Check value if exists in column

EXISTS should normally return as soon as the subquery finds one row that satisfies its WHERE clause. So I think your query is as fast as you can make it. I was a little surprised that LIMIT 1 seems to always speed up the query very slightly. I didn’t expect that. You can see the … Read more

docker-entrypoint-initdb.d bad interpreter: Permission denied

I ended up running into this same issue. For anyone who faces this, you need to give execution permission to your script file, since Docker copies over permissions: chmod +x your/ In my case the issue msg was: /opt/bitnami/scripts/ /docker-entrypoint-initdb.d/ /bin/bash: bad interpreter: Permission denied Then I gave execution permission to and it worked … Read more

LISTEN/NOTIFY using pg_notify(text, text) in PostgreSQL

I have discussed this on the PostgreSQL mailing list ( and was informed on the reasoning for the behavior. Their answer is that “ have to double quote relnames (listen “Test”). if you want the server not to case fold them. pg_notify takes a string, not a relname, which uses different rules.” (Thanks Merlin and … Read more

Oracle equivalent of Postgres’ DISTINCT ON?

The same effect can be replicated in Oracle either by using the first_value() function or by using one of the rank() or row_number() functions. Both variants also work in Postgres. first_value() select distinct col1, first_value(col2) over (partition by col1 order by col2 asc) from tmp first_value gives the first value for the partition, but repeats … Read more

How do you do UUID in Golangs Gorm?

For postgresql, here is what I did: go get Use uuid.UUID (from “”), as type, e.g ID uuid.UUID `gorm:”type:uuid;default:uuid_generate_v4()”` Add uuid-ossp extension for postgres database, e.g CREATE EXTENSION IF NOT EXISTS “uuid-ossp”; Then, when you call DB’s Create() method, the uuid is generated automatically. Update: pg14+ gen_random_uuid() (as mentioned in Doron Segal‘s comment) pg … Read more