DB2 10.5 BLU列式存储技术初试

文章由LinuxBoy分享于2019-03-30 01:03:28热评（421）

DB2 10.5 BLU列式存储技术初试

2013年IBM DB2 30周岁啦，在此DB2 10.5发布了，其中一个比较抢眼的特性就是BLU加速器，也就是讲列式存储技术开始引入传统数据库中，但目前BLU特性只是支持一些特定的的版本主要是AIX和linux 64位平台的DB2 AESE版本的数据库，所以外界其实能接触的机会并不多，先给大家看看BLU的配置吧。

我使用的DB2版本及license信息：

db2level -a
DB21085I This instance or install (instance name, where applicable: "db2deer")
uses "64" bits and DB2 code release "SQL10053" with level identifier
"0604010E".
Informational tokens are "DB2 v10.5.0.3", "s140203", "IP23544", and Fix Pack
"3".
Product is installed at "/opt/IBM/db2/V10.5".

db2licm -l
Product name: "DB2 Advanced Enterprise Server Edition"
License type: "Terabyte"
Expiry date: "Permanent"
Product identifier: "db2aese"
Version information: "10.5"
Enforcement policy: "Soft Stop"

最简单的配置列式存储的方式是，使用用户环境变量参数DB2_WORKLOAD，DB2 10.5多了个取值

db2set DB2_WORKLOAD=ANALYTICS

设置好后重启实例即可，此时创建DB即可支持列式存储

当然还有就是从低版本升级过来或者之前未启用列式存储的，DB也提供了简单的自动配置方法，修改以上参数后重启实例，然后使用自动配置即可：

db2 autoconfigure apply db only

Current and Recommended Values for Database Manager Configuration

Description Parameter Current Value Recommended Value
-------------------------------------------------------------------------------------------------
Application support layer heap size (4KB) (ASLHEAPSZ) = 15
No. of int. communication buffers(4KB)(FCM_NUM_BUFFERS) = AUTOMATIC
Enable intra-partition parallelism (INTRA_PARALLEL) = NO
Maximum query degree of parallelism (MAX_QUERYDEGREE) = 7
Agent pool size (NUM_POOLAGENTS) = AUTOMATIC(100)
Initial number of agents in pool (NUM_INITAGENTS) = 0
Max requester I/O block size (bytes) (RQRIOBLK) = 65535
Sort heap threshold (4KB) (SHEAPTHRES) = 0

Former and Applied Values for Database Configuration

Description Parameter Former Value Applied Value
-------------------------------------------------------------------------------------------------
Default application heap (4KB) (APPLHEAPSZ) = 256 256
Catalog cache size (4KB) (CATALOGCACHE_SZ) = 402 482
Changed pages threshold (CHNGPGS_THRESH) = 80 80
Database heap (4KB) (DBHEAP) = 6283 6306
Degree of parallelism (DFT_DEGREE) = ANY ANY
Default tablespace extentsize (pages) (DFT_EXTENT_SZ) = 32 32
Default prefetch size (pages) (DFT_PREFETCH_SZ) = AUTOMATIC AUTOMATIC
Default query optimization class (DFT_QUERYOPT) = 5 5
Max storage for lock list (4KB) (LOCKLIST) = AUTOMATIC AUTOMATIC
Log file size (4KB) (LOGFILSIZ) = 1024 1024
Number of primary log files (LOGPRIMARY) = 8 19
Number of secondary log files (LOGSECOND) = 11 13
Max number of active applications (MAXAPPLS) = AUTOMATIC AUTOMATIC
Percent. of lock lists per application (MAXLOCKS) = AUTOMATIC AUTOMATIC
Number of asynchronous page cleaners (NUM_IOCLEANERS) = 14 1
Number of I/O servers (NUM_IOSERVERS) = 32 6
Package cache size (4KB) (PCKCACHESZ) = AUTOMATIC AUTOMATIC
Sort list heap (4KB) (SORTHEAP) = AUTOMATIC 47808
SQL statement heap (4KB) (STMTHEAP) = 8192 16384
Statistics heap size (4KB) (STAT_HEAP_SZ) = 4384 4384
Utilities heap size (4KB) (UTIL_HEAP_SZ) = AUTOMATIC AUTOMATIC
Self tuning memory (SELF_TUNING_MEM) = ON ON
Automatic runstats (AUTO_RUNSTATS) = ON ON
Sort heap thres for shared sorts (4KB) (SHEAPTHRES_SHR) = AUTOMATIC 956160
Log buffer size (4KB) (LOGBUFSZ) = 2152 2152
Default table organization (DFT_TABLE_ORG) = ROW COLUMN
Database memory threshold (DB_MEM_THRESH) = 100 100

Former and Applied Values for Bufferpool(s)

Description Parameter Former Value Applied Value
-------------------------------------------------------------------------------------------------
IBMDEFAULTBP Bufferpool size = -2 119520

Former and Applied Values for System WLM Objects

Description Former Value Applied Value
-------------------------------------------------------------------------------------------------
Work Action SYSMAPMANAGEDQUERIES Enabled = Y Y
Work Action Set SYSDEFAULTUSERWAS Enabled = Y Y
Work Class SYSMANAGEDQUERIES Timeroncost = 1.50000E+05 1.50000E+05
Threshold SYSDEFAULTCONCURRENT Enabled = N Y
Threshold SYSDEFAULTCONCURRENT Maxvalue = 13 13

DB210203I AUTOCONFIGURE completed successfully. Database manager or database
configuration values may have been changed if you chose to apply changes. The
instance must be restarted before any such applied changes come into effect.
You may also want to rebind your packages after the new configuration
parameters take effect so that the new values will be used.

可以看到DFT_TABLE_ORG的值由row修改为column了，也就是以后创建的表默认就是列式存储表了，据测试来看列式存储确实在空间使用和SQL查询效率上提高了很多，不过改特性只能支持单表的，对于分表/DPF/MDC/PureScale环境下的表还是不能支持的，好，现在就说初步了解下，以后会有更多的实际应用案例吧。

DB2数据库性能调整和优化(第1、2版) PDF

DB2数据库性能优化介绍

本文永久更新链接地址：

推荐文章：

DB2 10.5 BLU列式存储技术初试