• 关于shared pool的深入探讨(一) 【转载】


    关于shared pool的深入探讨(一)

     
    关于shared pool的设置一直是一个争议较多的内容.
    很多文章上说,shared pool设置过大会带来额外的管理上的负担,从而在某些条件下会导致性能的下降.

    那么这个管理上的负担指的是什么内容呢?
    本文对这个内容作一定的深入探讨.
    本文只涉及一个方面,后续的文章将从其他方面继续讨论.

    基础知识:

    我们可以通过如下命令转储shared pool共享内存的内容:

    
    SQL> alter session set events 'immediate trace name heapdump level 2'; 

    Session altered.

    本测试中引用的两个trace文件:

    9i:

    SQL> @gettrcname

    TRACE_FILE_NAME
    --------------------------------------------------------------------------------
    /opt/oracle/admin/hsjf/udump/hsjf_ora_24983.trc

    8i:

    SQL> @gettrcname

    TRACE_FILE_NAME
    --------------------------------------------------------------------------------
    /usr/oracle8/admin/guess/udump/guess_ora_22038.trc

     

    Shared Pool通过free list管理free块,Free List按不同size划分Bucket
    在Oracle8i中,不同bucket的size范围如下所示(size显示的是下边界):

    oracle:/usr/oracle8/admin/guess/udump>cat guess_ora_22038.trc|grep Bucket
    Bucket 0 size=44 
    Bucket 1 size=76 
    Bucket 2 size=140
    Bucket 3 size=268
    Bucket 4 size=524
    Bucket 5 size=1036
    Bucket 6 size=2060
    Bucket 7 size=4108
    Bucket 8 size=8204
    Bucket 9 size=16396
    Bucket 10 size=32780



    我们注意,在这里,小于76的块都位于Bucket 0上;大于32780的块,都在Bucket 10上
    初始的,数据库启动以后,shared pool多数是连续内存块
    当空间分配使用以后,内存块开始被分割,碎片开始出现,Bucket列表开始变长

    Oracle请求shared pool空间时,首先进入相应的Bucket进行查找。
    如果找不到,则转向下一个非空的bucket,获取第一个chunk。
    分割这个chunk,剩余部分会进入相应的Bucket,进一步增加碎片。

    最终的结果是,Bucket 0上的内存块会越来越多,越来越碎小
    (在我这个测试的小型的数据库上,Bucket 0上的碎片已经达到9030个
    而shared_pool_size设置仅为150M)
    通常如果每个Bucket上的chunk多余2000个,就被认为是share pool碎片过多

    Shared Pool的碎片过多,是Shared pool产生性能问题的主要原因。
    碎片过多会导致Search Free List的时间过长,从而使shared pool latch被长时间持有,导致更多的Latch竞争。

    而在大多数情况下,我们请求的都是相对小的chunk,这样搜索Bucket 0往往消耗了大量的时间以及资源
    这可能导致share pool Latch被长时间的持有,导致更多的share pool竞争

    所以在Oracle9i之前,如果盲目的增大shared_pool_size或设置过大的shared_pool_size,往往会适得其反

    我们看一下Oracle9i中的处理方式:


    [oracle@jumper oracle]$ sqlplus "/ as sysdba"

    SQL*Plus: Release 9.2.0.3.0 - Production on Wed Aug 18 22:13:07 2004

    Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

    Connected to:
    Oracle9i Enterprise Edition Release 9.2.0.3.0 - Production
    With the Partitioning, OLAP and Oracle Data Mining options
    JServer Release 9.2.0.3.0 - Production

    SQL> alter session set events 'immediate trace name heapdump level 2';

    Session altered.

    SQL> @gettrcname

    TRACE_FILE_NAME
    --------------------------------------------------------------------------------
    /opt/oracle/admin/hsjf/udump/hsjf_ora_24983.trc

