On Thu, Jul 10, 2014 at 06:38:26PM -0400, Bruce Momjian wrote: > On Thu, Jul 10, 2014 at 06:17:14PM -0400, Bruce Momjian wrote: > > Well, we are going to need to call internal C functions, often bypassing > > their typical call sites and the assumption about locking, etc. Perhaps > > this could be done from a plpgsql function. We could add and drop a > > dummy column to force TOAST table creation --- we would then only need a > > way to detect if a function _needs_ a TOAST table, which was skipped in > > binary upgrade mode previously. > > > > That might be a minimalistic approach. > > I have thought some more on this. I thought I would need to open > pg_class in C and do complex backend stuff, but I now realize I can do > it from libpq, and just call ALTER TABLE and I think that always > auto-checks if a TOAST table is needed. All I have to do is query > pg_class from libpq, then construct ALTER TABLE commands for each item, > and it will optionally create the TOAST table if needed. I just have to > use a no-op ALTER TABLE command, like SET STATISTICS.
Attached is a completed patch which handles oid conflicts in pg_class and pg_type for TOAST tables that were not needed in the old cluster but are needed in the new one. I was able to recreate a failure case and this fixed it. The patch need to be backpatched because I am getting more-frequent bug reports from users using pg_upgrade to leave now-end-of-life'ed 8.4. There is not a good work-around for pg_upgrade failures without this fix, but at least pg_upgrade throws an error. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. +
diff --git a/contrib/pg_upgrade/dump.c b/contrib/pg_upgrade/dump.c new file mode 100644 index b112f3a..642dd5d *** a/contrib/pg_upgrade/dump.c --- b/contrib/pg_upgrade/dump.c *************** *** 12,17 **** --- 12,19 ---- #include "pg_upgrade.h" #include <sys/types.h> + #include "catalog/binary_upgrade.h" + void generate_old_dump(void) *************** generate_old_dump(void) *** 67,69 **** --- 69,139 ---- end_progress_output(); check_ok(); } + + + /* + * It is possible for there to be a mismatch in the need for TOAST tables + * between the old and new servers, e.g. some pre-9.1 tables didn't need + * TOAST tables but will need them in 9.1+. (There are also opposite cases, + * but these are handled by setting binary_upgrade_next_toast_pg_class_oid.) + * + * We can't allow the TOAST table to be created by pg_dump with a + * pg_dump-assigned oid because it might conflict with a later table that + * uses that oid, causing a "file exists" error for pg_class conflicts, and + * a "duplicate oid" error for pg_type conflicts. (TOAST tables need pg_type + * entries.) + * + * Therefore, a backend in binary-upgrade mode will not create a TOAST + * table unless an OID as passed in via pg_upgrade_support functions. + * This function is called after the restore and uses ALTER TABLE to + * auto-create any needed TOAST tables which will not conflict with + * restored oids. + */ + void + optionally_create_toast_tables(void) + { + int dbnum; + + prep_status("Creating newly-required TOAST tables"); + + for (dbnum = 0; dbnum < new_cluster.dbarr.ndbs; dbnum++) + { + PGresult *res; + int ntups; + int rowno; + int i_nspname, + i_relname; + DbInfo *active_db = &new_cluster.dbarr.dbs[dbnum]; + PGconn *conn = connectToServer(&new_cluster, active_db->db_name); + + res = executeQueryOrDie(conn, + "SELECT n.nspname, c.relname " + "FROM pg_catalog.pg_class c, " + " pg_catalog.pg_namespace n " + "WHERE c.relnamespace = n.oid AND " + " n.nspname NOT IN ('pg_catalog', 'information_schema') AND " + "c.relkind IN ('r', 'm') AND " + "c.reltoastrelid = 0"); + + ntups = PQntuples(res); + i_nspname = PQfnumber(res, "nspname"); + i_relname = PQfnumber(res, "relname"); + for (rowno = 0; rowno < ntups; rowno++) + { + /* enable auto-oid-numbered TOAST creation if needed */ + PQclear(executeQueryOrDie(conn, "SELECT binary_upgrade.set_next_toast_pg_class_oid('%d'::pg_catalog.oid);", + OPTIONALLY_CREATE_TOAST_OID)); + + /* dummy command that also triggers check for required TOAST table */ + PQclear(executeQueryOrDie(conn, "ALTER TABLE %s.