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Table Variable Deferred Compilation

Deepthi Goguri takes us through a fairly new feature in SQL Server:

With SQL Server 2017 and below versions, SQL Server always estimates one row for table variable as the table variable data gets inserted during the run time, so optimizer doesn’t know how many values it can expect coming out of the table variable. Due to this bad estimation, performance of the queries is effected.

Click through to see how this has changed in SQL Server 2019.