Structure of Symbol Tables using AutoNumber on Key fields

[QlikWilliam]

Hello,

Am I correct in understanding that if I use AutoNumber on a key field, for instance

AutoNumber(ProductID&CustomerID)

that the symbol table for the Key Field "ProductID&CustomerID" would look like this?

Pointer   Value

1

2

that is, that the Value is empty because a look-up is not needed? Or would the symbol table look like this?

Pointer   Value

1             1

2             2

Also is there a way to view the symbol tables? Thank you. 

[Chanty4u]

Yes the Value becomes a simple integer, and the original concatenated string is no longer stored in the field.

Or  try this 

AutoNumberHash128(ProductID, CustomerID)

[rwunderlich · Accepted solution]

It would look like neither. When a field contains only sequential integers, the index value in the table row is used as the value. So there is no symbol table. I think you might be saying this in your first example.

-Rob

[QlikWilliam]

Thanks for your replies!

I did not realize there would be no symbol table at all. But it makes sense.

Should we always use AutoNumber on key fields? Or is there a drawback?

[rwunderlich]

I recommend always using the AutoNumber on key fields.

I would also recommend using the AutoNumber statement rather than the AutoNumber() function. Just put the statement at the end of your script. Much easier and much faster.

-Rob
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