    SQL> 
    SQL> !
    [oracle@jumper oracle]$ cd $admin
    [oracle@jumper udump]$ cat hsjf_ora_24983.trc|grep Bucket
    Bucket 0 size=16
    Bucket 1 size=20
    Bucket 2 size=24
    Bucket 3 size=28
    Bucket 4 size=32
    Bucket 5 size=36
    Bucket 6 size=40
    Bucket 7 size=44
    Bucket 8 size=48
    Bucket 9 size=52
    Bucket 10 size=56
    Bucket 11 size=60
    Bucket 12 size=64
    Bucket 13 size=68
    Bucket 14 size=72
    Bucket 15 size=76
    Bucket 16 size=80
    Bucket 17 size=84
    Bucket 18 size=88
    Bucket 19 size=92
    Bucket 20 size=96
    Bucket 21 size=100
    Bucket 22 size=104
    Bucket 23 size=108
    Bucket 24 size=112
    Bucket 25 size=116
    Bucket 26 size=120
    Bucket 27 size=124
    Bucket 28 size=128
    Bucket 29 size=132
    Bucket 30 size=136
    Bucket 31 size=140
    Bucket 32 size=144
    Bucket 33 size=148
    Bucket 34 size=152
    Bucket 35 size=156
    Bucket 36 size=160
    Bucket 37 size=164
    Bucket 38 size=168
    Bucket 39 size=172
    Bucket 40 size=176
    Bucket 41 size=180
    Bucket 42 size=184
    Bucket 43 size=188
    Bucket 44 size=192
    Bucket 45 size=196
    Bucket 46 size=200
    Bucket 47 size=204
    Bucket 48 size=208
    Bucket 49 size=212
    Bucket 50 size=216
    Bucket 51 size=220
    Bucket 52 size=224
    Bucket 53 size=228
    Bucket 54 size=232
    Bucket 55 size=236
    Bucket 56 size=240
    Bucket 57 size=244
    Bucket 58 size=248
    Bucket 59 size=252
    Bucket 60 size=256
    Bucket 61 size=260
    Bucket 62 size=264
    Bucket 63 size=268
    Bucket 64 size=272
    Bucket 65 size=276
    Bucket 66 size=280
    Bucket 67 size=284
    Bucket 68 size=288
    Bucket 69 size=292
    Bucket 70 size=296
    Bucket 71 size=300
    Bucket 72 size=304
    Bucket 73 size=308
    Bucket 74 size=312
    Bucket 75 size=316
    Bucket 76 size=320
    Bucket 77 size=324
    Bucket 78 size=328
    Bucket 79 size=332
    Bucket 80 size=336
    Bucket 81 size=340
    Bucket 82 size=344
    Bucket 83 size=348
    Bucket 84 size=352
    Bucket 85 size=356
    Bucket 86 size=360
    Bucket 87 size=364
    Bucket 88 size=368
    Bucket 89 size=372
    Bucket 90 size=376
    Bucket 91 size=380
    Bucket 92 size=384
    Bucket 93 size=388
    Bucket 94 size=392
    Bucket 95 size=396
    Bucket 96 size=400
    Bucket 97 size=404
    Bucket 98 size=408
    Bucket 99 size=412
    Bucket 100 size=416
    Bucket 101 size=420
    Bucket 102 size=424
    Bucket 103 size=428
    Bucket 104 size=432
    Bucket 105 size=436
    Bucket 106 size=440
    Bucket 107 size=444
    Bucket 108 size=448
    Bucket 109 size=452
    Bucket 110 size=456
    Bucket 111 size=460
    Bucket 112 size=464
    Bucket 113 size=468
    Bucket 114 size=472
    Bucket 115 size=476
    Bucket 116 size=480
    Bucket 117 size=484
    Bucket 118 size=488
    Bucket 119 size=492
    Bucket 120 size=496
    Bucket 121 size=500
    Bucket 122 size=504
    Bucket 123 size=508
    Bucket 124 size=512
    Bucket 125 size=516
    Bucket 126 size=520
    Bucket 127 size=524
    Bucket 128 size=528
    Bucket 129 size=532
    Bucket 130 size=536
    Bucket 131 size=540
    Bucket 132 size=544
    Bucket 133 size=548
    Bucket 134 size=552
    Bucket 135 size=556
    Bucket 136 size=560
    Bucket 137 size=564
    Bucket 138 size=568
    Bucket 139 size=572
    Bucket 140 size=576
    Bucket 141 size=580
    Bucket 142 size=584
    Bucket 143 size=588
    Bucket 144 size=592
    Bucket 145 size=596
    Bucket 146 size=600
    Bucket 147 size=604
    Bucket 148 size=608
    Bucket 149 size=612
    Bucket 150 size=616
    Bucket 151 size=620
    Bucket 152 size=624
    Bucket 153 size=628
    Bucket 154 size=632
    Bucket 155 size=636
    Bucket 156 size=640
    Bucket 157 size=644
    Bucket 158 size=648
    Bucket 159 size=652
    Bucket 160 size=656
    Bucket 161 size=660
    Bucket 162 size=664
    Bucket 163 size=668
    Bucket 164 size=672
    Bucket 165 size=676
    Bucket 166 size=680
    Bucket 167 size=684
    Bucket 168 size=688
    Bucket 169 size=692
    Bucket 170 size=696
    Bucket 171 size=700
    Bucket 172 size=704
    Bucket 173 size=708
    Bucket 174 size=712
    Bucket 175 size=716
    Bucket 176 size=720
    Bucket 177 size=724
    Bucket 178 size=728
    Bucket 179 size=732
    Bucket 180 size=736
    Bucket 181 size=740
    Bucket 182 size=744
    Bucket 183 size=748
    Bucket 184 size=752
    Bucket 185 size=756
    Bucket 186 size=760
    Bucket 187 size=764
    Bucket 188 size=768
    Bucket 189 size=772
    Bucket 190 size=776
    Bucket 191 size=780
    Bucket 192 size=784
    Bucket 193 size=788
    Bucket 194 size=792
    Bucket 195 size=796
    Bucket 196 size=800
    Bucket 197 size=804
    Bucket 198 size=808
    Bucket 199 size=812
    Bucket 200 size=876
    Bucket 201 size=940
    Bucket 202 size=1004
    Bucket 203 size=1068
    Bucket 204 size=1132
    Bucket 205 size=1196
    Bucket 206 size=1260
    Bucket 207 size=1324
    Bucket 208 size=1388
    Bucket 209 size=1452
    Bucket 210 size=1516
    Bucket 211 size=1580
    Bucket 212 size=1644
    Bucket 213 size=1708
    Bucket 214 size=1772
    Bucket 215 size=1836
    Bucket 216 size=1900
    Bucket 217 size=1964
    Bucket 218 size=2028
    Bucket 219 size=2092
    Bucket 220 size=2156
    Bucket 221 size=2220
    Bucket 222 size=2284
    Bucket 223 size=2348
    Bucket 224 size=2412
    Bucket 225 size=2476
    Bucket 226 size=2540
    Bucket 227 size=2604
    Bucket 228 size=2668
    Bucket 229 size=2732
    Bucket 230 size=2796
    Bucket 231 size=2860
    Bucket 232 size=2924
    Bucket 233 size=2988
    Bucket 234 size=3052
    Bucket 235 size=3116
    Bucket 236 size=3180
    Bucket 237 size=3244
    Bucket 238 size=3308
    Bucket 239 size=3372
    Bucket 240 size=3436
    Bucket 241 size=3500
    Bucket 242 size=3564
    Bucket 243 size=3628
    Bucket 244 size=3692
    Bucket 245 size=3756
    Bucket 246 size=3820
    Bucket 247 size=3884
    Bucket 248 size=3948
    Bucket 249 size=4012
    Bucket 250 size=4108
    Bucket 251 size=8204
    Bucket 252 size=16396
    Bucket 253 size=32780
    Bucket 254 size=65548

