Q:

Filter out records that exist in another table

Table A has 
100 records with Column1 in focus
Table B has 
10 records with Column1 in focus
So I have to always filter out the records in Table A based on the column1 in Table b
Table_B = foreach B generate flatten(TOTUPLE(SEN_NBR));

result = FILTER TABLE_A BY SEN_NBR NOT IN (Table_B);

any help would be great! 

A:

Use a LEFT OUTER JOIN and filter out the nulls. That will give only the records from Table A which are not in Table B
A = JOIN Table_A BY SEN_NBR LEFT OUTER,Table_B by SEN_NBR;
B = FILTER A by Table_B.SEN_NBR is null;

NOTE:I've answered a similar question with an example here

