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Application Development on Power System (IBM i)
Application Development on Power System (IBM i)
School of Software Engineering Tongji University
HUANGJie
Syllabus
No
Subject
Hours
Abstract
Instructor
Server, Power System and Power System IBM i
Huangjie
iOS fundamental
2
4
i OS & Basic Operation
Huangjie
3
File system & object management
4
Object management concept and integrated file system
Huangjie
4
Message management
2
Message & Its management
Huangjie
5
Work management
4
Concepts of job, subsystem and library, job routing
Huangjie
6
Administration ABC
2
Security, Storage & Restore Management
Huangjie
7
Application Development
6
ILE development enviroment , RPG programming
Huangjie
8
Database Development
4
Database on IBM i
Huangjie
9
IBM i & SOA
2
SOA approach on IBM i
Huangjie
10
Case Study
2
Csae Study
Huangjie
11
Examination
2
Examination
1
Overview of IBM i
2
2017/5/22
Huangjie
2
Unit 3 IBM i Application Development
Chapter 8
Database Application Development
2017/5/22
3
Outline
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心元素
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator 基本操作
2017/5/22
4
大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心元素
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator 基本操作
2017/5/22
5
DB2 Family (ZOS, LUW, IOS) Marketshare
Source: Gartner Press Release (5/30/05)
2017/5/22
* Estimate
6
History of DB2 for i
System/38
AS/400
iSeries
Initial
SQE
Ship
1980
Integrated Relational
Database
2017/5/22
1988
SQL Interface
SQL/400
1994
DB2 for
AS/400
System i
Today
1999 2001
2006
DB2
DB2
Universal Universal
Database Database
for AS/400 for iSeries
DB2 for
i5/OS
7
DB2 on IBM i 框架
OmniFind Text Search Server for DB2 for i
OmniFind Text Search Server
Clients
IBM i OS
OS/400
i5/OS
Commands
DB2
Query
Mgr
SQL Server
Data Management
Transaction Management
ODBC
Storage Management
Resource Management
DRDA/DDM
Server
Message
s
JDBC Server
SN
A
SQL
Security
Message Management
Index Management
.
.
.
TCP/I
P
SQL
CLI
SQLJ
Applications
Other OS/400 Primitives
Native
DRDA/DD
Server
Query/400
CLI
Client
Application
DRDA
Client
Application
DB2 WebQuery for IBM i
ODBC Application
Client
JDBC
Client
Application
Or Applet
Application
ADO
Client
Application
OLE DB Application
Client
DDM
Client
IBM i DB2 Storage Engine for MySQL
Application
Ops Navigator
PHP
Application
DB2 APIs
Client Access
RPG
Application
Writes to
MySQL
Data stored in
8
DB2 for i
Accesses
Data
DB2 i Key Differences
• Not a separate product – integrated into IBM i
• i operating system uses DB2 for i and vice versa
• Not a separate charge, but a few priced options
–
–
–
–
•
•
•
•
•
DB2 Multisystem
DB2 Symmetric Multiprocessing
Query Manager and SQL Development Kit
WebQuery
Native and SQL Interfaces
Excellent interoperability and national language support
Multiple partitions and operating systems
Easier to use and maintain
Management GUI is IBM i Navigator & Director
2017/5/22
2017/5/22
9
9
DB2 for i Interfaces
Native Interfaces
SQL Interfaces
JDBC
Cobol RPG C or
C++
…
START
READ
…
…
SETLL
READ
…
…
Ropen
Rread
…
…
START
READ
…
…
SETLL
READ
…
C or C++
…
Ropen
Rread
…
2017/5/22
RPG
C or
C++
Embedded SQL
Cobol
SQL Table or View or
DDS Physical or Logical File
Distributed Data
Management (DDM
RPG
Cobol
…
SQLExecDirect
…
SQL FETCH SQLExecDirect
…
…
SQLFETCH SQLExecDirect
…
SQLFETCH
…
123 Fish, Joe
124 Olson, Ole
125 Smith, Sally
126 Johnson, John
127 Smith, Jim
Cobol
CLI
