pgsql: Create a "relation mapping" infrastructure to support changing

Log Message:
-----------
Create a "relation mapping" infrastructure to support changing the relfilenodes
of shared or nailed system catalogs. This has two key benefits:

* The new CLUSTER-based VACUUM FULL can be applied safely to all catalogs.

* We no longer have to use an unsafe reindex-in-place approach for reindexing
shared catalogs.

CLUSTER on nailed catalogs now works too, although I left it disabled on
shared catalogs because the resulting pg_index.indisclustered update would
only be visible in one database.

Since reindexing shared system catalogs is now fully transactional and
crash-safe, the former special cases in REINDEX behavior have been removed;
shared catalogs are treated the same as non-shared.

This commit does not do anything about the recently-discussed problem of
deadlocks between VACUUM FULL/CLUSTER on a system catalog and other
concurrent queries; will address that in a separate patch. As a stopgap,
parallel_schedule has been tweaked to run vacuum.sql by itself, to avoid
such failures during the regression tests.

Modified Files:
--------------
pgsql/contrib/oid2name:
oid2name.c (r1.36 -> r1.37)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/contrib/oid2name/oid2name.c?r1=1.36&r2=1.37)
pgsql/doc/src/sgml:
catalogs.sgml (r2.220 -> r2.221)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml?r1=2.220&r2=2.221)
diskusage.sgml (r1.19 -> r1.20)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/diskusage.sgml?r1=1.19&r2=1.20)
func.sgml (r1.500 -> r1.501)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.500&r2=1.501)
pgbuffercache.sgml (r2.5 -> r2.6)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/pgbuffercache.sgml?r1=2.5&r2=2.6)
storage.sgml (r1.30 -> r1.31)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/storage.sgml?r1=1.30&r2=1.31)
pgsql/doc/src/sgml/ref:
cluster.sgml (r1.47 -> r1.48)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/cluster.sgml?r1=1.47&r2=1.48)
reindex.sgml (r1.38 -> r1.39)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/reindex.sgml?r1=1.38&r2=1.39)
pgsql/src/backend/access/index:
genam.c (r1.79 -> r1.80)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/index/genam.c?r1=1.79&r2=1.80)
pgsql/src/backend/access/transam:
rmgr.c (r1.28 -> r1.29)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/rmgr.c?r1=1.28&r2=1.29)
xact.c (r1.282 -> r1.283)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.282&r2=1.283)
xlog.c (r1.366 -> r1.367)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c?r1=1.366&r2=1.367)
pgsql/src/backend/bootstrap:
bootparse.y (r1.104 -> r1.105)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootparse.y?r1=1.104&r2=1.105)
bootstrap.c (r1.258 -> r1.259)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootstrap.c?r1=1.258&r2=1.259)
pgsql/src/backend/catalog:
catalog.c (r1.87 -> r1.88)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/catalog.c?r1=1.87&r2=1.88)
heap.c (r1.369 -> r1.370)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/heap.c?r1=1.369&r2=1.370)
index.c (r1.332 -> r1.333)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c?r1=1.332&r2=1.333)
storage.c (r1.7 -> r1.8)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/storage.c?r1=1.7&r2=1.8)
toasting.c (r1.29 -> r1.30)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/toasting.c?r1=1.29&r2=1.30)
pgsql/src/backend/commands:
cluster.c (r1.197 -> r1.198)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/cluster.c?r1=1.197&r2=1.198)
indexcmds.c (r1.190 -> r1.191)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/indexcmds.c?r1=1.190&r2=1.191)
tablecmds.c (r1.324 -> r1.325)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.324&r2=1.325)
vacuum.c (r1.403 -> r1.404)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c?r1=1.403&r2=1.404)
pgsql/src/backend/executor:
execMain.c (r1.344 -> r1.345)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c?r1=1.344&r2=1.345)
pgsql/src/backend/parser:
parse_clause.c (r1.195 -> r1.196)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/parse_clause.c?r1=1.195&r2=1.196)
pgsql/src/backend/utils/adt:
dbsize.c (r1.28 -> r1.29)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/dbsize.c?r1=1.28&r2=1.29)
pgsql/src/backend/utils/cache:
Makefile (r1.25 -> r1.26)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/Makefile?r1=1.25&r2=1.26)
catcache.c (r1.148 -> r1.149)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/catcache.c?r1=1.148&r2=1.149)
inval.c (r1.93 -> r1.94)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/inval.c?r1=1.93&r2=1.94)
relcache.c (r1.302 -> r1.303)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relcache.c?r1=1.302&r2=1.303)
pgsql/src/backend/utils/init:
miscinit.c (r1.180 -> r1.181)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c?r1=1.180&r2=1.181)
pgsql/src/bin/pg_dump:
pg_dump.c (r1.569 -> r1.570)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c?r1=1.569&r2=1.570)
pgsql/src/include/access:
rmgr.h (r1.20 -> r1.21)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/access/rmgr.h?r1=1.20&r2=1.21)
pgsql/src/include/catalog:
catalog.h (r1.47 -> r1.48)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catalog.h?r1=1.47&r2=1.48)
catversion.h (r1.582 -> r1.583)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.582&r2=1.583)
heap.h (r1.96 -> r1.97)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/heap.h?r1=1.96&r2=1.97)
index.h (r1.81 -> r1.82)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/index.h?r1=1.81&r2=1.82)
pg_class.h (r1.120 -> r1.121)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_class.h?r1=1.120&r2=1.121)
pg_proc.h (r1.567 -> r1.568)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.567&r2=1.568)
storage.h (r1.4 -> r1.5)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/storage.h?r1=1.4&r2=1.5)
pgsql/src/include/commands:
cluster.h (r1.39 -> r1.40)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/cluster.h?r1=1.39&r2=1.40)
pgsql/src/include:
miscadmin.h (r1.217 -> r1.218)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/miscadmin.h?r1=1.217&r2=1.218)
pgsql/src/include/storage:
lwlock.h (r1.43 -> r1.44)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/lwlock.h?r1=1.43&r2=1.44)
relfilenode.h (r1.24 -> r1.25)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/relfilenode.h?r1=1.24&r2=1.25)
sinval.h (r1.56 -> r1.57)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/sinval.h?r1=1.56&r2=1.57)
pgsql/src/include/utils:
builtins.h (r1.346 -> r1.347)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h?r1=1.346&r2=1.347)
catcache.h (r1.69 -> r1.70)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/catcache.h?r1=1.69&r2=1.70)
inval.h (r1.47 -> r1.48)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/inval.h?r1=1.47&r2=1.48)
rel.h (r1.121 -> r1.122)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/rel.h?r1=1.121&r2=1.122)
relcache.h (r1.67 -> r1.68)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/relcache.h?r1=1.67&r2=1.68)
pgsql/src/test/regress/expected:
vacuum.out (r1.3 -> r1.4)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/vacuum.out?r1=1.3&r2=1.4)
pgsql/src/test/regress:
parallel_schedule (r1.58 -> r1.59)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/parallel_schedule?r1=1.58&r2=1.59)

Added Files:
-----------
pgsql/src/backend/utils/cache:
relmapper.c (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relmapper.c?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql/src/include/utils:
relmapper.h (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/relmapper.h?rev=1.1&content-type=text/x-cvsweb-markup)