Interview Preparation
SQL Interview: Indexes, Transactions and ACID
The performance and concurrency half of a SQL interview: how indexes work, what they cost, ACID, isolation levels and deadlocks.
#Transactions
Units of work, commit, rollback and ACID.
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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
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.
SQL
ACID Properties Explained
Atomicity, consistency, isolation and durability - what each guarantee actually promises, how the database delivers it, and where each one can be weak...
SQL
BEGIN, COMMIT, ROLLBACK and Savepoints
Grouping statements into one unit of work that either fully applies or fully undoes. Learn transaction boundaries, savepoints, autocommit and what sil...
SQL
Stored Procedures and Parameters
Named procedural code stored in the database. Learn CREATE PROCEDURE, IN, OUT and INOUT parameters, control flow, and when a procedure is the right to...