Toolbox JDBC Driver
Native JDBC Driver
Host Server (ZDA)
System i Access
Optimized APIs
System i Access
Drivers
JDBC
ODBC
.NET ADO
555
501
555
501
555
20000
20000
32000
38000
30000
Cobol
RPG
C or
C++
…
QSQPRCED…
…
QSQPRCED
…
Distributed Relational
Database (DRDA)
JDBC
ODBC
.NET ADO
C or
C++
…
EXEC SQL …
FETCH
EXEC SQL …
…
FETCH
EXEC SQL
…
FETCH
…
001
501
555
001
555
DB2 Connect Drivers
RPG
Cobol
…
QSQPRCED
…
QSQPRCED
API
Extended Dynamic
Remote SQL (XDA)
RPG
C or
C++
…
EXEC SQL …
FETCH
EXEC SQL …
…
FETCH
EXEC SQL
…
FETCH
…
JDE
SAP
…
10
大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心元素
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator基本操作
2017/5/22
11
Database Objects – Terminology
SQL
2017/5/22
IBM i
schema/collection
library
table
physical file
view
logical file
index
keyed logical file
row
record
column
field
log
journal
12
Create a Physical /Logical File with DDS
STRPDM
PFILE1
QDDSSRC
DESCRIPTION
DESCRIPTION
STRSEU
PFILE1
……
LFILE1
……
CRTPF
DATA
MEMBER
CRTLF
LFILE1
DESCRIPTION
MEMBER
2017/5/22
2017/5/22
13
13
Create a Physical File with DDS
CRTPF FILE(LIBNAME/PFNAME) SRCFILE(DDSLIB/DDSFILE)
2017/5/22
2017/5/22
14
14
Create a Logical File with DDS
CRTLF FILE(LIBNAME/LFNAME) SRCFILE(DDSLIB/DDSFILE)
2017/5/22
2017/5/22
15
15
SQL Components
Data Definition
CREATE
DROP
ALTER
Security
GRANT
SQL
REVOKE
Structured Query
Language
DYNAMIC
Data Manipulation
SELECT
INSERT
UPDATE
DELETE
2017/5/22
2017/5/22
MISCELLANEOUS
CONNECT
DECLARE
DESCRIBE
EXECUTE
PREPARE
16
16
Create Table/View with SQL
CREATE TABLE TB_WAREHOUSE (
WAREHOUSE_ID CHAR(10) NOT NULL WITH DEFAULT ,
WAREHOUSE_NAME CHAR(10) NOT NULL WITH DEFAULT ,
WAREHOUSE_STREET_1 VARCHAR(256) NOT NULL WITH DEFAULT ,
WAREHOUSE_CITY VARCHAR(40) NOT NULL WITH DEFAULT ,
WAREHOUSE_STATE CHAR(2) NOT NULL WITH DEFAULT ,
WAREHOUSE_ZIP CHAR(9) NOT NULL WITH DEFAULT '000000000',
WAREHOUSE_TAX DECIMAL(7 , 4) NOT NULL WITH DEFAULT ,
WAREHOUSE_YTD US_DOLLAR NOT NULL WITH DEFAULT ,
WAREHOUSE_STREET_2 VARCHAR(40) WITH DEFAULT NULL,
WAREHOUSE_CITYID INTEGER WITH DEFAULT NULL,
LATITUDE DOUBLE NOT NULL WITH DEFAULT 0,
LONGITUDE DOUBLE NOT NULL WITH DEFAULT 0
);
CREATE VIEW VW_WAREHOUSE
(WAREHOUSE_ID, WAREHOUSE_NAME, WAREHOUSE_STREET_1, WAREHOUSE_STREET_2, WAREHOUSE_CITY,
WAREHOUSE_STATE, WAREHOUSE_ZIP, WAREHOUSE_TAX, WAREHOUSE_YTD)
AS
SELECT WAREHOUSE_ID, WAREHOUSE_NAME, WAREHOUSE_STREET_1, WAREHOUSE_STREET_2,
WAREHOUSE_CITY, WAREHOUSE_STATE, WAREHOUSE_ZIP, WAREHOUSE_TAX, WAREHOUSE_YTD
FROM TB_WAREHOUSE WHERE WAREHOUSE_YTD > US_DOLLAR(100000);
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2017/5/22
17
Create Constraints with SQL

使用数据库约束条件的优势
– 代码重用/模块化
– 更好的数据完整性
– 更好的查询性能 - SQE 优化器可以利用约束条件产生最优的执行计划

约束条件的类型
–
–
主键 & 唯一键
参照完整性约束
• 强制实现父/子约束关系
– 检查完整性
• 确保列中只能存放有效的值
CREATE TABLE orders(
ordnum INTEGER PRIMARY KEY,
ordqty INTEGER CHECK(ordqty>0 AND ordqty<1000),
ordamt DECIMAL(7,2),
part_id CHAR(4),
CONSTRAINT ordpart FOREIGN KEY(part_id) REFERENCES parts(PartID)
ON DELETE RESTRICT ON UPDATE RESTRICT )
2017/5/22
18
Partitioned table
• WHAT
– A partitioned table is a table whose data is contained in one or more
local partitions (members).
– Range partitioning
– Hash partitioning
– Partitioning key
• WHY
– With partitioning V.S. Without partitioning
– Partitioning can also enhance the performance, recoverability, and
manageability of your database.
– Most of the CL commands that are used for members are also valid for
each partition of a partitioned table.
• WHEN
– V5R3, V7R1, V7R2, etc.
