Eugene Documentation

✅ Eugene trace report

Script name: examples/W14/bad/1.sql

✅ Statement number 1 for 10ms

-- 1.sql
create table authors(
    name text
)

Locks at start

No locks held at the start of this statement.

New locks taken

No new locks taken by this statement.

✅ Eugene trace report

Script name: examples/W14/bad/2.sql

✅ Statement number 1 for 10ms

-- 2.sql
create unique index concurrently
    authors_name_key on authors(name)

Locks at start

No locks held at the start of this statement.

New locks taken

No new locks taken by this statement.

❌ Eugene trace report

Script name: examples/W14/bad/3.sql

✅ Statement number 1 for 10ms

-- 3.sql
set local lock_timeout = '2s'

Locks at start

No locks held at the start of this statement.

New locks taken

No new locks taken by this statement.

❌ Statement number 2 for 10ms

alter table authors
    add constraint authors_name_pkey
        primary key using index authors_name_key

Locks at start

No locks held at the start of this statement.

New locks taken

Triggered rules

E1: Validating table with a new constraint

A new constraint authors_name_pkey of type PRIMARY KEY was added to the table public.authors as VALID. Constraints that are NOT VALID can be made VALID by ALTER TABLE public.authors VALIDATE CONSTRAINT authors_name_pkey which takes a lesser lock.

E2: Validating table with a new NOT NULL column

The column name in the table public.authors was changed to NOT NULL. If there is a CHECK (name IS NOT NULL) constraint on public.authors, this is safe. Splitting this kind of change into 3 steps can make it safe:

1. Add a CHECK (name IS NOT NULL) NOT VALID; constraint on public.authors.
2. Validate the constraint in a later transaction, with ALTER TABLE public.authors VALIDATE CONSTRAINT ....
3. Make the column NOT NULL