TimesTen 应用层数据库缓存学习：19. 理解AWT缓存组的三种模式

概述

本文很好的讲述了AWT三种缓存组的概念和区别，并给出了3种缓存组从建立到摧毁的完整过程。

AWT缓存组有3中类型：

1. AWT 缺省 (Manually load)

2. AWT Dynamic

3. AWT Dynamic Globle (Cache Grid)

各种AWT类型的区别

AWT 缺省 (Manually load)

TimesTen中inserted/updated/deleted的数据传递到Oracle

Oracle中新增的数据通过”LOAD CACHE GROUP”同步到TimesTen

如果一个表缓存到两个AWT 缺省Cache Group，缓存组之间并不相互知情，因此一个cache instance可以同时存在于两个缓存组中

语法：

create asynchronous writethrough cache group t1_awt_reg

from t1 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

AWT Dynamic

TimesTen中inserted/updated/deleted的数据传递到Oracle

Oracle中新增的数据通过”LOAD CACHE GROUP”同步到TimesTen

Oracle中新增的数据也可以通过SELECT, UPDATE 和 DELETE语句动态加载

如果一个表缓存到两个AWT 缺省Cache Group，缓存组之间并不相互知情，因此一个cache instance可以同时存在于两个缓存组中

语法：

create dynamic asynchronous writethrough cache group t2_awt_dyn

from t1 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

AWT Dynamic Globle (Cache Grid)

TimesTen中inserted/updated/deleted的数据传递到Oracle

Oracle中新增的数据通过”LOAD CACHE GROUP”同步到TimesTen

Oracle中新增的数据也可以通过SELECT, UPDATE 和 DELETE语句动态加载

如果一个表缓存到两个AWT Dynamic Globle Cache Group，由于缓存组之间相互保持沟通，因此一个cache instance只能存在于一个缓存组中

语法：

create dynamic asynchronous writethrough global cache group t3_awt_dyn_gbl

from t1 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

实验部分

在Oracle中创建表

$ sqlplus tthr/oracle@ttorcl

create table t1 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

create table t2 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

create table t3 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

创建DSN

[cachedb1]

Driver=/home/oracle/TimesTen/tt1122/lib/libtten.so

DataStore=/home/oracle/TimesTen/tt1122/info/DemoDataStore/cachedb1

PermSize=32

TempSize=64

LogFileSize=32

LogBufMB=32

DatabaseCharacterSet=AL32UTF8

OracleNetServiceName=ttorcl

[cachedb2]

Driver=/home/oracle/TimesTen/tt1122/lib/libtten.so

DataStore=/home/oracle/TimesTen/tt1122/info/DemoDataStore/cachedb2

PermSize=32

TempSize=64

LogFileSize=32

LogBufMB=32

DatabaseCharacterSet=AL32UTF8

OracleNetServiceName=ttorcl

创建用户

同时在cachedb1和cachedb2中执行：

create user tthr identified by timesten;

grant admin, create session, cache_manager, create any table to tthr;

创建cache group, cache grid并关联到grid

同时在cachedb1和cachedb2中执行：

ttisql−v1−e“setprompt‘cachedb1>‘”“dsn=cachedb1;uid=tthr;pwd=timesten;oraclepwd=oracle” ttisql -v1 -e “set prompt ‘cachedb1> ‘” “dsn=cachedb1;uid=tthr;pwd=timesten;oraclepwd=oracle”
ttisql -v1 -e “set prompt ‘cachedb2> ‘” “dsn=cachedb2;uid=tthr;pwd=timesten;oraclepwd=oracle”

call ttcacheuidpwdset(‘cacheadm’, ‘oracle’);

call ttcachestart;

call ttgriddestroy(‘samplegrid’,1); <- 此命令很好用

call ttgridnodestatus(‘samplegrid’);

call ttgridcreate(‘samplegrid’); <- 在任意一个TimesTen数据库中执行一次即可

call ttgridinfo(‘samplegrid’);

call ttgridnameset(‘samplegrid’);

call ttgridinfo(‘samplegrid’);

call ttgridnodestatus(‘samplegrid’);

三个表分布对应regular, dynamic, dynamic global缓存组

create asynchronous writethrough cache group t1_awt

from t1 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

create dynamic asynchronous writethrough cache group t2_awt_dyn

from t2 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

create dynamic asynchronous writethrough global cache group t3_awt_dyn_gbl

from t3 (c1 number(22) not null primary key, c2 date, c3 varchar(40));

cachedb1>

call ttgridattach(1,’member1’,’127.0.0.1’,5001);

call ttgridnodestatus(‘samplegrid’);

call ttrepstart;

cachedb2>

call ttgridattach(1,’member2’,’127.0.0.1’,5002); <- 使用不同的端口是因为两个TimesTen数据库在同一主机上

call ttgridnodestatus(‘samplegrid’);

call ttrepstart;

