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Random update. Please use speaker notes for additional information!. Update. Random Update.

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Random update

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Random update

Random update

Please use speaker notes for additional information!


Random update

Update

Random Update

  • EDIT: The transactions that will be used in the update must be as error free as possible to prevent corrupting the master file. To assure the integrity of the data, the transactions can be processed in an edit program and only valid transactions should be allowed to update the master file. The output of the edit file includes the valid (good) transaction file which will be processed in the next step. Frequently transaction come in via a screen and the analyst decides that the editing will be incorporated in the update program to provide interactivity.

  • UPDATE:The update program uses the valid transaction file to update the master file itself. No new master file is created, the changes are made to the existing master file. Note that random updating is transaction driven. This means that you read the transaction file and find the master that needs to be updated. When you have processed all of the transactions, the processing is done. Reports become extremely important to provide a paper trail of records processed and also a trail of records that contained errors and were not processed. In a maintenance update there can be add, change or delete transactions so records can be added to the existing master, changed on the existing master, or deleted from the existing master. The method of physically handling deletes varies depending on technology being used.. The update program completes the updating maintenance cycle. Note that back up does not happen automatically in a random update. Copies of the master file and the transaction file need to be made. Frequently the master is backed up directly after the update. It absolutely has to be backed up before the next update.


Random update

Systems flowchart

Valid

Trans

Update

Program

Data

Edit

Program

Errors

Errors can be put on disk, printed, interactively corrected or any combination of solutions.

Master

File

Trail

Note: Errors can be written to disk, printed, interactively corrected or any combination of solutions. An optional paper trail can also be produced on disk, paper or another medium.


Random update

Random Update

Screen

Transactions

OR

Transactions

Master

Random Update

Program

If transactions are coming in as a group from a disk file, they should be edited. If the transactions are coming from a screen, interactive editing should take place in the Random Update Program. The user will frequently try to interactively handle errors on the screen.

Errors

Trail


Random update

Random Update Logic


Random update

readTrans

process

start

Read a

transaction

housekeeping

readTrans

Y

end-readTrans

process

not EOF

loop

N

wrapup

end-process

readMstr

stop

read master

housekeeping

wrapup

Y

N

successful

open files

close files

success

not success

end-housekeeping

end-wrapup

end-readMstr


Random update

loop

establish key

read mstr

Y

N

success

N

change

trans

Y

Y

N

add

trans

N

delete

trans

change

routine

Y

Y

add

routine

N

change

trans

add

error

routine

delete

routine

rewrite

master

write

master

delete

error

routine

change

error

routine

delete

master

readTran

end -loop


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

222...

234…

333...

345…

444...

456…

512…

121 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. If a match is found,

changes are made to the record on the master and the record is put back on the master with a REWRITE.

A trail of the change is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

124...

222...

234…

333...

345…

444...

456…

512…

121 (trail)

124 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since no match is found and this is an add,

the new record is written on the Master using a WRITE.

A trail of the add is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

124...

222...

234…

333...

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since a match is found and this is a change,

the change is made and the changed Master replaces the original record on the master using the REWRITE.

A trail of the change is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

124...

222...

234…

333...

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

222 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since a match is found and this is a change,

the change is made and the changed Master replaces the original record on the master using the REWRITE.

A trail of the change is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

124...

222...

234…

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

222 (trail)

333 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since a match is found and this is an delete,

the delete is made by removing the record from the Master using the DELETE verb.

A trail of the delete is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

999...

MASTER (after)

121...

123…

124...

222...

234…

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

222 (trail)

333 (trail)

350 (error)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since no match is found and this is a change,

no change is made to the master.

A report of the change error is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

MASTER (after)

121...

123…

124...

222...

234…

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

222 (trail)

333 (trail)

350 (error)

444 (error)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since a match is found and this is a add,

no change is made to the master.

A report of the add error is also made.


Random update

Random Update

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

121…C

124…A

222…C

222…C

333…D

350… C

444… A

450… D

MASTER (after)

121...

123…

124...

222...

234…

345…

444...

456…

512…

121 (trail)

124 (trail)

222 (trail)

222 (trail)

333 (trail)

350 (error)

444 (error)

450 (error)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since no match is found and this is a delete,

no change is made to the master.

A report of the delete error is also made.


Random update

Random Update with unsorted transactions

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

350…C

222…C

124…A

450…D

333…D

121… C

444… A

222… C

999...

MASTER (after)

121...

123…

222...

234…

333...

345…

444...

456…

512…

350 (error)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since no match is found and this is a change,

no change is made to the master.

A report of the change error is also made.


Random update

Random Update with unsorted transations

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

350…C

222…C

124…A

450…D

333…D

121… C

444… A

222… C

999...

MASTER (after)

121...

123…

124...

222...

234…

333...

345…

444...

456…

512…

350 (error)

222 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since a match is found and this is a change,

the change is made and the changed Master replaces the original record on the master using the REWRITE.

A trail of the change is also made.


Random update

Random Update with unsorted transactions

ERROR /TRAIL REPORT

MASTER (before)

121...

123…

222...

234…

333...

345…

444...

456…

512…

TRANSACTIONS

350…C

222…C

124…A

450…D

333…D

121… C

444… A

222… C

999...

MASTER (after)

121...

123…

124...

222...

234…

333...

345…

444...

456…

512…

350 (error)

222 (trail)

124 (trail)

The transaction is read

and then there is an attempt made to find the matching record identification number on the Master. Since no match is found and this is an add,

the new record is written on the Master using a WRITE.

A trail of the add is also made.


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