Non-concurrent index creation locks the table for writes during the entire build.
CREATE INDEX without CONCURRENTLY acquires an exclusive lock, blocking all INSERTs, UPDATEs, and DELETEs on the table until the index is built.
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A regular CREATE INDEX acquires a SHARE lock on the table, blocking all write operations. On large tables this can take minutes or hours, causing application downtime.
Squawk catches this automatically:
squawk path/to/migration.sql
# Outputs: require-concurrent-index-creation-- Bad: locks the table
CREATE INDEX idx_users_email ON users (email);
-- Good: non-blocking
CREATE INDEX CONCURRENTLY idx_users_email ON users (email);Note: CREATE INDEX CONCURRENTLY cannot run inside a transaction block.
require-concurrent-index-creationsquawk --config .squawk.toml migrations/*.sql