The sample prefix to a LOAD or SELECT statement is used for loading a random sample of records from the data source.
Sample p ( loadstatement | selectstatement )
An arbitrary expression which valuates to a number larger than 0 and lower or equal to 1. The number indicates the probability for a given record to be read.
All records will be read but only some of them will be loaded into Qlik Sense.
Sample 0.15 SQL SELECT * from Longtable;
Sample(0.15) LOAD * from Longtab.csv;