2017/5/22
19
Creation of partitioned tables
•
E.g. to partition table PAYROLL in library PRODLIB with partitioning key EMPNUM into four
partitions, use the following code:
•
•
•
•
•
•
•
CREATE TABLE PRODLIB.PAYROLL
(EMPNUM INT,
FIRSTNAME CHAR(15),
LASTNAME CHAR(15),
SALARY INT)
PARTITION BY HASH(EMPNUM)
INTO 4 PARTITIONS
•
Or, to partition PAYROLL by range, use the following code:
•
•
•
•
•
•
•
•
•
CREATE TABLE PRODLIB.PAYROLL
(EMPNUM INT,
FIRSTNAME CHAR(15),
LASTNAME CHAR(15),
SALARY INT)
PARTITION BY RANGE(EMPNUM)
(STARTING FROM (MINVALUE) ENDING AT (500) INCLUSIVE,
STARTING FROM (501) ENDING AT (1000) INCLUSIVE,
STARTING FROM (1001) ENDING AT (MAXVALUE)
2017/5/22
20
Why MQT
• To enhance query performance by using pre-calculated result
set instead of re-computing them
• Though MQT, user created summary tables may be known by
DB2 optimizer, thus can be used to enhance query
performance
• Use of MQT is transparent to users
2017/5/22
21
MQT Example
MQT1: CREATE TABLE MQT1 AS (
SELECT A.aid, T.fpgid, A.status, T.qty, T.price, T.disc, T.qty*T.price as value
FROM Trans T, Acct A
WHERE T.faid=A.aid
AND T.disc>0.1)
DATA INITIALLY DEFERRED REFRESH DEFERRED
ENABLE QUERY OPTIMIZATION
MAINTAINED BY USER
Q1: SELECT A.aid, A.status, T.qty*T.price *(1-T.disc) as amt
FROM Trans T, PGroup P, Acct A
WHERE P.pgid=T.fpgid and T.faid=A.aid
AND T.price> 100 AND T.disc>0.1
AND P.pgname>’TV
Resulting New Query:
SELECT A1.aid, A1.status, A1.value *(1-A1.disc) as amt
FROM MQT1 A1, PGroup P
WHERE P.pgid=A1.fpgid
AND A1.price> 100
AND P.pgname>’TV
2017/5/22
22
大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心特征
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator基本操作
2017/5/22
23
Stored Procedure
An SQL "Program" that contains:
• HLL Program with or without embedded SQL
• SQL Language
• Stored Procedure Created by CREATE PROCEDURE
• Can pass parameters
• Can return parameters, result set
• Widely used in Client / Server applications to reduce
traffic
OR
2017/5/22
24
Stored Procedure
STORED PROCEDURE
CREATE PROCEDURE SPName (IN DataType Var1,
Out ….. )
LANGUAGE SQL
BEGIN
INSERT INTO TableName VALUES(Var1);
……
END
存储过程：将常用的或很复杂的工作,预先用SQL语句写好并用一个指定
的名称存储起来,那么以后要叫数据库提供与已定义好的存储过程的功能
相同的服务时,只需调用execute,即可自动完成命令。
2017/5/22
25
Trigger
Triggers:
Application-independent
•Enforce business rules
•Written once; used by many
•Enforce data validation and audit trail
Activated by database manager when
•Preserve data consistency
operations performed on database
Triggers versus Stored Procedures
•'Fired' by specified database
•Triggers invoked by database events
operations and take action written
•Stored procedures invoked by application
in trigger
CALL
•Interface-independent
When a new order is inserted or updated, a trigger is fired:
• Trigger retrieves information about order and customer
• A confirmation fax is automatically sent
2017/5/22
26
Trigger Example
Client Application
Communication
Line Data Flow
Database Server
with No Triggers
TABLE1
UPDATE TABLE1 . .
SELECT TABLE2. . .
TABLE2
UPDATE TABLE2 .
TABLE3
INSERT TABLE3 . .
Client Application
Communication
Line Data Flow
UPDATE TABLE1. . .
Database Server
With Triggers
当在一个物理文件上加载
触发器时，必须定义三个
属性。第一是定义引起触
发器运行的事件，这类事
件可以是在文件中插入、
更新或删除一条记录；第
二是定义触发器在什么时
候，即事件之前还是之后
启动；第三是定义要运行
的特定的程序，触发程序
是用户提供的基于任何
IBM i高级语言的程序。
TABLE1
TABLE2
TABLE3
SELECT TABLE2
UPDATE TABLE2
INSERT TABLE3
.....
Trigger Program
2017/5/22
27
Trigger Mode: DB2ROW versus DB2SQL
Row Level、Statement Level、Column Level
2017/5/22
28
将业务逻辑移入数据库—Trigger

用户可以使用触发器对新增加的数据或者被修改的数据进行业务处理
–
–
–

DB2保证触发器总是会被执行
触发器执行与用户所使用的接口无关
可以使用触发器在数据写入数据库前对其进行转换
DB2 for i 的触发器的支持
–
–
前触发/后触发: 插入，更新和删除 (最多 300 个触发器可以被一次操作触发)
SQL 和 外部(ADDPFTRG) 触发器
• 列级别，语句级别，以及Instead Of trigger只能使用SQL触发器
CREATE TRIGGER audit_salary
AFTER UPDATE ON employee(salary)
REFERENCING NEW AS n
REFERENCING OLD AS o
FOR EACH ROW
WHEN (n.salary - o.salary >= 5000)
INSERT INTO audit
VALUES(n.empno, n.deptno, n.salary,current timestamp)
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29
The Need for Large Objects (LOBs)
• Provide support for Web-based multimedia applications
• Provide a built-in data type that can store a large amount of data
• There are three different types of data:
–
–
–
2017/5/22
BLOB (Binary Large Object): For scanned documents, digital images, and so forth
CLOB (Character Large Object): Large character string data type
