Which lock types best describe typical row-level reads and writes?

Problem Statement

Explanation

Reads either take shared locks (blocking writers on those rows) or read MVCC versions without locking them. Writes need exclusive intent so concurrent writers do not conflict. Lock names and hierarchy vary by engine, but the concept of shared versus exclusive is common.

Code Solution

SolutionRead Only

UPDATE inventory SET qty=qty-1 WHERE sku='X'; -- exclusive row lock

Practice Sets

This question appears in the following practice sets:

Transactions, Concurrency & Isolation

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Which lock types best describe typical row-level reads and writes?

Problem Statement

Explanation

Code Solution

Practice Sets

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Master Interviews Anywhere, Anytime

Which lock types best describe typical row-level reads and writes?

Problem Statement

Explanation

Code Solution

Practice Sets

Related Questions

Which SQL statement retrieves all columns and rows from a table named employees?

Which clause filters rows before aggregation and affects which rows are grouped?

What is the default sort order when ORDER BY is used without ASC or DESC?

Which construct is commonly used to paginate results in SQL engines like Postgres and MySQL?

Which predicate correctly checks for missing values in standard SQL?

More from SQL & Databases

Master Interviews
Anywhere, Anytime