pgsql: Add the ability to create indexes 'concurrently', that is,

Log Message:
-----------
Add the ability to create indexes 'concurrently', that is, without
blocking concurrent writes to the table. Greg Stark, with a little help
from Tom Lane.

Modified Files:
--------------
pgsql/doc/src/sgml:
catalogs.sgml (r2.129 -> r2.130)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml.diff?r1=2.129&r2=2.130)
indexam.sgml (r2.16 -> r2.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/indexam.sgml.diff?r1=2.16&r2=2.17)
indices.sgml (r1.57 -> r1.58)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/indices.sgml.diff?r1=1.57&r2=1.58)
mvcc.sgml (r2.56 -> r2.57)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/mvcc.sgml.diff?r1=2.56&r2=2.57)
pgsql/doc/src/sgml/ref:
create_index.sgml (r1.55 -> r1.56)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_index.sgml.diff?r1=1.55&r2=1.56)
reindex.sgml (r1.31 -> r1.32)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/reindex.sgml.diff?r1=1.31&r2=1.32)
pgsql/src/backend/access/nbtree:
nbtinsert.c (r1.142 -> r1.143)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtinsert.c.diff?r1=1.142&r2=1.143)
pgsql/src/backend/bootstrap:
bootparse.y (r1.83 -> r1.84)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootparse.y.diff?r1=1.83&r2=1.84)
pgsql/src/backend/catalog:
index.c (r1.272 -> r1.273)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c.diff?r1=1.272&r2=1.273)
toasting.c (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/toasting.c.diff?r1=1.1&r2=1.2)
pgsql/src/backend/commands:
indexcmds.c (r1.146 -> r1.147)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/indexcmds.c.diff?r1=1.146&r2=1.147)
tablecmds.c (r1.200 -> r1.201)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c.diff?r1=1.200&r2=1.201)
pgsql/src/backend/nodes:
copyfuncs.c (r1.348 -> r1.349)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/copyfuncs.c.diff?r1=1.348&r2=1.349)
equalfuncs.c (r1.282 -> r1.283)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/equalfuncs.c.diff?r1=1.282&r2=1.283)
outfuncs.c (r1.283 -> r1.284)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/outfuncs.c.diff?r1=1.283&r2=1.284)
pgsql/src/backend/optimizer/util:
plancat.c (r1.124 -> r1.125)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/plancat.c.diff?r1=1.124&r2=1.125)
pgsql/src/backend/parser:
analyze.c (r1.347 -> r1.348)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/analyze.c.diff?r1=1.347&r2=1.348)
gram.y (r2.557 -> r2.558)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.557&r2=2.558)
keywords.c (r1.175 -> r1.176)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/keywords.c.diff?r1=1.175&r2=1.176)
pgsql/src/backend/storage/page:
itemptr.c (r1.17 -> r1.18)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/page/itemptr.c.diff?r1=1.17&r2=1.18)
pgsql/src/backend/tcop:
utility.c (r1.266 -> r1.267)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/utility.c.diff?r1=1.266&r2=1.267)
pgsql/src/backend/utils/adt:
tid.c (r1.54 -> r1.55)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/tid.c.diff?r1=1.54&r2=1.55)
pgsql/src/bin/psql:
common.c (r1.124 -> r1.125)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/common.c.diff?r1=1.124&r2=1.125)
describe.c (r1.142 -> r1.143)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/describe.c.diff?r1=1.142&r2=1.143)
pgsql/src/include/catalog:
catversion.h (r1.352 -> r1.353)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.352&r2=1.353)
index.h (r1.70 -> r1.71)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/index.h.diff?r1=1.70&r2=1.71)
pg_attribute.h (r1.123 -> r1.124)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_attribute.h.diff?r1=1.123&r2=1.124)
pg_index.h (r1.39 -> r1.40)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_index.h.diff?r1=1.39&r2=1.40)
pgsql/src/include/commands:
defrem.h (r1.75 -> r1.76)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/commands/defrem.h.diff?r1=1.75&r2=1.76)
pgsql/src/include/nodes:
execnodes.h (r1.159 -> r1.160)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/execnodes.h.diff?r1=1.159&r2=1.160)
parsenodes.h (r1.324 -> r1.325)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/parsenodes.h.diff?r1=1.324&r2=1.325)
pgsql/src/include/storage:
itemptr.h (r1.28 -> r1.29)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/itemptr.h.diff?r1=1.28&r2=1.29)
pgsql/src/test/regress/expected:
create_index.out (r1.20 -> r1.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/create_index.out.diff?r1=1.20&r2=1.21)
pgsql/src/test/regress/sql:
create_index.sql (r1.19 -> r1.20)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/create_index.sql.diff?r1=1.19&r2=1.20)