     

    我们看到,在Oracle9i中,Free Lists被划分为0~254,共255个Bucket
    每个Bucket容纳的size范围
    Bucket 0~199 容纳size以 4 递增
    Bucket 200~249 容纳size以 64 递增

    从Bucket 249开始,Oracle各Bucket步长进一步增加:

    Bucket 249: 4012 ~4107 = 96
    Bucket 250: 4108 ~8203 = 4096
    Bucket 251: 8204 ~16395 = 8192
    Bucket 252: 16396~32779 = 16384
    Bucket 253: 32780~65547 = 32768
    Bucket 254: >=65548

    在Oracle9i中,对于小的chunk,Oracle增加了更多的Bucket来管理
    0~199共200个Bucket,size以4为步长递增;200~249共50个Bucket,size以64递增.
    这样每个Bucket中容纳的chunk数量大大减少,查找的效率得以提高.

    这就是Oracle9i中shared pool管理的增强,通过这个算法的改进
    Oracle8i中,过大shared pool带来的栓锁争用等性能问题在某种程度上得以解决.

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    无觅

    By eygle on 2004-10-31 09:29 | Comments (6) | Internal | 85 |

    6 Comments

    请问 eygle, 这篇文章中所涉及到的 gettrcname脚本要在哪里下载啊?

