debian-mirror-gitlab/db/migrate/20201019161924_add_partitioned_table_view.rb
2021-01-29 00:20:46 +05:30

44 lines
1.3 KiB
Ruby

# frozen_string_literal: true
class AddPartitionedTableView < ActiveRecord::Migration[6.0]
DOWNTIME = false
def up
execute(<<~SQL)
CREATE OR REPLACE VIEW postgres_partitioned_tables AS
SELECT
pg_namespace.nspname::text || '.'::text || pg_class.relname::text AS identifier,
pg_class.oid AS oid,
pg_namespace.nspname AS schema,
pg_class.relname AS name,
CASE partitioned_tables.partstrat
WHEN 'l' THEN 'list'
WHEN 'r' THEN 'range'
WHEN 'h' THEN 'hash'
END as strategy,
array_agg(pg_attribute.attname) as key_columns
FROM (
SELECT
partrelid,
partstrat,
unnest(partattrs) as column_position
FROM pg_partitioned_table
) partitioned_tables
INNER JOIN pg_class
ON partitioned_tables.partrelid = pg_class.oid
INNER JOIN pg_namespace
ON pg_class.relnamespace = pg_namespace.oid
INNER JOIN pg_attribute
ON pg_attribute.attrelid = pg_class.oid
AND pg_attribute.attnum = partitioned_tables.column_position
WHERE pg_namespace.nspname = current_schema()
GROUP BY identifier, pg_class.oid, schema, name, strategy;
SQL
end
def down
execute(<<~SQL)
DROP VIEW IF EXISTS postgres_partitioned_tables
SQL
end
end