DELETE FROM revision_materialized_prefix WHERE prefix LIKE 'as:%';

ALTER TABLE revision_materialized_prefix
    ALTER COLUMN prefix TYPE CIDR USING prefix::cidr;

ALTER TABLE module_as_entry ADD COLUMN prefix CIDR;
ALTER TABLE module_as_entry ALTER COLUMN asn DROP NOT NULL;
ALTER TABLE module_as_entry
    ADD CONSTRAINT module_as_entry_asn_or_prefix_chk CHECK (asn IS NOT NULL OR prefix IS NOT NULL);