    看看:
    http://www.eygle.com/archives/2007/09/11g_tracefile_name.html

    收到,,,,

    SQL> alter session set events 'immediate trace name heapdump level 2';

    Session altered.

    SQL> select * from v$version;

    BANNER
    ----------------------------------------------------------------
    Oracle8i Enterprise Edition Release 8.1.7.0.1 - Production
    PL/SQL Release 8.1.7.0.0 - Production
    CORE 8.1.7.0.0 Production
    TNS for Linux: Version 8.1.7.0.0 - Development
    NLSRTL Version 3.4.1.0.0 - Production

    [oracle@xfyan udump]$ cat ora_6169.trc | grep Bucket
    Bucket 0 size=16
    Bucket 1 size=20
    Bucket 2 size=24
    Bucket 3 size=28
    Bucket 4 size=32
    Bucket 5 size=36
    Bucket 6 size=40
    Bucket 7 size=44
    Bucket 8 size=48
    Bucket 9 size=52
    Bucket 10 size=56
    Bucket 11 size=60
    Bucket 12 size=64
    Bucket 13 size=68
    Bucket 14 size=72
    Bucket 15 size=76
    Bucket 16 size=80
    Bucket 17 size=84
    Bucket 18 size=88
    Bucket 19 size=92
    Bucket 20 size=96
    Bucket 21 size=100
    Bucket 22 size=104
    Bucket 23 size=108
    Bucket 24 size=112
    Bucket 25 size=116
    Bucket 26 size=120
    Bucket 27 size=124
    Bucket 28 size=128
    Bucket 29 size=132
    Bucket 30 size=136
    Bucket 31 size=140
    Bucket 32 size=144
    Bucket 33 size=148
    Bucket 34 size=152
    Bucket 35 size=156
    Bucket 36 size=160
    Bucket 37 size=164
    Bucket 38 size=168
    Bucket 39 size=172
    Bucket 40 size=176
    Bucket 41 size=180
    Bucket 42 size=184
    Bucket 43 size=188
    Bucket 44 size=192
    Bucket 45 size=196
    Bucket 46 size=200
    Bucket 47 size=204
    Bucket 48 size=208
    Bucket 49 size=212
    Bucket 50 size=216
    Bucket 51 size=220
    Bucket 52 size=224
    Bucket 53 size=228
    Bucket 54 size=232
    Bucket 55 size=236
    Bucket 56 size=240
    Bucket 57 size=244
    Bucket 58 size=248
    Bucket 59 size=252
    Bucket 60 size=256
    Bucket 61 size=260
    Bucket 62 size=264
    Bucket 63 size=268
    Bucket 64 size=272
    Bucket 65 size=276
    Bucket 66 size=280
    Bucket 67 size=284
    Bucket 68 size=288
    Bucket 69 size=292
    Bucket 70 size=296
    Bucket 71 size=300
    Bucket 72 size=304
    Bucket 73 size=308
    Bucket 74 size=312
    Bucket 75 size=316
    Bucket 76 size=320
    Bucket 77 size=324
    Bucket 78 size=328
    Bucket 79 size=332
    Bucket 80 size=336
    Bucket 81 size=340
    Bucket 82 size=344
    Bucket 83 size=348
    Bucket 84 size=352
    Bucket 85 size=356
    Bucket 86 size=360
    Bucket 87 size=364
    Bucket 88 size=368
    Bucket 89 size=372
    Bucket 90 size=376
    Bucket 91 size=380
    Bucket 92 size=384
    Bucket 93 size=388
    Bucket 94 size=392
    Bucket 95 size=396
    Bucket 96 size=400
    Bucket 97 size=404
    Bucket 98 size=408
    Bucket 99 size=412
    Bucket 100 size=416
    Bucket 101 size=420
    Bucket 102 size=424
    Bucket 103 size=428
    Bucket 104 size=432
    Bucket 105 size=436
    Bucket 106 size=440
    Bucket 107 size=444
    Bucket 108 size=448
    Bucket 109 size=452
    Bucket 110 size=456
    Bucket 111 size=460
    Bucket 112 size=464
    Bucket 113 size=468
    Bucket 114 size=472
    Bucket 115 size=476
    Bucket 116 size=480
    Bucket 117 size=484
    Bucket 118 size=488
    Bucket 119 size=492
    Bucket 120 size=496
    Bucket 121 size=500
    Bucket 122 size=504
    Bucket 123 size=508
