*sigh* Yup, I know the feeling.

A client wants a SQL 2016 upgrade (from 2008 R2). I gave them a rough timeline, including analysing the environment (they don't fully...

If you're using ad-hoc queries, they should be parameterised, not have embedded literals. That's just good practice (and prevents SQL injection). At which point it's parameterised query vs parameterised query.

They're completely different.

Procedures are objects that you call and execute. They have cached plans.
Views are used as part of other statements. The other statements have plans, but...

Sure. Use the sys.dm_db_stats_properties DMV to decide which stats to update.

Personally I wouldn't link packages direct to hotels. Packages link to day details, which links to Hotel.

There's way too many tables there
Why are package and package duration...

And if it's not homework, consider getting an external consultant/contractor in who's familiar with DB design. Designing a full DB from sparse requirements is a bit beyond a forum's free...

An update statement can't go into an infinite loop, not by itself. To get an infinite loop, you need a loop, ie a WHILE or a procedure that calls itself

First things first, repair with allow_data_loss is not the first thing you should try. It's a last resort. It loses data. How much, hard to tell.
Restoring from a...