978 1.3 247.3[…]commit cleanouts successfully com 406 0.3 50.8commit txn count during cleanout 258 0.2 32.3consistent changes 159 0.1 19.9consistent gets 7,147,193 4,626.0 893,399.1CPU used by this session 17,072 11.1 2,134.0CPU used when call started 17,072 11.1 2,134.0[…]transaction rollbacks 8 0.0 1.0

Ici on peut détailler chaque action de la base, mais ceci ne sert qu’a confirmer le pré-diagnostic déjà établi,Explications completes sur Oracle9i Database Reference Release 2 (9.2)


Partie 8 : Activité de l’instanceActivité significative :

Activité des buffersbuffer is not pinned count 2,912,871 1,885.4 364,108.9 => buffers libresbuffer is pinned count 2,101,500 1,360.2 262,687.5 => buffers occupés (=> déplacement

des blocs en mémoire)no buffer to keep pinned count 2,805,800 1,816.1 350,725.0 => buffers alloués mais non

disponiblesno work - consistent read gets 2,469,792 1,598.6 308,724.0 => buffers ok (ni cleanout, ni

rollback)

Activité des I/Oindex fetch by key 296,170 191.7 37,021.3 => acces table index par clef (le +

efficace)index scans kdiixs1 2,946,260 1,907.0 368,282.5 => acces par “index fast full scan”table fetch by rowid 1,182,762 765.5 147,845.3 => acces table via index : optimisétable fetch continued row 2,138 1.4 267.3 => multiples I/O pour acceder un

bloc, du a un bloc trop grand ou chaîné

table scan blocks gotten 320 0.2 40.0 => besoin reel des select en blocstable scan rows gotten 2,946 1.9 368.3=> besoin reel des select en lignestable scans (long tables) 0 0.0 0.0 => scans sur grandes tablestable scans (short tables) 47 0.0 5.9 => scans sur petites tables

Trissorts (disk) 15 0.0 1.9 => tris disquesorts (memory) 2,547 1.7 318.4 => tris memoiresorts (rows) 1,003,672 649.6 125,459.0 => nb de lignes triées

Autrestransaction rollbacks 8 0.0 1.0


Partie 9 : Activité des I/O (plusieurs tris)

File IO Stats for DBFile IO Stats for DB: SILODECL Instance: SILODECL Snaps: 5 -9->ordered by Tablespace, File

Tablespace Filename------------------------ ---------------------------------------------------- Av Av Av Av Buffer Av Buf Reads Reads/s Rd(ms) Blks/Rd Writes Writes/s Waits Wt(ms)-------------- ------- ------ ------- ------------ -------- ---------- ------

SILODECL_D06 /ADE-DECLA1-DATA/silodecl_d06.dbf 114 0 6.3 1.0 0 0 2 5.0





[…]SILODECL_D16 /ADE-DECLA1-DATA/silodecl_d16.dbf 3,898 3 6.8 1.0 0 0 99 5.2

SILODECL_D17 /ADE-DECLA1-DATA/silodecl_d17.dbf 2,999 2 6.5 1.0 0 0 84 4.8

SILODECL_I05 /ADE-DECLA1-INDEX/silodecl_i05.dbf 64 0 6.6 1.0 0 0 0

SILODECL_I06 /ADE-DECLA1-INDEX/silodecl_i06.dbf 313 0 6.3 1.0 0 0 1 10.0

On recherche ici les différences de traitement (I/O) entre les différents tablespaces plutôt que des valeurs optimales, ainsi que le « buffer wait » moyen qui donne une idée de l’encombrement des I/O a partir du disque


Partie 10 : Buffer poolBuffer Pool StatisticsBuffer Pool Statistics for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> Standard block size Pools D: default, K: keep, R: recycle-> Default Pools for other block sizes: 2k, 4k, 8k, 16k, 32k

Free Write Buffer Number of Cache Buffer Physical Physical Buffer Complete BusyP Buffers Hit % Gets Reads Writes Waits Waits Waits--- ---------- ----- ----------- ----------- ---------- ------- -------- ------D 7,940 99.6 7,150,839 27,043 273 0 0 724 -------------------------------------------------------------

Cette statistique donne le ratio entre la recherche de blocs de données trouvés en cache sur le nombre total de blocs requis par l’ensemble des requêtes SQL. Un taux < à 95% indique que le buffer est trop petit, exceptionnellement que de multiples activités se passent simultanément sur la base (tres tres rare).


