Correlated vs uncorrelated subqueries

A subquery is a query that is used in another query. Another example of subqueries can be as simple as the example below. A correlated subquery is a subquery where a reference is made to the outer query. An uncorrelated subquery is a subquery where no reference is made to the outer query. For the…

Tasks in Snowflake

Tasks are an excellent scheduling tool in Snowflake. You can use tasks for a lot of different purposes. Below are some examples: The scheduling can be done using CRON (for example, run a task every hour, minimum schedule is one minute) or using a trigger. You could trigger a task to run after another task…

Streams in Snowflake

A stream is a great way to track changes to a source table in #Snowflake. These tracked changes can then be used to create an incremental load for example. There are 3 types of streams: – Standard: tracks all data manipulation changes to an object. – Append-only: tracks only inserts. – Insert-only: tracks only inserts…

Lambda functions in Python: what are they?

Ever encounter a python script with a “lambda” lurking somewhere in the blocks of code? Didn’t know what to make of it? I’ve got you covered… Put simply, a lambda function is a small anonymous function. It is mostly used for cases that do not require a separate function for whatever reason. Syntax is relatively…

Bestanden in twee verschillende folders met elkaar vergelijken met behulp van Python en de niet-overlappende bestanden in een nieuwe folder opslaan

Een week geleden schetste ik een voorbeeld van twee folders waarvan de inhoud enige overlap heeft. De bestanden die in folderA voorkomen, maar NIET in folderB, werden in dat voorbeeld geïdentificeerd. Maar dit kan beter …! In het Python script wat via de onderstaande link te vinden is, wordt wederom gekeken naar de niet-overlappende bestanden.…