On Mon, Dec 05, 2011 at 05:06:37PM -0500, Bruce Momjian wrote: > Pg_upgrade has the following check to make sure the cluster is safe for > upgrading: > > res = executeQueryOrDie(conn, > "SELECT n.nspname, c.relname, a.attname > " > "FROM pg_catalog.pg_class c, " > " pg_catalog.pg_namespace n, " > " pg_catalog.pg_attribute a " > "WHERE c.oid = a.attrelid AND " > " NOT a.attisdropped AND " > " a.atttypid IN ( " > " 'pg_catalog.regproc'::pg_catalog.regtype, " > " 'pg_catalog.regprocedure'::pg_catalog.regtype, " > " 'pg_catalog.regoper'::pg_catalog.regtype, " > " 'pg_catalog.regoperator'::pg_catalog.regtype, " > /* regclass.oid is preserved, so 'regclass' is OK */ > /* regtype.oid is preserved, so 'regtype' is OK */ > " 'pg_catalog.regconfig'::pg_catalog.regtype, " > " 'pg_catalog.regdictionary'::pg_catalog.regtype) AND > " > " c.relnamespace = n.oid AND " > " n.nspname != 'pg_catalog' AND " > " n.nspname != 'information_schema'"); > > Based on a report from EnterpriseDB, I noticed that we check all > pg_class entries, while there are cases where this is unnecessary > because there is no data behind the entry, e.g. views. Here are the > relkinds supported: > > #define RELKIND_RELATION 'r' /* ordinary table */ > #define RELKIND_INDEX 'i' /* secondary index */ > #define RELKIND_SEQUENCE 'S' /* sequence object */ > #define RELKIND_TOASTVALUE 't' /* for out-of-line > values */ > #define RELKIND_VIEW 'v' /* view */ > #define RELKIND_COMPOSITE_TYPE 'c' /* composite type */ > #define RELKIND_FOREIGN_TABLE 'f' /* foreign table */ > #define RELKIND_UNCATALOGED 'u' /* not yet cataloged */ > > What types, other than views, can we skip in this query?
RELKIND_UNCATALOGED should never appear on disk, and RELKIND_SEQUENCE and RELKIND_TOASTVALUE do not allow adding columns or changing column types. We might as well keep validating them. RELKIND_RELATION and RELKIND_INDEX have storage, so we must check those. The remaining three relkinds (RELKIND_VIEW, RELKIND_COMPOSITE_TYPE, RELKIND_FOREIGN_TABLE) have no storage, but all are usable as column types in other relations that do have storage. You could skip them iff they're unused that way, per a check like find_composite_type_dependencies(). -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
