Niko Neugebauer looks at some techniques for copying data into a table in an Azure Synapse Analytics SQL Pool:
First of all, let us list some of them (and I am not even attempting on providing all of them, of course):
– INSERT INTO … SELECT FROM … (the most well known one)
– SELECT INTO … FROM … (the most well-known to perform well, since it will create a HEAP while copying most of the properties from the original table(s))
– CREATE TABLE … AS SELECT … (the old way, which must be like 10 years old on PDW/APS & Azure SQL DW, but that has never gotten into a Box Product or Azure SQL Database)
– Polybase (that will use the External Tables & externally allocated data to transfer into Azure SQL DW)
– BCP (good old tested friend that will give you a pain in the neck until you dominate it)
– OPENROWSET / BULK INSERT (some very good and very old friends with complicated histories (who remembers all the code pages?, settings and uncertain future mostly because of their original restrictions, I guess)
– COPY INTO … (the brand new command that will allow you under very neat privileges to copy data from the external storage accounts, much like BULK INSERT)
In this blog post I will simply focus on those features that have not been ported (hopefully just yet): CTAS & COPY INTO.
Read on to see how these two work. Also, I too have wanted CTAS in on-premises SQL Server for years.