pgsql-server: Nested transactions.

Log Message:
-----------
Nested transactions. There is still much left to do, especially on the
performance front, but with feature freeze upon us I think it's time to
drive a stake in the ground and say that this will be in 7.5.

Alvaro Herrera, with some help from Tom Lane.

Modified Files:
--------------
pgsql-server/contrib/userlock:
user_locks.c (r1.11 -> r1.12)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/contrib/userlock/user_locks.c.diff?r1=1.11&r2=1.12)
pgsql-server/src/backend/access/gist:
gistscan.c (r1.51 -> r1.52)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/gist/gistscan.c.diff?r1=1.51&r2=1.52)
pgsql-server/src/backend/access/hash:
hashscan.c (r1.33 -> r1.34)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/hash/hashscan.c.diff?r1=1.33&r2=1.34)
pgsql-server/src/backend/access/rtree:
rtscan.c (r1.51 -> r1.52)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/rtree/rtscan.c.diff?r1=1.51&r2=1.52)
pgsql-server/src/backend/access/transam:
Makefile (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/Makefile.diff?r1=1.18&r2=1.19)
clog.c (r1.20 -> r1.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/clog.c.diff?r1=1.20&r2=1.21)
rmgr.c (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/rmgr.c.diff?r1=1.12&r2=1.13)
slru.c (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/slru.c.diff?r1=1.16&r2=1.17)
transam.c (r1.56 -> r1.57)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/transam.c.diff?r1=1.56&r2=1.57)
varsup.c (r1.55 -> r1.56)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/varsup.c.diff?r1=1.55&r2=1.56)
xact.c (r1.168 -> r1.169)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/xact.c.diff?r1=1.168&r2=1.169)
xlog.c (r1.146 -> r1.147)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/xlog.c.diff?r1=1.146&r2=1.147)
pgsql-server/src/backend/commands:
async.c (r1.112 -> r1.113)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/async.c.diff?r1=1.112&r2=1.113)
tablecmds.c (r1.117 -> r1.118)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/tablecmds.c.diff?r1=1.117&r2=1.118)
trigger.c (r1.165 -> r1.166)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/trigger.c.diff?r1=1.165&r2=1.166)
vacuum.c (r1.281 -> r1.282)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/vacuum.c.diff?r1=1.281&r2=1.282)
variable.c (r1.97 -> r1.98)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/commands/variable.c.diff?r1=1.97&r2=1.98)
pgsql-server/src/backend/executor:
spi.c (r1.118 -> r1.119)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/executor/spi.c.diff?r1=1.118&r2=1.119)
pgsql-server/src/backend/postmaster:
pgstat.c (r1.76 -> r1.77)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/postmaster/pgstat.c.diff?r1=1.76&r2=1.77)
pgsql-server/src/backend/storage/buffer:
bufmgr.c (r1.171 -> r1.172)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/buffer/bufmgr.c.diff?r1=1.171&r2=1.172)
pgsql-server/src/backend/storage/ipc:
ipci.c (r1.68 -> r1.69)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/ipc/ipci.c.diff?r1=1.68&r2=1.69)
sinval.c (r1.64 -> r1.65)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/ipc/sinval.c.diff?r1=1.64&r2=1.65)
pgsql-server/src/backend/storage/lmgr:
lmgr.c (r1.63 -> r1.64)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/lmgr/lmgr.c.diff?r1=1.63&r2=1.64)
lock.c (r1.133 -> r1.134)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/lmgr/lock.c.diff?r1=1.133&r2=1.134)
lwlock.c (r1.20 -> r1.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/lmgr/lwlock.c.diff?r1=1.20&r2=1.21)
proc.c (r1.148 -> r1.149)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/lmgr/proc.c.diff?r1=1.148&r2=1.149)
pgsql-server/src/backend/storage/smgr:
smgr.c (r1.74 -> r1.75)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/storage/smgr/smgr.c.diff?r1=1.74&r2=1.75)
pgsql-server/src/backend/tcop:
postgres.c (r1.421 -> r1.422)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/tcop/postgres.c.diff?r1=1.421&r2=1.422)
pgsql-server/src/backend/utils/cache:
catcache.c (r1.112 -> r1.113)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/cache/catcache.c.diff?r1=1.112&r2=1.113)
inval.c (r1.62 -> r1.63)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/cache/inval.c.diff?r1=1.62&r2=1.63)
relcache.c (r1.205 -> r1.206)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/cache/relcache.c.diff?r1=1.205&r2=1.206)
pgsql-server/src/backend/utils/init:
postinit.c (r1.134 -> r1.135)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/init/postinit.c.diff?r1=1.134&r2=1.135)
pgsql-server/src/backend/utils/misc:
README (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/misc/README.diff?r1=1.4&r2=1.5)
guc.c (r1.211 -> r1.212)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/misc/guc.c.diff?r1=1.211&r2=1.212)
pgsql-server/src/backend/utils/mmgr:
README (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/mmgr/README.diff?r1=1.6&r2=1.7)
