TAW_11 Chapter 3, Internal tables

Question 1

Its okay to resort sorted tables?

Answer 1

NEVER!!!

Question 2

You can append a sorted table?

Answer 2

Only if the appended line will be in the correct order.

Question 3

All reads of a sorted table are binary by default?

Answer 3

Correct

Question 4

Can a hash table be sorted?

Answer 4

Yes, and this is appropriate if the hash table is to be used in a loop/endloop

Question 5

What is the safest way to add a row to a sorted table?

Answer 5

insert with key

Question 6

three operations might cause issues with a sort table violation.

Answer 6

INSERT, APPEND, MODIFY by index

It is best to INSERT using key and Modify using key. Best to avoid APPEND altogether

Question 7

What is implicit specification with table operations?

Answer 7

using FROM where <> is a populated object with the a line of the table lne

Question 8

What are the 4 ways of reading a table

Answer 8

By index (index)
by table key (with table key)
by any key (with key)
by implicit key (from)

Question 9

What two keywords are mutually exclusive when writing table statements?

Answer 9

INDEX and TABLE will never occur together

Question 10

By default does the insert use the table key?

Answer 10

Yes

Question 11

Hashed tables cannot use index access?

Answer 11

This is true

Question 12

Can I use MODIFY with table key to change key fields?

Answer 12

No, MODIFY by index will allow key fields to be changed. Do not use this with sorted tables and cannot be used with hashed tables

Question 13

What table access commands can use implicit keys?

Answer 13

DELETE, MODIFY,INSERT, READ

Question 14

MODIFY by key and INSERT by KEY can only use what type of key

Answer 14

Implicit

Question 15

When performing INSERT, MODIFY, DELETE with in a table loop, what part of the syntax can be left out?

Answer 15

INDEX. The index will default to sy-tabix so
INSERT INTO
implies INSERT into INDEX

Question 16

Can the abbreviated syntax (no index specified) be used outside of a loop?

Answer 16

No, It will not cause a syntax error but will cause a runtime error

Question 17

Can MODIFY be used with a WHERE clause?

Answer 17

Yes, but you must specify TRANSPORTING

Also, WHERE can only be used with MODIFY, not MODIFY TABLE

Question 18

Can DELETE be used with a where clause?

Answer 18

Yes, but only with DELETE, not with DELETE TABLE

Question 19

Cn WHERE be used with HASHED tables?

Answer 19

Yes, within a loop only

Question 20

What happens when you attempt to add a line to a sorted table with a unique key and the record already exists?

Answer 20

Just a sy-subrc 4. no dump

Question 21

Can MOVE-CORRESPONDING be used with internl tables?

Answer 21

Yes, move-corresponding to works fine as long as no unique key violations exist in as a result of the move

Question 22

What if I want to move entries from to but I want to keep the records already in ?

Answer 22

Use KEEPING TARGET LINES addition

Question 23

DELETE ADJACENT DUPLICATES can be used with a HASED table?

Answer 23

It appears so but I need to check. It could only be on secondary key comparisons correct?

Question 24

Which table types can be used with the collect statement?

Answer 24

All three, but SAP says that COLLECT is best suited for HASHED tables

Question 25

What are the three types of secondary tables that can be defined for an internal table?

Answer 25

Unique standard 
WITH UNIQUE KEY 
COMPONENTS  
Non-unique sorted 
WITH NON-UNIQUE KEY 
COMPONENTS  
Unique hashed
WITH UNIQUE HASHED KEY 
COMPONENTS  
All table types can have these keys

Question 26

What is the maximum number of secondary keys on an internal table

Answer 26

15

Question 27

How is a secondary accessed

Answer 27

READ/MODIFY/DELETE   INDEX # USING KEY.
or 
READ TABLE  WITH KEY  COMPONENTS...
or
READ/MODIFY/DELETE TABLE  from  USING KEY

Question 28

Secondary keys are always immediately updated

Answer 28

No, they are lazy updates that are only updated when first used or used after an update
the exception is unique keys which are updated immediately to check for uniqueness violation

Question 29

Replace the following with a new table expression

READ TABLE INDEX idx INTO

Answer 29

= [ idx ]

Question 30

Replace the following with a new table expression

READ TABLE INDEX idx USING INTO

Answer 30

= [ KEY INDEX idx ]

Question 31

READ TABLE WITH KEY =
=
into

Answer 31

= [ = = ]

Question 32

READ TABLE WITH TABLE KEY
COMPONENTS
=
=
into

Answer 32

= [ KEY  
                         COMPONENTS
                                = 
                                =  ]
or
 = [ KEY  
                                = 
                                =  ]

Question 33

How would you use the VALUE statement to add info to an internal table with columns col1, col2, col3?

Answer 33

= VALUE #(
( col1 =
col2 =
col3 = )
( col1 = ) )

Question 34

What does the keyword BASE do?

Answer 34

Existing content of the table is kept.
e.g.
= VALUE #( BASE =
< col1> = ) )

Question 35

What would the following statement do?
= VALUE #( FOR IN
WHERE ( = )
( = )

Answer 35

A new entry in table will be created for every row in where col1 = val1. The new line in tab1 will have a value of val2 in col2

Not we did not save current values in tab1 by using and BASE.
Also, the WHERE clause must be in parentheses

Question 36

What do LINE_EXISTS and LINE_INDEX do

Answer 36

LINE_EXISTS returns the Boolean value (predicate)

LINE_INDEX returns the index number (descriptive)

Question 37

do all data references need to be dereferenced?

Answer 37

No, if the referenced object is a structure the components can be addressed directly using the -> syntax. e.g. dataref->col1

Question 38

How can a generic reference (type data for example)

Answer 38

The reference must be assigned to a field symbol in order to be able to access the content

Question 39

How is a data object assigned to a data reference?

Answer 39

GET REFERENCE OF fld INTO ref
or
ref = REF #( fld )

Question 40

How can I tell if a reference has been bound?

Answer 40

ref IS BOUND
or
ref IS NOT BOUND

Question 41

Technically what is a field symbol?

Answer 41

A dereferenced pointer

Question 42

How is a field symbol assigned and unassigned

Answer 42

ASSIGN fld to

UNASSIGN

Question 43

Unlike a standard table, when accessing a sorted or hashed table and assigning to a field symbol, what can not be done?

Answer 43

The contents of the field symbol cannot be changed

Question 44

What happens if I reassign or unassign a field symbol used as the target of a lopp?

Answer 44

runtime error

Question 45

Can the SUM statement be used if the loop is assigning a field symbol?

Answer 45

no

Question 46

Can field symbols be used with INSERT, COLLECT, MODIFY?

Answer 46

Yep