All we need is an easy explanation of the problem, so here it is.
I need to get metadata about all MATERIALIZED VIEW columns, including their data type. I can do this with this query:
SELECT trim(leading '_' from pg_type.typname) as data_type, pg_namespace.nspname as schema_name, pg_namespace.nspname as udt_name, attnum AS ordinal_position, pg_attribute.attname as column_name, pg_class.relname as matview_name, '-------' AS spacer, * from pg_catalog.pg_attribute join pg_catalog.pg_class ON pg_class.oid = pg_attribute.attrelid join pg_catalog.pg_namespace ON pg_namespace.oid = pg_class.relnamespace join pg_catalog.pg_type ON pg_type.typelem = pg_attribute.atttypid where pg_class.relkind = 'm' AND not pg_attribute.attisdropped and cast(pg_type.typanalyze as text) = 'array_typanalyze' and pg_attribute.attnum > 0 order by pg_attribute.attnum
However it doesn’t list any array columns, due to them not existing in the
pg_catalog.pg_type table (which is the table I’m getting the data types from).
How can I also get metadata (including type) for array columns too?
I’m using postgres 13.3.
How to solve :
I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.
You can make your life easier using the
SELECT format_type(att.atttypid, att.atttypmod) as data_type, nsp.nspname as schema_name, att.attnum AS ordinal_position, att.attname as column_name, mv.relname as matview_name from pg_catalog.pg_attribute att join pg_catalog.pg_class mv ON mv.oid = att.attrelid join pg_catalog.pg_namespace nsp ON nsp.oid = mv.relnamespace where mv.relkind = 'm' AND not att.attisdropped and att.attnum > 0 order by att.attnum
Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