What Is a Data Lock

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What Is a Data Lock

Q

What Is a Data Lock? - MySQL FAQs - Transaction Management: Commit or Rollback

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A

MySQL uses two types of data locks at two levels to provide you the transaction isolation level you need:

Share Lock at Row Level (S) - A data row is locked by a transaction for reading.
Exclusive Lock at Row Level (X) - A data row is locked by a transaction for updating and deleting.
Intention Share Lock at Table Level (IS): A data table is locked by a transaction for placing share locks at row level.
Intention Exclusive Lock at Table Level (IX): A data table is locked by a transaction for placing exclusive lock at row level.

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