DB2 runstats和reorg操作

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标题:DB2 runstats和reorg操作

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db2收集统计信息(runstats)

[db2inst1@xifenfei ~]$ db2 connect to xff

   Database Connection Information

 Database server        = DB2/LINUX 9.5.9
 SQL authorization ID   = DB2INST1
 Local database alias   = XFF

[db2inst1@xifenfei ~]$ db2 list tables

Table/View                      Schema          Type  Creation time             
------------------------------- --------------- ----- --------------------------
T_01XFF                         DB2INST1        T     2012-04-11-18.23.05.723478
T_02XFF                         DB2INST1        T     2012-04-11-18.30.26.639326
T_03XFF                         DB2INST1        T     2012-04-11-21.33.12.479480

  3 record(s) selected.

[db2inst1@xifenfei ~]$ db2 "select STATS_TIME from syscat.tables where tabname in('T_01XFF','T_02XFF','T_03XFF')"

STATS_TIME                
--------------------------
2012-04-12-04.35.07.539790
2012-04-11-19.55.12.023748
2012-04-11-22.20.07.016905

  3 record(s) selected.

--收集表和索引统计信息,包括数据分布
[db2inst1@xifenfei ~]$ db2 "runstats on table db2inst1.t_01xff on all columns
with distribution and detailed indexes all"
DB20000I  The RUNSTATS command completed successfully.
[db2inst1@xifenfei ~]$ db2 "select STATS_TIME from syscat.tables where tabname in('T_01XFF')"

STATS_TIME                
--------------------------
2012-04-28-23.43.23.904759

  1 record(s) selected.

--收集索引统计信息,如果表没有被收集,也会同时对表收集统计信息,对不会收集数据分布信息
[db2inst1@xifenfei ~]$ db2 "runstats on table db2inst1.t_02xff for  indexes all"
DB20000I  The RUNSTATS command completed successfully.


[db2inst1@xifenfei ~]$ db2 "select STATS_TIME from syscat.tables where tabname in('T_01XFF','T_02XFF')"

STATS_TIME                
--------------------------
2012-04-28-23.43.23.904759
2012-04-28-23.44.39.762858

  2 record(s) selected.

db2 reorg操作

--删除部分表数据
[db2inst1@xifenfei ~]$ db2 "delete from t_01xff"
DB20000I  The SQL command completed successfully.
[db2inst1@xifenfei ~]$ db2 "delete from t_03xff"
DB20000I  The SQL command completed successfully.

--reorgchk检查是否需要进行reorg
[db2inst1@xifenfei ~]$ db2 reorgchk on schema db2inst1

Doing RUNSTATS ....


Table statistics:

F1: 100 * OVERFLOW / CARD < 5
F2: 100 * (Effective Space Utilization of Data Pages) > 70
F3: 100 * (Required Pages / Total Pages) > 80

SCHEMA.NAME                     CARD     OV     NP     FP ACTBLK    TSIZE  F1  F2  F3 REORG
----------------------------------------------------------------------------------------
Table: DB2INST1.T_01XFF
                                   0      0      0     42      -        0   0   0   0 -** 
Table: DB2INST1.T_02XFF
                                 371      0     42     42      -   152110   0 100 100 --- 
Table: DB2INST1.T_03XFF
                                   0      0      0     83      -        0   0   0   0 -** 
----------------------------------------------------------------------------------------

Index statistics:

F4: CLUSTERRATIO or normalized CLUSTERFACTOR > 80
F5: 100 * (Space used on leaf pages / Space available on non-empty leaf pages) > MIN(50, (100 - PCTFREE))
F6: (100 - PCTFREE) * (Amount of space available in an index with one less level / Amount of space required for all keys) < 100
F7: 100 * (Number of pseudo-deleted RIDs / Total number of RIDs) < 20
F8: 100 * (Number of pseudo-empty leaf pages / Total number of leaf pages) < 20

SCHEMA.NAME                 INDCARD  LEAF ELEAF LVLS  NDEL    KEYS LEAF_RECSIZE NLEAF_RECSIZE LEAF_PAGE_OVERHEAD NLEAF_PAGE_OVERHEAD  F4  F5  F6  F7  F8 REORG  
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Table: DB2INST1.T_01XFF
Index: DB2INST1.I_T_01XFF
                                  0     3     3    2     0       0            2             2                822                 822 100   0   -   0 100 ----* 
--------------------------------------------------------------------------------------------------------------------------------------------------------------

CLUSTERRATIO or normalized CLUSTERFACTOR (F4) will indicate REORG is necessary 
for indexes that are not in the same sequence as the base table. When multiple 
indexes are defined on a table, one or more indexes may be flagged as needing 
REORG.  Specify the most important index for REORG sequencing.

