internal tables (1)

8/19/2019 Internal Tables (1)

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INTERNAL TABLE


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Kaavian Systems02-Sep-09

Defnition

♦ Snap-shot o a database

♦ Dynamic Sequential dataset

♦

All eco ds ha!e same st uctu e " #ey ♦ E$ist only du in% un time o a p o% am

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&u pose

♦ 'o p ocessin% la %e !olumes o data

♦ 'o educin% database hits

♦ 'o o mattin% data to ft the equi ements o the

application

E$ample (

So tin%) t uncatin%) concatenatin%

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Att ibutes o Inte nal Table

♦ Line type

♦ *ey

♦ Table type

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Line Type

♦ It can be any data type

♦ Data type is no mally st uctu e

♦ Each component o a st uctu e is a column in

inte nal table

♦ Line may also be elementa y o anothe inte nal table

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*ey

♦ Standa d *ey +De ault #ey,

♦ se defned #ey

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Table Type

♦ It dete mines ho. ABA& .ill access indi!idualtable ent ies/

♦ Types

Standa d table 0 Inde$ed So ted table 0 Inde$ed

1ashed table

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Standa d Table

♦ 1a!e an inte nal linea inde$

♦ Access uses a linea sea ch

♦ Access eithe by #ey o inde$

♦ Al.ays non-unique

♦ Response time o #ey access is p opo tional to

numbe o ent ies in table

♦ This can flled quic#ly2 no system chec#s onuniqueness o ent ies

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So ted Table

♦ Al.ays sa!ed so ted by #ey

♦ 1a!e inte nal linea inde$

♦ Access eithe by #ey o inde$

♦ Table can be unique o non-unique

♦ Response time o #ey access is lo%a ithmically

p opo tional to the no/ o ent ies since bina y sea ch

is used

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1ashed Table

♦ No inte nal linea inde$

♦ Access only usin% #ey

♦ Response time o access is independent o no/ o

table ent ies since system accesses the table usin%hash al%o ithm

♦ Table #ey must be unique

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Accessin% Inte nal Tables

3ou must access inte nal table line by line) usin% a .o # a ea as inte ace o t ans e in% data to "

om table


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Types o 4o # A ea

♦ 1eade line

♦ E$plicitly defned

Use only Work area,Do not use header line .

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5 eatin% Inte nal Table

Data/types like/type of [with header line] [initial size ].

Data/types : be in of o!!urs "#,


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Ran%es Tables

3ou can use the ollo.in% !a iants o the T3&ESand DATA statements to c eate inte nal tables o thesame type as selection tables/

T3&ES6DATA 7 an%e tab8 T3&E RAN9E :' 7type8/o T3&ES6DATA 7 an%e tab8 LI*E RAN9E :' 7ob;8/

This defnes inte nal standa d tables .hose linetype is a st uctu e as ollo.s(

♦ SI9N+. LI*E 7ob;8♦ 1I91 T3&E 7type8 b>. LI*E 7ob;8

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:pe ations :n Inte nal Table

♦ 'illin% inte nal tables

♦ So tin% inte nal tables

♦ Ret ie!in% lines om inte nal tables

♦ 5han%in% an inte nal table

♦ 5ont ol Le!el & ocessin%

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'illin% Inte nal Tables

♦ Appendin% lines usin% A&&END statement

♦ sin% INSERT statement

♦ sin% ?:@E statement

♦ Readin% om database !ia SELE5T command

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sin% A&&END Statement

Synta$This statement mo!e the contents o heade

line o .o # a ea as the last line o the specifed

inte nal table/&''()D to

*his state+ent works only with inde ed table as -ast line is !al!ulated internally usin the

internal inde

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sin% INSERT Statement

$) ( * into *&0-(

$) ( * into itab [$)D(1 ]

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'illin%/// sin% ?:@E Statement

5opyin% inte nal tables To copy enti e contents o one inte nal table to

othe s use mo!e statement/

234(


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'illin%/// sin% ?:@E Statement

MOVE-CORRESPONDING TO

This statement mo!es the contents o

the components o st uctu e 7st uct


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sin% Desc ibe Statement

DES5RIBE TABLE 7itab8 LINES 7l8 :55 RS

7n8

*IND 7#8T 0 Standa d Table

S 0 So ted Table

1 0 1ashed Table

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sin% SELE5T 5ommand

4e can fll inte nal table di ectly om database/

DATA itCma a li#e table o ma a/

SELE5T 'R:? ma a INT: TABLE itCma a

41ERE matn Fm-


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So tin% Inte nal Tables

4e can so t a standa d o hashed table in a p o% am/ synta$(

3 * [as!endin 6 des!endin ] [as te t] [stable] 07


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Ret ie!in% Lines

♦ Readin% the lines o inte nal table th ou%h heade

line o .o # a ea) o e-o %ani>ation o

manipulations o data/

♦ T.o .ays

sin% L::& 0 AT statement/

sin% READ statement

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sin% L::& AT

♦ 'o e!e y eco d o inte nal table the eco d is

mo!ed to the .o # a ea o heade line "

can be accessed di ectly om heade line/

L::& AT 7itab8 INT: 7.a8om 7n


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sin% READ Statement

♦ READ TABLE 7itab8 7#ey8 7 esult8

♦ READ TABLE 7itab8 INT: 7.a8 4IT1 *E3

7#ey8 7!al8 5:?&ARIN97


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5han%in% An Inte nal Table

4e can edit o chan%e the contents o aninte nal table a te it has been flled) usin%

?:DI'3 statement/

Synta$ (

23D$ 7 32 [* &) '3 *$); %% 6all fields] i n d e ,

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5han%in% An Inte nal Table

♦ sin% 5:LLE5T Statement

♦

sin% DELETE Statement

5:LLE5T INT:

DELETE INDEK ]

DELETE TABLE 'R:?

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5ont ol Le!el & ocessin%

It is allo.ed .ithin a L::& o!e an inte nal table/This means that you can di!ide sequences o

ent ies into % oups based on the contents o

ce tain felds/

AT 7le!el8

7statement bloc#8

ENDAT

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5ont ol Le!el & ocessin%

We !an find the total of nu+eri! fields, inside these !ontroltate+ent blo!ks usin U2 state+ent.

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Initiali>in% Inte nal Tables

♦ 5LEAR ♦ RE'RES1♦ 'REE

=-(& =-(& [ ]

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E$e cise

B, 5onside th ee inte nal tables .ith ollo.in% felds/Table < ?atn ) Desc iption/Table = ?atn ) &lant) uantity) :?) Amount/Table ?atn ) &lant) & ice/

Assume suitable feld types .hile defnin% the

inte nal tables/ &opulate suitable data +please lea!e Amount feld in Table = empty,/ 4 ite a p o% am to p ocess the contents o Table =/ 4 ite code to compute Amount feld and updateTable = as ollo.s/ se matn ) plant !alues omtable = and fnd the p ice om table / ?ultiply the

uantity .ith this p ice to update Amount feld inTable =/

4 ite code to display matn ) desc iption) plant)quantity) :?) & ice) Amount/

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THANK YOU

internal tables (1)

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