Articles related to Postgres from the team that helps B2C companies build and defend revenue with AI.
Here's a great way to make Rails apps running on Postgres more inspectable. Just put this in config/initializers/application_name.rb: ActiveRecord::Base.connection.class.set_callback(:checkout, :after) { raw_connection.exec "set application_name = 'MyRailsApp'" } Now when you inspect pg_stat_activity, you can tell which
pg_query is a really cool Ruby library that uses Postgres's query parser to give you programmatic access to SQL queries. One thing you can do with it is read a CREATE TABLE statement to map column names to column types: sql = <<-SQL CREATE TABLE example ( my_text
So you've got a table with a UUID primary key. How do you search for only 1/4, or 1/8, or 1/128 of it? BETWEEN '00000000-0000-0000-0000-000000000000' AND '3fffffff-ffff-ffff-ffff-ffffffffffff' BETWEEN '40000000-0000-0000-0000-000000000000' AND '7fffffff-ffff-ffff-ffff-ffffffffffff' BETWEEN '80000000-0000-0000-0000-000000000000' AND 'bfffffff-ffff-ffff-ffff-ffffffffffff' BETWEEN 'c0000000-0000-0000-0000-000000000000' AND 'ffffffff-ffff-ffff-ffff-ffffffffffff' And how do you generate those ranges? Here
UPDATED with fixes from @jeremyevans Going back and forth between ActiveRecord and Sequel can be very confusing... especially because the Sequel documentation assumes that you use "datasets" instead of raw sql. What ActiveRecord Sequel One value ActiveRecord::Base.connection.select_value(sql) DB[sql].get One row as
This is part of our series on PostgreSQL and things that are obvious once you see them. It's a 2017 update to our 2016 article How to merge JSON fields in Postgres Nice! Update We used to call this jsonb_collect, but then we realized it was very similar to
This post is part of our PostgreSQL series. SQL cursors are a great way to stream data out of a database without loading it all into memory. Reading using a cursor Sequel has use_cursor: BATCH_SIZE = 1000 DB[:widgets]. select(:id, :name, :power). use_cursor(rows_per_fetch: BATCH_