    Bucket 124 size=512
    Bucket 125 size=516
    Bucket 126 size=520
    Bucket 127 size=524
    Bucket 128 size=528
    Bucket 129 size=532
    Bucket 130 size=536
    Bucket 131 size=540
    Bucket 132 size=544
    Bucket 133 size=548
    Bucket 134 size=552
    Bucket 135 size=556
    Bucket 136 size=560
    Bucket 137 size=564
    Bucket 138 size=568
    Bucket 139 size=572
    Bucket 140 size=576
    Bucket 141 size=580
    Bucket 142 size=584
    Bucket 143 size=588
    Bucket 144 size=592
    Bucket 145 size=596
    Bucket 146 size=600
    Bucket 147 size=604
    Bucket 148 size=608
    Bucket 149 size=612
    Bucket 150 size=616
    Bucket 151 size=620
    Bucket 152 size=624
    Bucket 153 size=628
    Bucket 154 size=632
    Bucket 155 size=636
    Bucket 156 size=640
    Bucket 157 size=644
    Bucket 158 size=648
    Bucket 159 size=652
    Bucket 160 size=656
    Bucket 161 size=660
    Bucket 162 size=664
    Bucket 163 size=668
    Bucket 164 size=672
    Bucket 165 size=676
    Bucket 166 size=680
    Bucket 167 size=684
    Bucket 168 size=688
    Bucket 169 size=692
    Bucket 170 size=696
    Bucket 171 size=700
    Bucket 172 size=704
    Bucket 173 size=708
    Bucket 174 size=712
    Bucket 175 size=716
    Bucket 176 size=720
    Bucket 177 size=724
    Bucket 178 size=728
    Bucket 179 size=732
    Bucket 180 size=736
    Bucket 181 size=740
    Bucket 182 size=744
    Bucket 183 size=748
    Bucket 184 size=752
    Bucket 185 size=756
    Bucket 186 size=760
    Bucket 187 size=764
    Bucket 188 size=768
    Bucket 189 size=772
    Bucket 190 size=776
    Bucket 191 size=780
    Bucket 192 size=784
    Bucket 193 size=788
    Bucket 194 size=792
    Bucket 195 size=796
    Bucket 196 size=800
    Bucket 197 size=804
    Bucket 198 size=808
    Bucket 199 size=812
    Bucket 200 size=876
    Bucket 201 size=940
    Bucket 202 size=1004
    Bucket 203 size=1068
    Bucket 204 size=1132
    Bucket 205 size=1196
    Bucket 206 size=1260
    Bucket 207 size=1324
    Bucket 208 size=1388
    Bucket 209 size=1452
    Bucket 210 size=1516
    Bucket 211 size=1580
    Bucket 212 size=1644
    Bucket 213 size=1708
    Bucket 214 size=1772
    Bucket 215 size=1836
    Bucket 216 size=1900
    Bucket 217 size=1964
    Bucket 218 size=2028
    Bucket 219 size=2092
    Bucket 220 size=2156
    Bucket 221 size=2220
    Bucket 222 size=2284
    Bucket 223 size=2348
    Bucket 224 size=2412
    Bucket 225 size=2476
    Bucket 226 size=2540
    Bucket 227 size=2604
    Bucket 228 size=2668
    Bucket 229 size=2732
    Bucket 230 size=2796
    Bucket 231 size=2860
    Bucket 232 size=2924
    Bucket 233 size=2988
    Bucket 234 size=3052
    Bucket 235 size=3116
    Bucket 236 size=3180
    Bucket 237 size=3244
    Bucket 238 size=3308
    Bucket 239 size=3372
    Bucket 240 size=3436
    Bucket 241 size=3500
    Bucket 242 size=3564
    Bucket 243 size=3628
    Bucket 244 size=3692
    Bucket 245 size=3756
    Bucket 246 size=3820
    Bucket 247 size=3884
    Bucket 248 size=3948
    Bucket 249 size=4012
    Bucket 250 size=4108
    Bucket 251 size=8204
    Bucket 252 size=16396
    Bucket 253 size=32780
    Bucket 254 size=65548

    操作系统为redhat 4.7

    我的测试环境中生成的trace文件ora_6169.trc,这里不包含$ORACLE_SID,oracle81701中bucket的数量已经达到254个了,这几个东东应该是oracle版本和操作系统版本不同造成的

    SQL> alter session set events 'immediate trace name heapdump level 2';

    Session altered.

