Internals of Derby - Apache DB Project - The Apache Software

61 Pages·2005·0.26 MB·English

by  D D

In t er n al s o f D er b y
An Open Sour ce Pur e Java Relat ional Dat abase
Engine
Dan i el Joh n Deb r u n n er
STSM – IBM Dat a Managem ent
(1.1 2004/ 09/ 20)
In t r o d u ct i o n
Af t er a q u i ck ov er v i ew of Der b y, I w i l l

p r esen t som e of t h e i n t er n al s of t h e
t ech n ol og y.
In t er n al f eat u r es w i l l b e cov er ed at a

h i g h l ev el , i n cl u d i n g som e of t h e
l esson s l ear n t ov er t h e year s.
Pl ease f eel f r ee t o ask q u est i on s as w e

g o.
Th i s i s n ot a com p l et e g u i d e t o t h e

i n t er n al s of Der b y, f or t h at r ead t h e
sou r ce cod e!
A g en d a
Der b y Ov er v i ew

Syst em i n t er n al s

Lan g u ag e i n t er n al s

St or e i n t er n al s

A p ach e D er b y
IBM con t r i b u t ed t h e Cl ou d scap e

sou r ce cod e t o t h e Ap ach e Sof t w ar e
Fou n d at i on as Der b y
Ap ach e DB p r oj ect sp on sor ed Der b y

i n t o i n cu b at i on at Ap ach e
Der b y n ow u p an d r u n n i n g at Ap ach e

Derby is an ef fort undergoing incubation at the Apache

Softw are Foundation. Incubation is required of all
new ly accepted projects until a further review indicates
that the inf rastructure, com m unications, and decision-
making process have stabilised in a m anner consistent
w ith other successful ASF projects. While incubation
status is not necessarily a ref lection of the
completeness or stability of the code, it does indicate
that the project has yet to be fully endorsed by the ASF.
Br i ef Hi st o r y
1996 – Cloud scap e, Inc st ar t up – Oak land,

CA
1997 – JBMS 1.0

Ap r 1999 – Cloudscap e 2.0

Dec 1999 – Acq uir ed b y Inf or m ix Sof t w ar e

June 2001 – Cloudscape 4.0

July 2001 – Acq uir ed b y IBM

Dec 2001 – IBM Cloud scap e 5.0

2003 – IBM Cloud scap e 5.1, 5.1FP1 & FP2

Signif icant IBM use as a com ponent
➢
August 2004 – Op en Sour ced as Der b y at

ASF
D er b y Em b ed d ed En g i n e
Pu r e Java

Em b ed d ed Dat ab ase

Sm al l Foot p r i n t

St an d ar d s Based

Com p l et e Rel at i on al Dat ab ase En g i n e

Pu r e Jav a
Com p l et el y w r i t t en i n Jav a

Su p p or t s J2SE 1.3/ 1.4/ 1.5 w i t h si n g l e

j ar
Ru n s an yw h er e – Li n u x, Wi n d ow s,

MacOS, Sol ar i s, i - Ser i es, z- Ser i es
Dat ab ase f or m at p l at f or m

i n d ep en d en t t oo
Em b ed d ed D at ab ase
Dat ab ase en g i n e b ecom es i n t eg r al

p ar t of t h e Jav a ap p l i cat i on
No ad d i t i on al p r ocess

Ap plicat ion's JDBC calls now j ust r esult in
➢
m et hod calls w it hin sam e JVM
Ju st a Jar f i l e t o t h e ap p l i cat i on

Dat ab ase i n vi si b l e t o en d u ser of

ap p l i cat i on
Em b ed d ed w i t h A p p l i cat i o n
Java Virt ual Machine
- Dat abase only accessible f r om
Applicat ion single JVM
- Java/ JDBC only
- No net w ork connect ivit y
JDBC
- Typically is single applicat ion
per JVM (but could be m ult iple)
Der by engine
Database(s)
on disk
Em b ed d ed i n A p p l i cat i o n
Ser v er
Java Virt ual Machine
App Server
Web- client s
App AApppp App
It’s just an em bedded use of
JDBC
Derby w here t he applicat ion
server is t he applicat ion
Derby engine
Database(s)
on disk