runningStatementWhileHoldingAccessExclusive

Diagnostic Category: lint/safety/runningStatementWhileHoldingAccessExclusive

Since: vnext

Sources: - Inspired from: eugene/E4

Description

Running additional statements while holding an ACCESS EXCLUSIVE lock blocks all table access.

When a transaction acquires an ACCESS EXCLUSIVE lock (e.g., via ALTER TABLE), it blocks all other operations on that table, including reads. Running additional statements in the same transaction extends the duration the lock is held, potentially blocking all database access to that table.

This is particularly problematic because:

• The lock blocks all SELECT, INSERT, UPDATE, DELETE operations
• The lock is held for the entire duration of all subsequent statements
• Even simple queries like SELECT COUNT(*) can significantly extend lock time

To minimize blocking, run the ALTER TABLE in its own transaction and execute other operations in separate transactions.

Examples

Invalid

ALTER TABLE authors ADD COLUMN email TEXT;
SELECT COUNT(*) FROM authors;

Valid

-- Run ALTER TABLE alone, other queries in separate transactions
ALTER TABLE authors ADD COLUMN email TEXT;

How to configure

{
  "linter": {
    "rules": {
      "safety": {
        "runningStatementWhileHoldingAccessExclusive": "error"
      }
    }
  }
}