DBCLOB (Double Byte Character Large Object): Large double-byte character string data type
30
User-Defined Types – Example
INTEGER
DOUBLE
TIMESTAMP
VARCHAR
CLOB
SMALLINT
*
/
+
SUM
AVG
DECIMAL
DECIMAL
CHAR
SUBSTR
POSSTR
CREATE DISTINCT TYPE
US_DOLLAR AS DECIMAL(11,2)
WITH COMPARISONS
CREATE DISTINCT TYPE
EURO AS DECIMAL(11,2) WITH
COMPARISONS
2017/5/22
BLOB
DATE
DAYS
MONTH
US_DOLLAR
DECIMAL
US_DOLLAR
EURO
DECIMAL
EURO
TIME
MINUTE
HOUR
CREATE DISTINCT TYPE
us_dollars AS DECIMAL(11,2);
CREATE DISTINCT TYPE
can_dollars AS DECIMAL(11,2);
CREATE TABLE products (
prod_id
CHAR(5),
prod_desc
VARCHAR(50),
prod_weight DECIMAL(11,2),
usa_price
US_DOLLARS,
can_price
CAN_DOLLARS,
product_image BLOB(1M)
)
31
User-Defined Functions – Examples
FIND_PICTURE(
,SLIDE_SHOW)
Large Object
Search
15,
78, 54, 67, 67, 94,
99, 53, 47, 87, 72,
ARRAY_AVERAGE(CLASSROOM_MARKS) 34, 63, 54, 59, 82
Type Cast Functions:
Built-in Functions:
SQRT()
TAN()
2017/5/22
EXP()
LOG()
SIN()
COS()
RAND() POWER()
MONEY()
DOLLAR()
32
大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心特征
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator 基本操作
2017/5/22
33
IBM i as “DB Server”
IBM i
IBM i
JDBC
CLI*
Embedded
DRDA
Native/DDM
AIX
JDBC
DRDA
iSeries Toolbox JDBC
DB2 Connect
DB2 Information Integrator
Linux
JDBC
ODBC
DRDA
iSeries Toolbox JDBC
DB2 Connect
iSeries ODBC
DB2
for
IBM
i
Windows
JDBC
ODBC
OLE DB
.NET
DRDA
iSeries Access
DB2 Connect
DB2 Information Integrator
* OS/400 PASE only supports CLI
DB2 for IBM i有多种编程访问接口，既有基于主机方式的接口，又有基于客户机/服务器方式的访问接口
2017/5/22
34
DB2 for i Interfaces
Native Interfaces
SQL Interfaces
JDBC
Cobol RPG C or
C++
…
START
READ
…
…
SETLL
READ
…
…
Ropen
Rread
…
…
START
READ
…
…
SETLL
READ
…
C or C++
…
Ropen
Rread
…
2017/5/22
RPG
C or
C++
Embedded SQL
Cobol
SQL Table or View or
DDS Physical or Logical File
Distributed Data
Management (DDM
RPG
Cobol
…
SQLExecDirect
…
SQL FETCH SQLExecDirect
…
…
SQLFETCH SQLExecDirect
…
SQLFETCH
…
123 Fish, Joe
124 Olson, Ole
125 Smith, Sally
126 Johnson, John
127 Smith, Jim
Cobol
CLI
Toolbox JDBC Driver
Native JDBC Driver
Host Server (ZDA)
System i Access
Optimized APIs
System i Access
Drivers
JDBC
ODBC
.NET ADO
555
501
555
501
555
20000
20000
32000
38000
30000
Cobol
RPG
C or
C++
…
QSQPRCED…
…
QSQPRCED
…
Distributed Relational
Database (DRDA)
JDBC
ODBC
.NET ADO
C or
C++
…
EXEC SQL …
FETCH
EXEC SQL …
…
FETCH
EXEC SQL
…
FETCH
…
001
501
555
001
555
DB2 Connect Drivers
RPG
Cobol
…
QSQPRCED
…
QSQPRCED
API
Extended Dynamic
Remote SQL (XDA)
RPG
C or
C++
…
EXEC SQL …
FETCH
EXEC SQL …
…
FETCH
EXEC SQL
…
FETCH
…
JDE
SAP
…
35
Native数据访问和SQL数据访问
• RPG 行层级访问
– 很好的单记录 / 顺序读取的 IO 性
能
– 当处理复杂业务逻辑时较难编程/
维护
– 不易扩展
• SQL
36
– IBM最先进的查询优化器继续带
来更好的 性能
– 对复杂 业务需求 的快速交付
– 优秀的扩展性
– DB2 for i 数据存取的 发展方向
– 商业标准 的数据处理语言
– 开放性 带来更好的可移植性以及
更好的人才储备
– 增强的 数据完整性
Native向SQL迁移的主要考虑因素
传统模式
SQL
对象定义
DDS
SQL DDL
数据建模
物理文件/逻辑文
件
表/视图/索引
数据访问
RPG/COBOL 行
级别访问
嵌入式/动态SQL
语句表级别访问
RPG程序员
数据库优化器
查询计划决定
者
Native记录级别访问和SQL的典型应用场景
 推荐使用SQL开发新的应用，但是行级别访问不会消亡
 选择SQL或者行级别访问依赖于应用场景以及应用架构
• SQL的优势
–
–
–
–
以集合方式处理数据
大量的SELECT操作
复杂的业务逻辑
SQL提供强大的内建函数
与功能
 记录级别访问的优势
– 在线交易类型的处理
– 对单条数据处理，读/写/
更新
– 内建的对称多处理保证业
务可扩展性
2017/5/22
37
传统记录级别访问
38
以数据为核心的SQL编程
39
大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心特征
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator基本操作
2017/5/22
40
Five Factors of DB Performance
• Workload
– OLTP, OLAP, ad-hoc queries, system commands
• Can fluctuate drastically
• Throughput
– Overall capability to process data
• CPU speed, I/O speed, parallel capabilities
• Resources
– Hardware- and software tools
• Database kernel, disk storage, RAM, cache, microcode
• Optimization
– Query optimization is primary accomplished internal
– SQL formulations, index strategy and database parameter
• Contention
– Condition, where two or more components are attempting to use a
single resource in a conflict way
– As contention increases, throughput decreases
2017/5/22
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Various Factors of Optimization
Server attributes
Server configuration
Version/Release/Modification
Level
Server performance
SMP
Job, Query attributes
The
Plan
Table sizes, number of rows
SQL Request
Static
Dynamic
Extended Dynamic
Interfaces
2017/5/22
Database design
Views and Indexes (Radix, EVI)
Work
management
42
SQL Optimizer
• Why?
