Temp tables, cursors, sorts and row versioning all use TempDB. Here is the script I use to find who is consuming my TempDB right now.
SQL SERVER – Story of Temporary Objects
Temp tables, table variables and more: the story of Temporary Objects in SQL Server, why you would use them and how they can help performance and scalability.
SQL SERVER – Is tempDB behaving like a Normal DB?
TempDB is a special shared database, but in many ways it behaves like a normal DB with a twist. I share how I explained it to DBAs during my tuning work.
Memory-Optimized Table Variables
Memory-optimized table variables can avoid tempdb work, but they need a filegroup, indexed table type, memory budget, and workload tests.
Fixing Collation Conflicts Between tempdb and Your Database
Fix tempdb collation conflicts with DATABASE_DEFAULT, compare a join-level COLLATE, and inspect contained-database behavior.
Temp Table Scope in Nested Procedures and Dynamic SQL
Explain temp table scope across nested procedures and dynamic SQL, reproduce missing and duplicate-name errors, and pass rows safely.
Cursor Options That Matter: LOCAL, FAST_FORWARD and STATIC
Test SQL Server cursor options, including LOCAL FAST_FORWARD and STATIC, on one loop while measuring time and tempdb cost.