mcxt.c (r1.45 -> r1.46)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/mmgr/mcxt.c.diff?r1=1.45&r2=1.46)
portalmem.c (r1.65 -> r1.66)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/mmgr/portalmem.c.diff?r1=1.65&r2=1.66)
pgsql-server/src/backend/utils/time:
tqual.c (r1.72 -> r1.73)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/utils/time/tqual.c.diff?r1=1.72&r2=1.73)
pgsql-server/src/bin/initdb:
initdb.c (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/initdb/initdb.c.diff?r1=1.40&r2=1.41)
pgsql-server/src/include/access:
clog.h (r1.8 -> r1.9)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/clog.h.diff?r1=1.8&r2=1.9)
gistscan.h (r1.22 -> r1.23)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/gistscan.h.diff?r1=1.22&r2=1.23)
hash.h (r1.54 -> r1.55)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/hash.h.diff?r1=1.54&r2=1.55)
htup.h (r1.65 -> r1.66)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/htup.h.diff?r1=1.65&r2=1.66)
rmgr.h (r1.10 -> r1.11)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/rmgr.h.diff?r1=1.10&r2=1.11)
rtree.h (r1.32 -> r1.33)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/rtree.h.diff?r1=1.32&r2=1.33)
slru.h (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/slru.h.diff?r1=1.6&r2=1.7)
transam.h (r1.48 -> r1.49)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/transam.h.diff?r1=1.48&r2=1.49)
xact.h (r1.63 -> r1.64)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/xact.h.diff?r1=1.63&r2=1.64)
xlog.h (r1.51 -> r1.52)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/xlog.h.diff?r1=1.51&r2=1.52)
pgsql-server/src/include/catalog:
catversion.h (r1.240 -> r1.241)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/catalog/catversion.h.diff?r1=1.240&r2=1.241)
pgsql-server/src/include/commands:
async.h (r1.24 -> r1.25)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/commands/async.h.diff?r1=1.24&r2=1.25)
tablecmds.h (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/commands/tablecmds.h.diff?r1=1.16&r2=1.17)
trigger.h (r1.45 -> r1.46)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/commands/trigger.h.diff?r1=1.45&r2=1.46)
pgsql-server/src/include/executor:
spi.h (r1.44 -> r1.45)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/executor/spi.h.diff?r1=1.44&r2=1.45)
spi_priv.h (r1.18 -> r1.19)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/executor/spi_priv.h.diff?r1=1.18&r2=1.19)
pgsql-server/src/include/storage:
bufmgr.h (r1.82 -> r1.83)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/storage/bufmgr.h.diff?r1=1.82&r2=1.83)
bufpage.h (r1.58 -> r1.59)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/storage/bufpage.h.diff?r1=1.58&r2=1.59)
lock.h (r1.77 -> r1.78)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/storage/lock.h.diff?r1=1.77&r2=1.78)
proc.h (r1.67 -> r1.68)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/storage/proc.h.diff?r1=1.67&r2=1.68)
smgr.h (r1.44 -> r1.45)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/storage/smgr.h.diff?r1=1.44&r2=1.45)
pgsql-server/src/include/utils:
catcache.h (r1.48 -> r1.49)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/catcache.h.diff?r1=1.48&r2=1.49)
guc.h (r1.47 -> r1.48)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/guc.h.diff?r1=1.47&r2=1.48)
guc_tables.h (r1.11 -> r1.12)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/guc_tables.h.diff?r1=1.11&r2=1.12)
inval.h (r1.31 -> r1.32)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/inval.h.diff?r1=1.31&r2=1.32)
memutils.h (r1.55 -> r1.56)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/memutils.h.diff?r1=1.55&r2=1.56)
portal.h (r1.48 -> r1.49)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/portal.h.diff?r1=1.48&r2=1.49)
rel.h (r1.74 -> r1.75)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/rel.h.diff?r1=1.74&r2=1.75)
relcache.h (r1.40 -> r1.41)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/utils/relcache.h.diff?r1=1.40&r2=1.41)
pgsql-server/src/test/regress/expected:
transactions.out (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/test/regress/expected/transactions.out.diff?r1=1.3&r2=1.4)
without_oid.out (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/test/regress/expected/without_oid.out.diff?r1=1.3&r2=1.4)
pgsql-server/src/test/regress/sql:
transactions.sql (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/test/regress/sql/transactions.sql.diff?r1=1.3&r2=1.4)
without_oid.sql (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/test/regress/sql/without_oid.sql.diff?r1=1.3&r2=1.4)

Added Files:
-----------
pgsql-server/src/backend/access/transam:
subtrans.c (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/access/transam/subtrans.c?rev=1.1&content-type=text/x-cvsweb-markup)
pgsql-server/src/include/access:
subtrans.h (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/access/subtrans.h?rev=1.1&content-type=text/x-cvsweb-markup)