SQL
Isolation Levels and Read Phenomena
The four isolation levels, the three anomalies they prevent, and what each database actually defaults to - with the session by session demonstrations.
Isolation and Locking
Isolation levels, read phenomena, locks, deadlocks and contention.
3 notes
Notes
SQL
Locks: Shared, Exclusive, Row and Table Level
How the database stops two transactions corrupting each other: lock modes, granularity, locking reads, and why an unindexed WHERE clause can lock a wh...
SQL
Deadlocks and Lock Contention
Why two transactions can wait for each other forever, how the database resolves it, and the design habits that prevent deadlocks and reduce contention...