    SQL> select * from v$version;

    BANNER
    ----------------------------------------------------------------
    Oracle8i Enterprise Edition Release 8.1.7.0.1 - Production
    PL/SQL Release 8.1.7.0.0 - Production
    CORE 8.1.7.0.0 Production
    TNS for Linux: Version 8.1.7.0.0 - Development
    NLSRTL Version 3.4.1.0.0 - Production

    [oracle@xfyan udump]$ cat ora_6169.trc | grep Bucket
    Bucket 0 size=16
    Bucket 1 size=20
    Bucket 2 size=24
    Bucket 3 size=28
    Bucket 4 size=32
    Bucket 5 size=36
    Bucket 6 size=40
    Bucket 7 size=44
    Bucket 8 size=48
    Bucket 9 size=52
    Bucket 10 size=56
    Bucket 11 size=60
    Bucket 12 size=64
    Bucket 13 size=68
    Bucket 14 size=72
    Bucket 15 size=76
    Bucket 16 size=80
    Bucket 17 size=84
    Bucket 18 size=88
    Bucket 19 size=92
    Bucket 20 size=96
    Bucket 21 size=100
    Bucket 22 size=104
    Bucket 23 size=108
    Bucket 24 size=112
    Bucket 25 size=116
    Bucket 26 size=120
    Bucket 27 size=124
    Bucket 28 size=128
    Bucket 29 size=132
    Bucket 30 size=136
    Bucket 31 size=140
    Bucket 32 size=144
    Bucket 33 size=148
    Bucket 34 size=152
    Bucket 35 size=156
    Bucket 36 size=160
    Bucket 37 size=164
    Bucket 38 size=168
    Bucket 39 size=172
    Bucket 40 size=176
    Bucket 41 size=180
    Bucket 42 size=184
    Bucket 43 size=188
    Bucket 44 size=192
    Bucket 45 size=196
    Bucket 46 size=200
    Bucket 47 size=204
    Bucket 48 size=208
    Bucket 49 size=212
    Bucket 50 size=216
    Bucket 51 size=220
    Bucket 52 size=224
    Bucket 53 size=228
    Bucket 54 size=232
    Bucket 55 size=236
    Bucket 56 size=240
    Bucket 57 size=244
    Bucket 58 size=248
    Bucket 59 size=252
    Bucket 60 size=256
    Bucket 61 size=260
    Bucket 62 size=264
    Bucket 63 size=268
    Bucket 64 size=272
    Bucket 65 size=276
    Bucket 66 size=280
    Bucket 67 size=284
    Bucket 68 size=288
    Bucket 69 size=292
    Bucket 70 size=296
    Bucket 71 size=300
    Bucket 72 size=304
    Bucket 73 size=308
    Bucket 74 size=312
    Bucket 75 size=316
    Bucket 76 size=320
    Bucket 77 size=324
    Bucket 78 size=328
    Bucket 79 size=332
    Bucket 80 size=336
    Bucket 81 size=340
    Bucket 82 size=344
    Bucket 83 size=348
    Bucket 84 size=352
    Bucket 85 size=356
    Bucket 86 size=360
    Bucket 87 size=364
    Bucket 88 size=368
    Bucket 89 size=372
    Bucket 90 size=376
    Bucket 91 size=380
    Bucket 92 size=384
    Bucket 93 size=388
    Bucket 94 size=392
    Bucket 95 size=396
    Bucket 96 size=400
    Bucket 97 size=404
    Bucket 98 size=408
    Bucket 99 size=412
    Bucket 100 size=416
    Bucket 101 size=420
    Bucket 102 size=424
    Bucket 103 size=428
    Bucket 104 size=432
    Bucket 105 size=436
    Bucket 106 size=440
    Bucket 107 size=444
    Bucket 108 size=448
    Bucket 109 size=452
    Bucket 110 size=456
    Bucket 111 size=460
    Bucket 112 size=464
    Bucket 113 size=468
    Bucket 114 size=472
    Bucket 115 size=476
    Bucket 116 size=480
    Bucket 117 size=484
    Bucket 118 size=488
    Bucket 119 size=492
    Bucket 120 size=496
    Bucket 121 size=500
    Bucket 122 size=504
    Bucket 123 size=508
    Bucket 124 size=512
    Bucket 125 size=516
    Bucket 126 size=520
    Bucket 127 size=524
    Bucket 128 size=528