– Improved Database performance
• Identify technique used to implement query
• Selects most efficient technique
• Access Plan
– Internal structure defining method to process SQL
statement
– Created during SQL parse, syntax check
• Optimal access method selection based on
– Implementation cost
• SQL Statement
• Current state of the database
–SQLIndexes/File
Sizes
Statement
Optimization
Bind
Access
Plan
Database
2017/5/22
43
SQL Packages
• IBM i Extended Dynamic SQL Support
–
–
–
–
–
Control structures used to execute SQL statements
Access Plans stored in *SQLPKG object
Improves Performance
IBM i CL commands : CRTSQLPKG, DLTSQLPKG
Dynamic re-optimization
• File size
• New/Deleted indexes
First time
SQL
Statement
Optimization
Database
Subsequent
SQL
Statement
Access
Plan
Bind
Access Plan
Validate
SQL Package
Open Data
Path (ODP)
Database
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Parallelism
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45
Indexing
• Radix Index
• Encoded Vector Index
• When will be indexes created?
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46
Index Strategy
• DB2 for i has two types of indexing technologies
– Radix Index
– Encoded Vector Index
• Each type of index has specific uses and advantages
• Respective indexing technologies complement each other
• Indexes are used for both statistics and implementation choices
• Indexes provide RRN/Rids and/or data (Index Only Access Plans)
• Indexes are scanned or probed
– Probe can only occur on contiguous, leading key columns
• Indexes support both relationships between tables (Referential Integrity) as
well as support local selection, joining, grouping and ordering
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Radix Index
Key values are compressed
Common patterns stored once
Unique portion stored in "leaf" pages
Positive impact on size and depth of the "tree"
Algorithm used to find values
Binary search
Very efficient process to find a unique value or small range of values
Modified to fit the data structure
Used to materialize a bitmap or relative record number (RRN)
Maintenance
Index data is automatically spread across all available disk units
Tree is automatically "rebalanced" to maintain an efficient structure
No "index reorganization" required
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48
Radix Index
ROOT
Database Table
001
ARKANSAS
002
MISSISSIPPI
003
MISSOURI
004
IOWA
005
ARIZONA
…
…
Test
Node
ADVANTAGES:
 Very fast access to a single key
value
 Also fast for small, selected
range of key values (low
selectivity)
 Provides order
2017/5/22
IOWA
004
AR
IZONA
005
MISS
ISSIPPI
002
OURI
003
KANSAS
001
DISADVANTAGES:
 Table rows retrieved in order of key values
(not physical order) which equates to
random I/O’s
 No way to predict which physical index
pages are next when traversing the index
for large number of key values
49
Encoded Vector Index (EVI)
Index object for delivering fast data access in analytical query and
reporting environments
Advanced technology from IBM Research, that is a variation on bitmap
indexing
Complement to radix index (keyed logical file or SQL index)
Easy to access data statistics improve query optimizer decision making
Used to materialize a bitmap or relative record number (RRN) list
Easy to maintain
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50
Encoded Vector Index (EVI)
Object type is File, subtype is LF
EVI is composed of two parts...
SYMBOL
TABLE:
Key Value
Alabama
Alaska
Arizona
California
Colorado
...
Wisconsin
Wyoming
VECTOR:
Code Count
1
2
3
4
5
...
49
50
1000
450
5000
10000
6500
...
340
2760
Only
Codes
1
17
5
9
2
7
49
49
5
...
Row
1
2
3
4
5
6
7
8
9
...
Symbol table contains information for each distinct key value. Each key value is
assigned a unique code
Code is 1, 2, or 4 bytes - depending on number of distinct key values
Rather than a bit array for each distinct key value, the index has one array of codes
(a.k.a., the Vector)
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51
Encoded Vector Indexing
New type of index that can significantly improve performance, especially for star schema
10% to 30% faster index builds
1/3 to 1/16 the size
1/2 the time for index scans
350 GB Table Query
1/3 the time for bit map generation
4 Table Join (Star Schema)
Symbol Table
Arizona
Arkansas
......
Virginia
Wyoming
Code First
Row
1
1
2
5
37
38
1222
7
Last
Row
80005
99760
30111
83000
Count
300
5000
7300
Time (Minutes)
Key Value
350
340
2760
13
12
28
2
17
250
200
150
100
Vector
1
4.8 Hours
38
2
26
33
29
Minutes
50
3 Min.
0
Row 1 Row 2
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....
Pre EVI
(S40-12)
740-12
EVI-Stage 2
740-12-V4R4
52
ENCODED VECTOR INDEX (EVI)
Given an EVI on table EMPLOYEE keyed on STATE...
Set bits in bitmap
or
return RRN list
...WHERE STATE = ‘ILLINOIS’
Symbol Table
Binary
search
symbol
table
for
key(s)
and
code(s
)
Key
Code
ARIZONA
ARKANSAS
CALIFORNIA
COLORADO
ILLINOIS
IOWA
KANSAS
MISSISSIPPI
...
1
2
3
4
5
6
7
8
...
Index for delivering fast data access in
analytical and reporting environments
2017/5/22
Scan
vector
for
code(s)
Vector
Bitmap
1
17
5
9
2
7
49
49
5
.
.
.
0
0
1
0
0
0
0
.
.
.
.
0
1
.
.
.
.
.
.
.
Row
1
2
3
4
5
6
7
8
9
...
