Connecting to a 4 tables in an Oracle Database

Question

Hi All,

I am new to Alteryx, I for the first time in my career I am working in a company that allows me to get into the DataMart.

I am excited because I know the richness of the data we have and so far I have been able to produce some valuable insights using only tableau and analyzing only the P&L Table.

I have download the trial and while joining 4 tables from the datamart for later create a filter to minimize the data retrieved it didnt work. It download more than 20gb while it should only be a report of 160k rows. For sure I am doing something wrong, can anyone advise what is the best flow to connect 4 tables in a database but create a filter first before to avoid downloading that much data. I made the connections in the query and not in the canvas.

Thanks,

Luis Maldonado

dataMack · Accepted Answer

If you are seeing that much data come back from what you know are relatively small tables, and you made the connections (joins) in the SQL itself as you say, then likely what you are seeing is the result of a Cartesian product.  There is probably an error in your join criteria that is causing the # of rows to multiply as each row gets joined to every other row.

If you're familiar with SQL, just take a second look at your Where clause and edit it to make sure you are including the appropriate key(s) for each table.

With Oracle, you could also use an In-Database connection and In-Database join tool to let Alteryx help guide you to ensure you are joining everything correctly.  With In-Database tools, Alteryx writes the SQL for you based on your configuration of those dark-blue tools.