Un-break pg_upgrade from pre-v12 servers.

I neglected to test this scenario while preparing commit f3faf35f3,
so of course it was broken, thanks to some very obscure and undocumented
code in pg_dump.  Pre-v12 databases might have toast tables attached to
partitioned tables, which we need to ignore since newer servers never
create such useless toast tables.  There was a filter for this case in
binary_upgrade_set_type_oids_by_rel_oid(), which appeared to just
prevent the pg_type OID from being copied.  But actually it managed to
prevent the toast table from being created at all --- or it did before
I took out that logic.  But that was a fundamentally bizarre place to be
making the test in the first place.  The place where the filter should
have been, one would think, is binary_upgrade_set_pg_class_oids(), so
add it there.

While at it, reorganize binary_upgrade_set_pg_class_oids() so that it
doesn't make a completely useless query when it knows it's being
invoked for an index.  And correct a comment that mis-described the
scenario where we need to force creation of a TOAST table.

Per buildfarm.
This commit is contained in:
Tom Lane 2020-07-07 18:10:42 -04:00
parent f3faf35f37
commit 3f96af4619
1 changed files with 44 additions and 31 deletions

View File

@ -4525,43 +4525,56 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
PQExpBuffer upgrade_buffer, Oid pg_class_oid,
bool is_index)
{
PQExpBuffer upgrade_query = createPQExpBuffer();
PGresult *upgrade_res;
Oid pg_class_reltoastrelid;
Oid pg_index_indexrelid;
appendPQExpBuffer(upgrade_query,
"SELECT c.reltoastrelid, i.indexrelid "
"FROM pg_catalog.pg_class c LEFT JOIN "
"pg_catalog.pg_index i ON (c.reltoastrelid = i.indrelid AND i.indisvalid) "
"WHERE c.oid = '%u'::pg_catalog.oid;",
pg_class_oid);
upgrade_res = ExecuteSqlQueryForSingleRow(fout, upgrade_query->data);
pg_class_reltoastrelid = atooid(PQgetvalue(upgrade_res, 0, PQfnumber(upgrade_res, "reltoastrelid")));
pg_index_indexrelid = atooid(PQgetvalue(upgrade_res, 0, PQfnumber(upgrade_res, "indexrelid")));
appendPQExpBufferStr(upgrade_buffer,
"\n-- For binary upgrade, must preserve pg_class oids\n");
if (!is_index)
{
PQExpBuffer upgrade_query = createPQExpBuffer();
PGresult *upgrade_res;
Oid pg_class_reltoastrelid;
char pg_class_relkind;
Oid pg_index_indexrelid;
appendPQExpBuffer(upgrade_buffer,
"SELECT pg_catalog.binary_upgrade_set_next_heap_pg_class_oid('%u'::pg_catalog.oid);\n",
pg_class_oid);
/* only tables have toast tables, not indexes */
if (OidIsValid(pg_class_reltoastrelid))
{
/*
* One complexity is that the table definition might not require
* the creation of a TOAST table, and the TOAST table might have
* been created long after table creation, when the table was
* loaded with wide data. By setting the TOAST oid we force
* creation of the TOAST heap and TOAST index by the backend so we
* can cleanly copy the files during binary upgrade.
*/
/*
* Preserve the OIDs of the table's toast table and index, if any.
* Indexes cannot have toast tables, so we need not make this probe in
* the index code path.
*
* One complexity is that the current table definition might not
* require the creation of a TOAST table, but the old database might
* have a TOAST table that was created earlier, before some wide
* columns were dropped. By setting the TOAST oid we force creation
* of the TOAST heap and index by the new backend, so we can copy the
* files during binary upgrade without worrying about this case.
*/
appendPQExpBuffer(upgrade_query,
"SELECT c.reltoastrelid, c.relkind, i.indexrelid "
"FROM pg_catalog.pg_class c LEFT JOIN "
"pg_catalog.pg_index i ON (c.reltoastrelid = i.indrelid AND i.indisvalid) "
"WHERE c.oid = '%u'::pg_catalog.oid;",
pg_class_oid);
upgrade_res = ExecuteSqlQueryForSingleRow(fout, upgrade_query->data);
pg_class_reltoastrelid = atooid(PQgetvalue(upgrade_res, 0,
PQfnumber(upgrade_res, "reltoastrelid")));
pg_class_relkind = *PQgetvalue(upgrade_res, 0,
PQfnumber(upgrade_res, "relkind"));
pg_index_indexrelid = atooid(PQgetvalue(upgrade_res, 0,
PQfnumber(upgrade_res, "indexrelid")));
/*
* In a pre-v12 database, partitioned tables might be marked as having
* toast tables, but we should ignore them if so.
*/
if (OidIsValid(pg_class_reltoastrelid) &&
pg_class_relkind != RELKIND_PARTITIONED_TABLE)
{
appendPQExpBuffer(upgrade_buffer,
"SELECT pg_catalog.binary_upgrade_set_next_toast_pg_class_oid('%u'::pg_catalog.oid);\n",
pg_class_reltoastrelid);
@ -4571,6 +4584,9 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
"SELECT pg_catalog.binary_upgrade_set_next_index_pg_class_oid('%u'::pg_catalog.oid);\n",
pg_index_indexrelid);
}
PQclear(upgrade_res);
destroyPQExpBuffer(upgrade_query);
}
else
appendPQExpBuffer(upgrade_buffer,
@ -4578,9 +4594,6 @@ binary_upgrade_set_pg_class_oids(Archive *fout,
pg_class_oid);
appendPQExpBufferChar(upgrade_buffer, '\n');
PQclear(upgrade_res);
destroyPQExpBuffer(upgrade_query);
}
/*