53
Index ANDing / ORing Example 1
State
Workdept
EVI
EVI
Intermediate
RRN list
3
5
10
15
1000 AND
1005
(Merge)
1007
3001
3050
State
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SELECT *
FROM EMPLOYEE
WHERE STATE = ‘MINNESOTA'
AND WORKDEPT IN ( 'B01', C01, 'E01')
Intermediate
RRN list
Final
RRN list
3
7
10
27
1000
1010
2035
3001
4100
3
10
1000
3001
Workdepts
Represents
all the local
selection
Merge/Skip Sequential Plans
54
Index ANDing / ORing Example 2
State
Workdept
EVI
Radix
SELECT *
FROM EMPLOYEE
WHERE STATE = ‘IOWA'
OR WORKDEPT IN ( 'B01', C01, 'E01')
Intermediate
Bitmap
Intermediate
Bitmap
Final
Bitmap
0
0
0
0
0
0
0
1
1
1
0
1
0
0
0
0
OR
0
0
0
0
(Merge)
0
0
0
1
1
.
.
.
.
.
.
.
.
.
1
1
1
.
.
.
0
0
State
Workdepts
.
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.
.
.
.
Represents
all the local
selection
55
Indexing Strategy
• You must create some indexes
– Statistics
– Implementations
• Proactive
– Create indexes over primary, foreign key columns and dependent
columns
– Create indexes for selection and joining
– Create indexes for selection, grouping and ordering
• Reactive
– Create indexes based on optimizer feedback
• Visual Explain
• Database monitors
• Joblog messages
• Create indexes based on optimization, implementation,
system resources and performance
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DB2 for i
cardinality
The number of elements in a set.
• High cardinality = large distinct number of values
• Low cardinality = small distinct number of values
In general…
• A radix index is best when accessing a small set of rows and the
key cardinality is high
• An encoded vector index is best when accessing a set of rows
and the key cardinality is low
• Understanding the data and query are key
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DB2 for i
selectivity The number of records (expressed as a
percentage of total records possible) that will be returned
returned given a predicate or set of predicates.
• High selectivity = large number of records returned
• Low selectivity = smaller number of records returned
In general…
• A radix index is best when accessing a small set of rows,
selectivity of predicates is low
• An encoded vector index is best when accessing larger set of
rows, selectivity of predicates is high
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Indexing Strategy – Proactive Basic Approach
Radix Indexes
• Local selection columns
Minimum
• Join columns
• Local selection columns + join columns
• Local selection columns + grouping columns
• Local selection columns + ordering columns
• Ordering columns + local selection columns
Encoded Vector Indexes
• Local selection column (single key column of low cardinality)
• Join column (data warehouse - star or snowflake schema)
EVIs on join columns of my large fact tables, especially
foreign key
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大纲
•
•
•
•
•
•
DB2 for IBM i 全局概览
DB2 for IBM i 核心特征
DB2 for IBM i 高级功能
DB2 for IBM i 数据库访问
DB2 for IBM i 性能调优
IBM i Navigator基本操作
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How Do I Start the IBM i Navigator?
•
It’s simple! If the system is up, the system
database is up
•
Support for multiple database instances per
server (since V5R2)
–
•
Allows you to work on multiple databases on
a single system
–
–
•
61
Requires special setup of Independent
Auxiliary Storage Pools (IASPs)
Expand each database to work at that level
No need to "switch" back and forth when
working with multiple databases on a specific
system
See Relational Database Directory entries
Explorer-like Interface
Folders under each Schema (Library), for each object type.
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Managing the Schema – Seeing is believing
•
•
•
•
•
•
63
A list of database objects in the schema
is nice, but...
Now I understand this App
(no wonder we didn't understand it!)
Easily see how decisions could affect
the schema
– I already have five indexes over that
table?
– Should I remove one?
– That view is really over seven
tables?
– I didn't know we had RI defined
over those
e.g. application designer creates a test
database using the picture and brings it
to me for sign off
Maps stored on i5/OS
Advanced, graphical version of DSPDBR
Database Navigator
Can easily see
relationships for existing
schemas, including:
Referential Constraints
Indexes
Views
Journals
Primary/Unique Keys
Aliases
Check Constraints
Triggers
UDRs
Table Partitions
MQTS
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Database Navigator – UDRs
User-Defined Relationships
can be defined to document
links
•
Not SQL constructs
•
A way to depict applicationspecific relationships
65
Creating a Schema (called Library pre-V5R3)
•
CREATE SCHEMA MYSCHEMA;
– Organizational construct
– Library/Folder
•
A stored procedure is shipped with
i5/OS that can create sample schemas
– CALL
CREATE_SQL_SAMPLE(‘CORPDATA’);
– Contains tables (including sample data),
views, aliases, indexes, and RI
– CORPDATA is used in the SQL manuals
and labs
67
Database Object creation
•
Create database objects with no storage
considerations (including tables!)
•
Browse function for reusing existing
column definitions
•
Robust Alter Table support
– No need for special utilities
How do I rebalance indexes?
- it’s simple! The database does it for me.
