Re: library cache pin wait

Increase shared pool.

VIVEK_SHARMA wrote:
>
> For a Hybrid Banking Application , following waits are Observed :-
> Oracle ver 9.2 (Dedicated Server connections)
> Solaris 8
> M/c SF15K
> Application mostly uses Static Queries (i.e. with Bind variables) ,
> though there may be some amount of Literal SQLs too
> DB Size = 250 GB
>
> Qs How may the following waits be approached ?
> Qs Since we have just moved to 9.2 , any advisable standard init.ora parameters with 9.2 ?
> Qs Should CURSOR_SHARING = FORCE or SIMILAR be considered ? Which is better
> & what may be the Overhead of these on production ?
>
> Shall answer any Clarifications .
>
> Thanks
>
> ------------------------------------------------------------------------------
> STATSPACK report for
>
> DB Name DB Id Instance Inst Num Release Cluster Host
> ------------ ----------- ------------ -------- ----------- ------- ------------
> TBASUN 1820705732 tbasun 1 9.2.0.3.0 NO IB15KDB
>
> Snap Id Snap Time Sessions Curs/Sess Comment
> ------- ------------------ -------- --------- -------------------
> Begin Snap: 71 03-Jun-03 12:00:05 2,953 53.2
> End Snap: 91 03-Jun-03 13:00:05 3,030 55.2
> Elapsed: 60.00 (mins)
>
> Cache Sizes (end)
> ~~~~~~~~~~~~~~~~~
> Buffer Cache: 703M Std Block Size: 8K
> Shared Pool Size: 400M Log Buffer: 6,144K
>
> Load Profile
> ~~~~~~~~~~~~ Per Second Per Transaction
> --------------- ---------------
> Redo size: 251,510.31 1,682.23
> Logical reads: 35,458.62 237.17
> Block changes: 1,226.80 8.21
> Physical reads: 2,391.08 15.99
> Physical writes: 155.51 1.04
> User calls: 8,556.91 57.23
> Parses: 495.46 3.31
> Hard parses: 71.17 0.48
> Sorts: 201.79 1.35
> Logons: 8.80 0.06
> Executes: 5,949.80 39.80
> Transactions: 149.51
>
> % Blocks changed per Read: 3.46 Recursive Call %: 43.86
> Rollback per transaction %: 55.51 Rows per Sort: 45.29
>
> Instance Efficiency Percentages (Target 100%)
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Buffer Nowait %: 99.98 Redo NoWait %: 99.99
> Buffer Hit %: 93.35 In-memory Sort %: 99.94
> Library Hit %: 98.14 Soft Parse %: 85.64
> Execute to Parse %: 91.67 Latch Hit %: 98.81
> Parse CPU to Parse Elapsd %: 3.56 % Non-Parse CPU: 90.92
>
> Shared Pool Statistics Begin End
> ------ ------
> Memory Usage %: 93.23 86.67
> % SQL with executions>1: 54.37 75.05
> % Memory for SQL w/exec>1: 47.47 70.06
>
> Top 5 Timed Events
> ~~~~~~~~~~~~~~~~~~ % Total
> Event Waits Time (s) Ela Time
> -------------------------------------------- ------------ ----------- --------
> library cache pin 97,608 95,845 40.95
> latch free 2,788,119 70,018 29.91
> CPU time 25,145 10.74
> library cache load lock 19,686 19,419 8.30
> db file sequential read 6,334,694 6,715 2.87
> -------------------------------------------------------------
>
> -------------------------------------------------------------
> Latch Activity for DB: TBASUN Instance: tbasun Snaps: 71 -91
> ->"Get Requests", "Pct Get Miss" and "Avg Slps/Miss" are statistics for
> willing-to-wait latch get requests
> ->"NoWait Requests", "Pct NoWait Miss" are for no-wait latch get requests
> ->"Pct Misses" for both should be very close to 0.0
>
> Pct Avg Wait Pct
> Get Get Slps Time NoWait NoWait
> Latch Requests Miss /Miss (s) Requests Miss
> ------------------------ -------------- ------ ------ ------ ------------ ------
> library cache 69,587,442 3.3 0.7 53315 663,932 50.5
> row cache objects 29,587,406 2.8 0.1 2549 128,096 18.3
>
> Library Cache Activity for DB: TBASUN Instance: tbasun Snaps: 71 -91
> ->"Pct Misses" should be very low
>
> Get Pct Pin Pct Invali-
> Namespace Requests Miss Requests Miss Reloads dations
> --------------- ------------ ------ -------------- ------ ---------- --------
> BODY 3,466 11.3 3,532 17.9 187 0
> CLUSTER 12,921 0.1 14,953 0.1 0 0
> INDEX 38,620 19.0 38,618 24.5 8 0
> SQL AREA 1,627,354 6.3 26,006,472 0.8 152,116 8
> TABLE/PROCEDURE 1,206,367 0.3 1,875,867 15.4 158,738 0
> TRIGGER 1,405 0.2 1,713 44.4 542 0
> -------------------------------------------------------------
>
> shared_pool_reserved_size 104857600
> shared_pool_size 419430400
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: VIVEK_SHARMA
> INET: VIVEK_SHARMA_at_infosys.com
>
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-- 
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-- 
Author: Anjo Kolk
  INET: anjo_at_oraperf.com

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