Natural 2006 Practice Exam - Database Concepts

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2. What is used as an inverted list to get records from a file? Note that the inverted list stores these; they are also known as keys.

A descriptor is used as an inverted list to get records from a file. In this context, the descriptor serves as a key that helps retrieve specific records from the file. The inverted list, which is essentially a collection of these descriptors or keys, allows for efficient searching and retrieval of records based on specific criteria.

Explanation

A descriptor is used as an inverted list to get records from a file. In this context, the descriptor serves as a key that helps retrieve specific records from the file. The inverted list, which is essentially a collection of these descriptors or keys, allows for efficient searching and retrieval of records based on specific criteria.

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3. What describes the datatypes, lengths, and attributes of a file for a database (acronym)

The acronym "fdt" stands for File Definition Table, which describes the datatypes, lengths, and attributes of a file for a database. The File Definition Table is used to define the structure and characteristics of a file, including the types of data it can store, the length of each field, and any additional attributes or constraints that apply to the file. This information is crucial for organizing and managing data within a database system.

Explanation

The acronym "fdt" stands for File Definition Table, which describes the datatypes, lengths, and attributes of a file for a database. The File Definition Table is used to define the structure and characteristics of a file, including the types of data it can store, the length of each field, and any additional attributes or constraints that apply to the file. This information is crucial for organizing and managing data within a database system.

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4. What should you place in an error handling block for a program that edits an important database?

Backout transaction

End transaction

Terminate

Stop

Retry

If this application fails it should abort the transaction by doing backout transaction. This undos whatever modifications were done since the last end transaction.

terminate stops the current program. stop exits the natural environment. retry goes back to the code that caused the error.

Explanation

If this application fails it should abort the transaction by doing backout transaction. This undos whatever modifications were done since the last end transaction.

terminate stops the current program. stop exits the natural environment. retry goes back to the code that caused the error.

5. You have to update only a few records in the database, but you have to read a lot of records. Which method would reduce the number of records held?

DEFINE DATA LOCAL 1 WORK-VIEW VIEW OF WORK
2 ID-NO
2 NAME
2 DEPT
2 LOCATION
END-DEFINE

RD. READ WORK-VIEW BY ID-NO

IF DEPT = "HR" OR DEPT = "ACCOUNTING"

* YOUR CODE HERE

LOCATION := "CA"

UPDATE
END TRANSACTION

END-IF

END-READ

What's above is fine

Use the store record in work-view command first

Get work-view *isn (rd.)

Get work-view *isn

The store command is for adding new records. The problem with the above code is that it will lock every record read. Whenever a update command shows up, the record retrieved before it will be held. The get command is redundant since we are doing another adabas access. However, only the records retrieved with get will be locked. (rd.) refers to the label by the read command. This is so Natural knows where the ISN (internal sequence number) comes from.

Explanation

The store command is for adding new records. The problem with the above code is that it will lock every record read. Whenever a update command shows up, the record retrieved before it will be held. The get command is redundant since we are doing another adabas access. However, only the records retrieved with get will be locked. (rd.) refers to the label by the read command. This is so Natural knows where the ISN (internal sequence number) comes from.

6. Which of the following below is the default form of compression in Adabas?

No blank compression (NB)

Null suppression (NU)

Not Null (NN)

Fixed fields

Trailing blanks are removed for strings and leading zeros are removed and data is packed for numbers

NB does means that fields are stored without stripping blanks. NU means that the database only stores one byte for null values. NN requires that the field has a value.

Here is some info on field compression types:
http://documentation.softwareag.com/adabas/ada614unw/admin/fdtrec.htm#fisanchor0

Explanation

NB does means that fields are stored without stripping blanks. NU means that the database only stores one byte for null values. NN requires that the field has a value.

Here is some info on field compression types:
http://documentation.softwareag.com/adabas/ada614unw/admin/fdtrec.htm#fisanchor0

7. Mark which Natural commands can be used to retrieve records for the update command

Get

Read

Find

Histogram

The Natural 6.2.3 help only lists get, read, and find as commands to get records for update. Histogram only retrieves values from the inverted list.

Explanation

The Natural 6.2.3 help only lists get, read, and find as commands to get records for update. Histogram only retrieves values from the inverted list.

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8. What letter denotes a floating point datatype in adabas

A

G

B

P

U

A is alphanumeric, G is floating pt, B is binary, P is packed, U is Unpacked, and W is unicode

Explanation

A is alphanumeric, G is floating pt, B is binary, P is packed, U is Unpacked, and W is unicode

9. What type of database protocol holds off on locking until the record is modified

Pessimistic

Optimistic

Record holding

Transaction processing

Pessimistic locks the record as soon as it's accessed. Record holding is the act of locking a piece of the database, so it cannot be accessed or changed by other users.

Explanation

Pessimistic locks the record as soon as it's accessed. Record holding is the act of locking a piece of the database, so it cannot be accessed or changed by other users.

10. DEFINE DATA LOCAL 1 WORK-VIEW VIEW OF WORK 2 ID-NO (N6) 2 NAME (A20) END-DEFINE ID := 1 NAME := "JOHN DOE" * What is the command to add this to the database?

The command "STORE RECORD IN WORK-VIEW" is used to add the data, with the ID value of 1 and the NAME value of "JOHN DOE", to the WORK-VIEW database.

Explanation

The command "STORE RECORD IN WORK-VIEW" is used to add the data, with the ID value of 1 and the NAME value of "JOHN DOE", to the WORK-VIEW database.

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