New index create options for specifying
parallel degree and page size
68
Run SQL Scripts
•
Create/save scripts for repetitive tasks
•
Both SQL statements and CL commands
•
See output for SQL queries
•
Call stored procedures with result sets
and/or OUTput parameters and launch
iSeries System Debugger
•
Do Visual Explain on queries, for
performance analysis and tuning
•
Syntax error highlighting and font chooser
•
SQL Assistant for building SQL statements
•
SQL state errors in message box, including
second level text
•
Prompting of CL commands
•
Ignore drop error messages
69
Run SQL Scripts
•
•
•
•
•
•
•
•
•
•
•
CHK SQL portability
New
V6R1
Save to SRCPF
Save to IFS file
Save to UTF8 file
Save output to Spread sheet
Toggle output to use display
heading
Undoc result window
Launch directly from SQL IFS object
Print results
Font applies to output
Save as for output
70
Show SQL statement from create dialogs
•
SQL statement is recorded as you fill in
dialog
•
Option to show the SQL statement
being built
•
Great for learning SQL syntax
•
Allows for statement customization
71
Keeping schema source
• DDS - source files - (object source
file info maintained)
• SQL - Run SQL Statements PC or IFS
files
• SQL - RUNSQLSTM source files (object source file maintained)
72
Generate the SQL
– Regenerate SQL CREATE/ALTER statements directly from the existing objects
• Helpful for when the original statements are no longer available
• Teach programmers about SQL syntax of objects
See what the SQL form of my DDS-created files would be like
Include generating short
names of objects
Do not generate RI and
triggers for tables
Include SET OPTIONS
statement
V6R1: Now supported at
folder level versus
schema or object
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73
Journaling
•
•
74
Default journal automatically created and
started when creating a schema
Journal receivers contain journal entries for
recovery
Table Description
Answers questions like: How big is this
table/file getting anyway?
– Works for indexes and views too!
75
How do I synch up my DB and OS userids?
it’s Simple! Group and user authorizations are
managed by operating system
•
•
•
•
•
•
76
SQL syntax maps to i5/OS security types
Column level security
Program vs. object level security
Views
Exits
Auditing
Database Loading
•
Parallel Data load (Import)– Wizard based on CPYFRMIMPF and CPYTOIMPF CL
commands
–
77
Show Command displays command syntax in Run SQL Scripts
Constraint Repair
• Works for both check constraints
and referential integrity constraints
• Show problem rows in table
• Able to update column values or
delete entire rows
• Quick access to check constraint
definition for check constraint
repair
• Quick access to parent table rows
for RI constraint repair
78
Reorganize Table Progress Monitoring
•
New reorganize table options:
– Allow suspend (cancel)
– Allow online access
– Allow changes
– Influence when to rebuild access paths
•
79
Allow reorganize to be suspended and
resumed later
Reorganize Table --- Monitoring the Progress
•
Show percent complete of reorganize
and status of indexes as they are
reorganized
•
Attach to an already-running
reorganization to see progress
•
Ability to Suspend an ongoing reorg –
even after disconnect of client
80
Manage Index Rebuilds
2017/5/22

Manage index re-creation after Reorgs,
Database Restores, etc
• Priority Adjusting
• Monitor Progress

GUI version of EDTRBDAP system
command
81
Health Center
•
Overview to see database object counts
by category
•
View database wide or schema specific
– % wildcards can be used
•
Capture to history file
•
View history of counts for trending
•
Environmental Limits
82
New
V6R1
Environmental Limits
• DB limits within Jobs
• Lob Locators
• Active Descriptors
• Max SQL STMT Size
2017/5/22
83
Health Center
•
Size and Design Limits views
– Size limits are things that change by
normal operations
– Design limits are things that change by
application design
•
View database wide, schema specific or
by object name
– % wildcards can be used
•
Categorized by limit type, includes
system limit!
•
Status indicator for “within percent of
limit”
– Changeable threshold
•
•
84
Capture to history file
View history of limits for trending
Current SQL for a Job
•
•
Launched from Databases folder
Find a job for which someone is
reporting problems
All columns are sortable
Shows schema name and
program name, service program
name, or package name, IP
Address,
Can view job log, Show SQL
Details, or end job
Edit SQL launches SQL statement
into Run SQL Scripts window, or
can go directly to Visual Explain
Can See Environment, Statement
And Resource Details
Refresh allows for monitoring
•
•
•
•
•
•
85
Work Management for Database Jobs
• Work with jobs
– Find a job for which someone is reporting problems
– Customize list by user, job information, and column filtering
– Find SQL statement run by the job
86
Who’s Got Those Table Rows Locked?
• See what jobs have which rows locked for a given table
– Shows the row number locked
– Current User column shows “real” userid if from a client
– Job information provided
– Viewing of row locks also available in Work Management folder for
jobs and threads
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Live Analysis – Index Advisor
Want DB2® to help with your Indexing Strategy?
 New system-wide repository of DB2 Advised Indexes
– System view makes it easier to create index with biggest impact
– Gauge benefits of index creation based on frequency, last occurrence, common keys
– Available at the database, schema, or individual table level
 Enhanced Index Advice (SQE-Only)
 Ability to view SQL statements that caused index advice (SQE-Only)
 Index Advice Condenser to ease DB2 Performance tuning
– http://www-128.ibm.com/developerworks/db2/library/techarticle/dm-0701forstie/
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88
Live Analysis – SQL Plan Cache
Easy analysis of current SQL
workloads …
 Without overhead of database
monitor
 Advanced filtering to quickly
narrow focus to the most
interesting SQL
– By number of executions
– By DB2 object
– …
 Easy access to Visual Explain
for detailed analysis
 Archive capability into
snapshot for future
comparisons
 SQE-Only
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SQL Performance Monitor Toolset
Have an existing application and want to
capture the SQL activity and analyze it?