Tables defined using the ORGANIZE BY clause and the corresponding dimension 
indexes have a '*' suffix to their names. The cardinality of a dimension index 
is equal to the Active blocks statistic of the table.

--离线reorg index
[db2inst1@xifenfei ~]$ db2 reorg table db2inst1.t_01xff index DB2INST1.I_T_01XFF allow read access
DB20000I  The REORG command completed successfully.

--在线reorg table
[db2inst1@xifenfei ~]$ db2 reorg table db2inst1.t_01xff inplace allow write access
DB20000I  The REORG command completed successfully.
DB21024I  This command is asynchronous and may not be effective immediately.

[db2inst1@xifenfei ~]$ db2 reorg table db2inst1.t_03xff inplace allow write access
DB20000I  The REORG command completed successfully.
DB21024I  This command is asynchronous and may not be effective immediately.

--证明异步操作完成
[db2inst1@xifenfei ~]$ ps -ef|grep db2reo
db2inst1  1496  1311  0 00:24 pts/1    00:00:00 grep db2reo

--检查reorg操作结果
[db2inst1@xifenfei ~]$ db2 reorgchk on schema db2inst1

Doing RUNSTATS ....


Table statistics:

F1: 100 * OVERFLOW / CARD < 5
F2: 100 * (Effective Space Utilization of Data Pages) > 70
F3: 100 * (Required Pages / Total Pages) > 80

SCHEMA.NAME                     CARD     OV     NP     FP ACTBLK    TSIZE  F1  F2  F3 REORG
----------------------------------------------------------------------------------------
Table: DB2INST1.T_01XFF
                                   0      0      0      1      -        0   0   -   0 --- 
Table: DB2INST1.T_02XFF
                                 371      0     42     42      -   152110   0 100 100 --- 
Table: DB2INST1.T_03XFF
                                   0      0      0      1      -        0   0   -   0 --- 
----------------------------------------------------------------------------------------

Index statistics:

F4: CLUSTERRATIO or normalized CLUSTERFACTOR > 80
F5: 100 * (Space used on leaf pages / Space available on non-empty leaf pages) > MIN(50, (100 - PCTFREE))
F6: (100 - PCTFREE) * (Amount of space available in an index with one less level / Amount of space required for all keys) < 100
F7: 100 * (Number of pseudo-deleted RIDs / Total number of RIDs) < 20
F8: 100 * (Number of pseudo-empty leaf pages / Total number of leaf pages) < 20

SCHEMA.NAME                 INDCARD  LEAF ELEAF LVLS  NDEL    KEYS LEAF_RECSIZE NLEAF_RECSIZE LEAF_PAGE_OVERHEAD NLEAF_PAGE_OVERHEAD  F4  F5  F6  F7  F8 REORG  
--------------------------------------------------------------------------------------------------------------------------------------------------------------
Table: DB2INST1.T_01XFF
Index: DB2INST1.I_T_01XFF
                                  0     1     0    1     0       0            2             2                822                 822 100   -   -   0   0 ----- 
--------------------------------------------------------------------------------------------------------------------------------------------------------------

CLUSTERRATIO or normalized CLUSTERFACTOR (F4) will indicate REORG is necessary 
for indexes that are not in the same sequence as the base table. When multiple 
indexes are defined on a table, one or more indexes may be flagged as needing 
REORG.  Specify the most important index for REORG sequencing.

Tables defined using the ORGANIZE BY clause and the corresponding dimension 
indexes have a '*' suffix to their names. The cardinality of a dimension index 
is equal to the Active blocks statistic of the table.
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