Interview Q&A / PostgreSQL
PostgreSQL interview questions
Indexes, EXPLAIN, transactions and isolation, JSONB and the Postgres specifics backend interviews probe.
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- What is the difference between SERIAL and IDENTITY columns, and when would you use a UUID primary key?
SERIAL is an older PostgreSQL shorthand that creates a sequence and sets it as the column default. IDENTITY (GENERATED ALWAYS or BY DEFAULT AS IDENTITY) is the SQL-standard replacement and is preferred for new tables. Use a UUID when IDs must be generated outside the database, merged across systems, or must not be guessable.
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