•
Start / Stop database monitor
– Pre & Post-Filtering
– Summary or Detailed
– Import data from other systems
•
Areas to watch:
–
–
–
–
•
•
Index advised
Full opens vs. pseudo opens
Access plan rebuilds
Index creates
Recommended during application
tuning & problem determination
Keep a baseline monitor run for comparison
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SQL Performance Monitor Filtering
 Minimize system-impact by reducing amount of data collected
–
–
–
–
Collect data for a specific user
Collect data for a collection of jobs (QZDASO*)
Collect data for longer-running SQL requests
…
 Enables quicker analysis & identification of SQL performance bottlenecks
 Post-Filtering available for Visual Explain interface
2017/5/22
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SQL Performance Monitor Analysis
• Summary view to more simply decide, if the monitor has attributes that
require deeper analysis
• Integrated analysis with ability to launch other performance tools from current
analysis view
Dashboard Summary
Drill-Thru Analysis
2017/5/22
92
SQL Performance Monitor Comparison
•
Want to know if an application change,
system change or PTF altered your DB2
performance?
– Compare current SQL performance
“profile” with archived monitor data
– See if the optimizer’s implementation of
an SQL statement has changed
– Can be long-running operation for large
database monitor collections
– Can do High level compare of two or
more monitors
93
Analyze SQL Performance Monitors with Visual Explain
•
Select existing detailed SQL
Performance Monitor
•
Show list of SQL statements captured by
the monitor
•
Can import monitor data from other
systems
•
Can narrow down analysis with postfilters
94
Visual Explain
•
Active window - Look at DB objects (indexes,
constraints, etc.) involved
•
Attributes show all the settings that impact
query optimizer
–
–
•
Icon Highlighting to speed analysis
–
–
•
95
Labels include optimizer’s estimates
SQE plans show decomposed SQL statement
for each operation
Expensive nodes
Index Advised nodes
Debug messages help bridge to picture
VE Explain While Running
• Allows you to see actual runtime feedback in VE diagram
THIS IS VERY COOL!!
96
New
V6R1
Index Advisor
• Advisor shows indexes that would help specific query (if any)
• Use advice along with
Index Analyzer for the table
to determine if index would
be helpful
• Create button prompts
Create Index dialog with
recommended columns
pre-filled
2017/5/22
97
Statistics
•
Advisor in Visual Explain shows statistics that
would help specific query
•
How do I run statistics?
–
•
98
It’s simple! Statistics automatically
created/maintained by database
Cardinality, Most common values
Evaluating your Indexes & MQTs
Is an Index or MQT providing value?
•
•
Launch Evaluators by right-clicking on table and select Show Index or MQT
Scroll Right to find the interesting query optimizer usage statistics
–
–
•
Stats updated for all query interfaces – MQTs are SQL-only
Includes all objects the optimizer evaluates whether created by DDS or SQL
Index Evaluator available on V5R2 & V5R3 via PTF – statistics not updated until the PTFs are applied
2017/5/22
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Enhanced Index management
From Index Folder I can now:
• See Owning Index Name
• See/ Reset Query Usage Stats
• Show Statements from plan cache that use this index
2017/5/22
New
V6R1
100
Analyze Performance of SQL Programs & Packages
•
Explain SQL is equivalent to PRTSQLINF CL
command
•
Can Explain SQL for functions, procedures,
triggers, and packages
•
Can Explain SQL for programs by going
down the File System folder
•
How do I rebind my application packages?
– It’s simple! The database does it for you
automatically.
10
1
SQL and External Triggers
• Easily create External and SQL Triggers with new wizard
• Also added Instead of triggers over views
2017/5/22
102
Stored Procedures
• Easily create External (including Java) and SQL stored procedures
• A List of example SQL statements makes creating SQL procedures easier
2017/5/22
103
SQL Graphical Debug
• Starts with SQL *SOURCE Debug View
– Specifying DBGVIEW=*SOURCE on the SET OPTION clause in your SQL
procedure, function, or trigger
– Specify a *SOURCE value for DBGVIEW parameter on the RUNSQLSTM
(Run SQL Statements) CL command
• Graphical iSeries System Debugger
– Part of the Toolbox for Java
– Typical debugger capabilities
– Can debug SQL procedures, functions, and triggers that run on System
i5 family
2017/5/22
104
iSeries System Debugger - example
2017/5/22
105
Ease of Database Management
Typical DBA Tasks
DB2 for i5/OS
Manage DASD Space Allocation
Automated
Review Table Space Allocations & Extents
Automated
Review & Balance Indexes
Automated
Application Rebinding
Automated
Maintain Database Integrity
Automated
Update Database Statistics
Automated
Synchronized OS & DB User Security
Automated
Reload Data for Hardware & Software Upgrades
Automated
Load Data into Database
System i Navigator
Build and Manage DB Backup & Recovery
System i Navigator
Create & Review Indexes for Tables
System i Navigator / Automated Index Advisor
Performance Analysis & Tuning (DB & System)
System i Navigator
Create and Maintain DB Schema
System i Navigator
& 3rd Party Tools
Automated DB Performance Profiling
3rd Party Tools
Advanced DB Performance Analysis & Tuning
System i Navigator
3rd Party Tools
Data Replication & Consolidation
Multiple IBM & 3rd Party Products
Warehouse common schema
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
TB_WAREHOUSE
TB_TRANSACTION_IDENTIFICATION
TB_STOCK (Partitioned Table)
TB_STATE_IDENTIFICATION
TB_ORDERLINE
TB_ORDER (Partitioned Table)
TB_NEWORDER
TB_ITEM_CATEGORY_IDENTIFICATION
TB_ITEM
TB_INCOME_RANGE
TB_HISTORY (Partitioned Table)
TB_ETHNIC_GROUP
TB_DISTRICT
TB_CUSTOMER_ACCOUNT
TB_CUSTOMER (Partitioned Table)
TB_AGE_GROUP
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Questions & Answers?
2017/5/22
108