    Bucket 129 size=532
    Bucket 130 size=536
    Bucket 131 size=540
    Bucket 132 size=544
    Bucket 133 size=548
    Bucket 134 size=552
    Bucket 135 size=556
    Bucket 136 size=560
    Bucket 137 size=564
    Bucket 138 size=568
    Bucket 139 size=572
    Bucket 140 size=576
    Bucket 141 size=580
    Bucket 142 size=584
    Bucket 143 size=588
    Bucket 144 size=592
    Bucket 145 size=596
    Bucket 146 size=600
    Bucket 147 size=604
    Bucket 148 size=608
    Bucket 149 size=612
    Bucket 150 size=616
    Bucket 151 size=620
    Bucket 152 size=624
    Bucket 153 size=628
    Bucket 154 size=632
    Bucket 155 size=636
    Bucket 156 size=640
    Bucket 157 size=644
    Bucket 158 size=648
    Bucket 159 size=652
    Bucket 160 size=656
    Bucket 161 size=660
    Bucket 162 size=664
    Bucket 163 size=668
    Bucket 164 size=672
    Bucket 165 size=676
    Bucket 166 size=680
    Bucket 167 size=684
    Bucket 168 size=688
    Bucket 169 size=692
    Bucket 170 size=696
    Bucket 171 size=700
    Bucket 172 size=704
    Bucket 173 size=708
    Bucket 174 size=712
    Bucket 175 size=716
    Bucket 176 size=720
    Bucket 177 size=724
    Bucket 178 size=728
    Bucket 179 size=732
    Bucket 180 size=736
    Bucket 181 size=740
    Bucket 182 size=744
    Bucket 183 size=748
    Bucket 184 size=752
    Bucket 185 size=756
    Bucket 186 size=760
    Bucket 187 size=764
    Bucket 188 size=768
    Bucket 189 size=772
    Bucket 190 size=776
    Bucket 191 size=780
    Bucket 192 size=784
    Bucket 193 size=788
    Bucket 194 size=792
    Bucket 195 size=796
    Bucket 196 size=800
    Bucket 197 size=804
    Bucket 198 size=808
    Bucket 199 size=812
    Bucket 200 size=876
    Bucket 201 size=940
    Bucket 202 size=1004
    Bucket 203 size=1068
    Bucket 204 size=1132
    Bucket 205 size=1196
    Bucket 206 size=1260
    Bucket 207 size=1324
    Bucket 208 size=1388
    Bucket 209 size=1452
    Bucket 210 size=1516
    Bucket 211 size=1580
    Bucket 212 size=1644
    Bucket 213 size=1708
    Bucket 214 size=1772
    Bucket 215 size=1836
    Bucket 216 size=1900
    Bucket 217 size=1964
    Bucket 218 size=2028
    Bucket 219 size=2092
    Bucket 220 size=2156
    Bucket 221 size=2220
    Bucket 222 size=2284
    Bucket 223 size=2348
    Bucket 224 size=2412
    Bucket 225 size=2476
    Bucket 226 size=2540
    Bucket 227 size=2604
    Bucket 228 size=2668
    Bucket 229 size=2732
    Bucket 230 size=2796
    Bucket 231 size=2860
    Bucket 232 size=2924
    Bucket 233 size=2988
    Bucket 234 size=3052
    Bucket 235 size=3116
    Bucket 236 size=3180
    Bucket 237 size=3244
    Bucket 238 size=3308
    Bucket 239 size=3372
    Bucket 240 size=3436
    Bucket 241 size=3500
    Bucket 242 size=3564
    Bucket 243 size=3628
    Bucket 244 size=3692
    Bucket 245 size=3756
    Bucket 246 size=3820
    Bucket 247 size=3884
    Bucket 248 size=3948
    Bucket 249 size=4012
    Bucket 250 size=4108
    Bucket 251 size=8204
    Bucket 252 size=16396
    Bucket 253 size=32780
    Bucket 254 size=65548

    操作系统为redhat 4.7
    生成的trace文件不包含$ORACLE_SID
    shared_pool有254个Bucket

    这个东东可能是由于操作系统和oracle版本造成的

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  • 原文地址:https://www.cnblogs.com/youngerger/p/8538538.html
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