SELECT
   NULL OR TRUE, -- TRUE
   NULL OR FALSE, -- NULL
   NULL AND TRUE, -- NULL
   NULL AND FALSE -- FALSE

 CREATE INDEX idx1_gist1 ON gist1 USING spgist (c1) INCLUDE (c2) 

 CREATE INDEX idx1_data1 ON data1 USING brin (c1 numeric_bloom_ops (false_positive_rate = 0.05, n_distinct_per_range = 100)) 

 CREATE STATISTICS extstat1_data1 ON MOD(c1, 10), MOD(c2, 10) FROM data1 

 SELECT '{[1, 5), (10, 20]}'::int8multirange 

SELECT ('[1, "2", null]'::jsonb)[1] ;

SELECT ('{"age": 25}'::jsonb)['age'] ;

SELECT ('{"email":"pgsql-hackers@postgresql.org", "phone":"+3012345678"}'::jsonb) ['phone'] ;

INSERT INTO aws_ec2 (ami_id, ec2_instance_type_id)
SELECT ami.id, ait.id
FROM ec2_instance_type as ait, (
    SELECT id
    FROM   amis
    WHERE  image_name LIKE 'amzn-ami-hvm-%'ORDER BY creation_date DESC
    LIMIT 1
) as ami
WHERE  ait.instance_name = 't2.micro';

select:
  items:
    - foo
    - bar
  where:
    - eq:
      - foo
      - bar

null value in column "column1" of relation "table1" violates not-null constraint 

-- pg 13
null value in column "column1" of relation "table1" violates not-null constraint


-- pg 12
null value in column "column1" violates not-null constraint

SELECT count(*) FROM commits WHERE author_email = 'user@email.com'