Partie 11 : Conseiller Buffer poolBuffer Pool AdvisoryBuffer Pool Advisory-> Only rows with estimated physical reads >0 are displayed-> ordered by Block Size, Buffers For Estimate

Size for Size Buffers for Est Physical EstimatedP Estimate (M) Factr Estimate Read Factor Physical Reads--- ------------ ----- ---------------- ------------- ------------------D 16 .3 1,985 1.01 6,993,287D 32 .5 3,970 1.01 6,959,843D 48 .8 5,955 1.00 6,942,127D 64 1.0 7,940 1.00 6,923,121D 80 1.3 9,925 1.00 6,914,350D 96 1.5 11,910 1.00 6,897,016D 112 1.8 13,895 0.99 6,877,294D 128 2.0 15,880 0.99 6,858,941D 144 2.3 17,865 0.99 6,848,817D 160 2.5 19,850 0.99 6,830,846D 176 2.8 21,835 0.99 6,827,869D 192 3.0 23,820 0.99 6,822,871D 208 3.3 25,805 0.98 6,817,586D 224 3.5 27,790 0.98 6,810,837D 240 3.8 29,775 0.98 6,800,825D 256 4.0 31,760 0.98 6,792,006D 272 4.3 33,745 0.98 6,780,609D 288 4.5 35,730 0.98 6,759,884D 304 4.8 37,715 0.97 6,745,256D 320 5.0 39,700 0.97 6,715,919 -------------------------------------------------------------

Advisory = conseiller

Cette partie simule une diminution/augmentationdu buffer pool afin de vérifier le gain ou l’impact de la taille mémoire buffer sur le nombre de lectures nécessaires

Rappel : il existe les vue v$shared_pool_advice et v$buffer_pool_advice qui fournissent les mêmes données en temps réel.


Partie 12 : Attentes du Buffer PoolBuffer wait Statistics Buffer wait Statistics for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> ordered by wait time desc, waits desc

Tot Wait AvgClass Waits Time (s) Time (ms)------------------ ----------- ---------- ---------data block 723 3 5undo header 1 0 0-------------------------------------------------------------

Attente majoritairement dûe aux blocs de données


Partie 13 : Rollbacks & undoRollback Segment Stats : Inutilisé en 9i

Remplacé par :

Undo Segment SummaryUndo Segment Summary for DB: SILODECL Instance: SILODECL Snaps: 5 -9

-> Undo segment block stats:-> uS - unexpired Stolen, uR - unexpired Released, uU - unexpired reUsed-> eS - expired Stolen, eR - expired Released, eU - expired reUsed

Undo Undo Num Max Qry Max Tx Snapshot Out of uS/uR/uU/ TS# Blocks Trans Len (s) Concurcy Too Old Space eS/eR/eU---- -------------- ---------- -------- ---------- -------- ------

------------- 1 153 11,558 5 2 0 0 0/0/0/0/0/0 -------------------------------------------------------------

Undo Segment Stats for DB: SILODECL Instance: SILODECL Snaps: 5 -9-> ordered by Time desc

Undo Num Max Qry Max Tx Snap Out of uS/uR/uU/End Time Blocks Trans Len (s) Concy Too Old Space eS/eR/eU------------ ------------ -------- ------- -------- ------- ------

-------------16-Mar 15:56 29 3,872 2 2 0 0 0/0/0/0/0/016-Mar 15:46 40 3,853 4 1 0 0 0/0/0/0/0/016-Mar 15:36 84 3,833 5 1 0 0 0/0/0/0/0/0 -------------------------------------------------------------

Lionel Frachon - SII Page 1 Statspack Analyse des statistiques générées.

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Transcript of Lionel Frachon - SII Page 1 Statspack Analyse des statistiques générées.