%s RESET (binary_upgrade_dummy_option);", + quote_identifier(PQgetvalue(res, rowno, i_nspname)), + quote_identifier(PQgetvalue(res, rowno, i_relname)))); + } + + PQclear(res); + + PQfinish(conn); + } + + check_ok(); + } diff --git a/contrib/pg_upgrade/pg_upgrade.c b/contrib/pg_upgrade/pg_upgrade.c new file mode 100644 index 3e97b66..49ea873 *** a/contrib/pg_upgrade/pg_upgrade.c --- b/contrib/pg_upgrade/pg_upgrade.c *************** create_new_objects(void) *** 363,368 **** --- 363,370 ---- if (GET_MAJOR_VERSION(old_cluster.major_version) < 903) set_frozenxids(true); + optionally_create_toast_tables(); + /* regenerate now that we have objects in the databases */ get_db_and_rel_infos(&new_cluster); diff --git a/contrib/pg_upgrade/pg_upgrade.h b/contrib/pg_upgrade/pg_upgrade.h new file mode 100644 index 61e5de0..1175604 *** a/contrib/pg_upgrade/pg_upgrade.h --- b/contrib/pg_upgrade/pg_upgrade.h *************** void disable_old_cluster(void); *** 336,341 **** --- 336,342 ---- /* dump.c */ void generate_old_dump(void); + void optionally_create_toast_tables(void); /* exec.c */ diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c new file mode 100644 index bdfeb90..e2549b2 *** a/src/backend/catalog/toasting.c --- b/src/backend/catalog/toasting.c *************** create_toast_table(Relation rel, Oid toa *** 165,180 **** if (rel->rd_rel->reltoastrelid != InvalidOid) return false; ! /* ! * Check to see whether the table actually needs a TOAST table. ! * ! * If an update-in-place toast relfilenode is specified, force toast file ! * creation even if it seems not to need one. ! */ ! if (!needs_toast_table(rel) && ! (!IsBinaryUpgrade || ! !OidIsValid(binary_upgrade_next_toast_pg_class_oid))) ! return false; /* * If requested check lockmode is sufficient. This is a cross check in --- 165,211 ---- if (rel->rd_rel->reltoastrelid != InvalidOid) return false; ! if (!IsBinaryUpgrade) ! { ! if (!needs_toast_table(rel)) ! return false; ! } ! else ! { ! /* ! * Check to see whether the table needs a TOAST table. ! * ! * If an update-in-place TOAST relfilenode is specified, force TOAST file ! * creation even if it seems not to need one. This handles the case ! * where the old cluster needed a TOAST table but the new cluster ! * would not normally create one. ! */ ! ! /* ! * If a TOAST oid is not specified, skip TOAST creation as we will do ! * it later so we don't create a TOAST table whose OID later conflicts ! * with a user-supplied OID. This handles cases where the old cluster ! * didn't need a TOAST table, but the new cluster does. ! */ ! if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid)) ! return false; ! ! /* ! * If a special TOAST value has been passed in, it means we are in ! * cleanup mode --- we are creating needed TOAST tables after all user ! * tables with specified OIDs have been created. We let the system ! * assign a TOAST oid for us. The tables are empty so the missing ! * TOAST tables were not a problem. ! */ ! if (binary_upgrade_next_toast_pg_class_oid == OPTIONALLY_CREATE_TOAST_OID) ! { ! /* clear as it is not to be used; it is just a flag */ ! binary_upgrade_next_toast_pg_class_oid = InvalidOid; ! ! if (!needs_toast_table(rel)) ! return false; ! } ! } /* * If requested check lockmode is sufficient. This is a cross check in diff --git a/src/include/catalog/binary_upgrade.h b/src/include/catalog/binary_upgrade.h new file mode 100644 index f39017c..63fa85e *** a/src/include/catalog/binary_upgrade.h --- b/src/include/catalog/binary_upgrade.h *************** *** 14,19 **** --- 14,24 ---- #ifndef BINARY_UPGRADE_H #define BINARY_UPGRADE_H + #include "catalog/pg_authid.h" + + /* pick a OID that will never be used for TOAST tables */ + #define OPTIONALLY_CREATE_TOAST_OID BOOTSTRAP_SUPERUSERID + extern PGDLLIMPORT Oid binary_upgrade_next_pg_type_oid; extern PGDLLIMPORT Oid binary_upgrade_next_array_pg_type_oid; extern PGDLLIMPORT Oid binary_upgrade_next_toast_pg_type_oid;
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