在两个数据库中，针对每一个缓存组插入数据

cachedb1>

insert into t1 values (1, sysdate, ‘t1 data’);

insert into t2 values (1, sysdate, ‘t2 data’);

insert into t3 values (1, sysdate, ‘t3 data’);

unload cache group t1_awt;

unload cache group t2_awt_dyn;

unload cache group t3_awt_dyn_gbl; <- unload后在TimesTen中看不到缓存数据

cachedb2>

insert into t1 values (2, sysdate, ‘t1 data’);

insert into t2 values (2, sysdate, ‘t2 data’);

insert into t3 values (2, sysdate, ‘t3 data’);

unload cache group t1_awt;

unload cache group t2_awt_dyn;

unload cache group t3_awt_dyn_gbl; <- unload后在TimesTen中看不到缓存数据

人工从Oracle中LOAD数据

cachedb1>

load cache group t1_awt where c1 = 1 commit every 10 rows parallel 10;

load cache group t2_awt_dyn where c1 = 1 commit every 10 rows parallel 10;

load cache group t3_awt_dyn_gbl where c1 = 1 commit every 10 rows parallel 10;

select * from t1;

select * from t2;

select * from t3;

unload cache group t1_awt;

unload cache group t2_awt_dyn;

unload cache group t3_awt_dyn_gbl;

cachedb2>

load cache group t1_awt where c1 = 2 commit every 10 rows parallel 10;

load cache group t2_awt_dyn where c1 = 2 commit every 10 rows parallel 10;

load cache group t3_awt_dyn_gbl where c1 = 2 commit every 10 rows parallel 10;

select * from t1;

select * from t2;

select * from t3;

unload cache group t1_awt;

unload cache group t2_awt_dyn;

unload cache group t3_awt_dyn_gbl;

通过SQL动态从Oracle中LOAD数据

cachedb1>

select * from t1 where c1 = 1;

select * from t2 where c1 = 1;

select * from t3 where c1 = 1;

select * from t1;

select * from t2;

select * from t3;

输出：

cachedb1> select * from t1; <- 没有输出，因为需要手工load

cachedb1> select * from t2; <- 有输出因为满足dynamic load条件

< 1, 2016-06-19 22:41:56, t2 data >

cachedb1> select * from t3; <- 有输出因为满足dynamic load条件

< 1, 2016-06-19 22:41:57, t3 data >

cachedb2>

select * from t1 where c1 = 2;

select * from t2 where c1 = 2;

select * from t3 where c1 = 2;

select * from t1;

select * from t2;

select * from t3;

输出：

cachedb2> select * from t1; <- 没有输出，因为需要手工load

cachedb2> select * from t2; <- 有输出因为满足dynamic load条件

< 2, 2016-06-19 22:45:12, t2 data >

cachedb2> select * from t3; <- 有输出因为满足dynamic load条件

< 2, 2016-06-19 22:46:07, t3 data >

通过SQL动态从Oracle或Cache grid中LOAD数据

cachedb1>

select * from t1 where c1 = 2;

select * from t2 where c1 = 2;

select * from t3 where c1 = 2;

select * from t1;

select * from t2;

select * from t3;

输出：

cachedb1> select * from t1;

cachedb1> select * from t2;

< 1, 2016-06-19 22:41:56, t2 data >

< 2, 2016-06-19 22:45:12, t2 data > <- 这条数据是从Oracle中dynamic load而来

cachedb1> select * from t3;

< 1, 2016-06-19 22:41:57, t3 data >

< 2, 2016-06-19 22:46:07, t3 data > <- 这条数据是从Cache Grid的另一个member: cachedb2中load而来

cachedb2>

select * from t1 where c1 = 1;

select * from t2 where c1 = 1;

select * from t3 where c1 = 1;

select * from t1;

select * from t2;

select * from t3;

输出：

cachedb2> select * from t1;

cachedb2> select * from t2;

< 1, 2016-06-19 22:41:56, t2 data > <- 对于普通的dynamic AWT，由于互不知情，因此这两条数据在两个TimesTen数据库中都存在

< 2, 2016-06-19 22:45:12, t2 data > <- 这条数据是从Oracle中dynamic load而来

cachedb2> select * from t3;

< 1, 2016-06-19 22:41:57, t3 data > <- 这条数据是从Cache Grid的另一个member: cachedb1中load而来

cachedb1> select * from t3;

< 2, 2016-06-19 22:46:07, t3 data > <- 对于global awt, cache instance只会在一个TimesTen中出现

删除缓存组并从Grid脱离关系

cachedb1>

call ttrepstop;

call ttgriddetach;

drop cache group t1_awt;

drop cache group t2_awt_dyn;

drop cache group t3_awt_dyn_gbl;

call ttcachestop;

cachedb2>

call ttrepstop;

call ttgriddetach;

drop cache group t1_awt;

drop cache group t2_awt_dyn;

drop cache group t3_awt_dyn_gbl;

call ttcachestop;

call ttgriddestroy(‘samplegrid’,1);

参考

HOWTO : Understand The Three Fundamental Types Of TimesTen Asynchronous (AWT) Cache Groups (Doc ID 1471954.1)