Why is Synthetic Key forming when loading Multiple CSVs with exact same fields?

[Prasun7]

Table1:
LOAD * INLINE [
Name,Email1
Person2,sdfdf
Person3,gff
];
LEFT KEEP(Table1)
BaseTable:
Load
Name,Marks
From [lib://Path/A*.csv]
(txt, utf8,embedded labels, delimiter is ',', msq);
Exit script;

//The data source path has 3 CSVs A1.csv, A2.csv & A3.csv. Why are these CSVs forming synthetic key instead of Concatenating?

[rubenmarin]

Hi, it's because it's creating a differnt table for each file, try with exists instead of left keep:

Table1:
LOAD * INLINE [
Name,Email1
Person2,sdfdf
Person3,gff
];

BaseTable:
Load
Name,Marks
From [lib://Path/A*.csv]
(txt, utf8,embedded labels, delimiter is ',', msq) Where Exists(Name);
Exit script;

[Prasun7]

Yes, but why is it creating different tables for each file? According to the Qlik documentation, it should auto Concatenate the tables with same name and number of fields.

[marcus_sommer · Accepted solution]

The auto-concatenation feature worked only for "normal" load-statements like expected. The combination of a load with additionally statements like your left keep changed the behaviour because it's a join-statement (that the join-table remained afterwards isn't important for the technically implementation else it's a special kind of on-top-feature).

Essentially is the order of execution of the various and multiple parts. In This case your wildcard-loop over all A*Files isn't applied at first and creating a concatenated table else the first file is loaded and joined against the target-table and after that the second file is taken and joined and so on.

I don't know how all this is exactly technically implemented but within the most cases you will need to pre-load your (n sub-) tables/files into an existing single-table if you want to use them for join- and mapping-operations. It might look like more efforts as needed but I deduce from this behaviour that Qlik doesn't use temporary table buffer-layer else  the write/evaluate the data immediately against the system-tables.

- Marcus