Interview Q&A / PostgreSQL
PostgreSQL interview questions
Indexes, EXPLAIN, transactions and isolation, JSONB and the Postgres specifics backend interviews probe.
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- How does PostgreSQL implement transaction isolation levels?
PostgreSQL offers Read Committed (the default), Repeatable Read and Serializable. Dirty reads never happen, even if you ask for Read Uncommitted. Read Committed takes a new snapshot per statement, Repeatable Read keeps one snapshot for the whole transaction, and Serializable adds checks that abort a transaction if the result could not have come from running transactions one at a time.
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