pgsql: Add ALTER SUBSCRIPTION ... SKIP.

Add ALTER SUBSCRIPTION ... SKIP.

This feature allows skipping the transaction on subscriber nodes.

If incoming change violates any constraint, logical replication stops
until it's resolved. Currently, users need to either manually resolve the
conflict by updating a subscriber-side database or by using function
pg_replication_origin_advance() to skip the conflicting transaction. This
commit introduces a simpler way to skip the conflicting transactions.

The user can specify LSN by ALTER SUBSCRIPTION ... SKIP (lsn = XXX),
which allows the apply worker to skip the transaction finished at
specified LSN. The apply worker skips all data modification changes within
the transaction.

Author: Masahiko Sawada
Reviewed-by: Takamichi Osumi, Hou Zhijie, Peter Eisentraut, Amit Kapila, Shi Yu, Vignesh C, Greg Nancarrow, Haiying
Tang,Euler Taveira 
Discussion: https://postgr.es/m/CAD21AoDeScrsHhLyEPYqN3sydg6PxAPVBboK=30xJfUVihNZDA@mail.gmail.com

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/208c5d65bbd60e33e272964578cb74182ac726a8

Modified Files
--------------
doc/src/sgml/catalogs.sgml                      |  10 +
doc/src/sgml/logical-replication.sgml           |  27 +--
doc/src/sgml/ref/alter_subscription.sgml        |  42 +++++
src/backend/catalog/pg_subscription.c           |   1 +
src/backend/catalog/system_views.sql            |   2 +-
src/backend/commands/subscriptioncmds.c         |  73 ++++++++
src/backend/parser/gram.y                       |   9 +
src/backend/replication/logical/worker.c        | 233 +++++++++++++++++++++++-
src/bin/pg_dump/pg_dump.c                       |   4 +
src/bin/psql/describe.c                         |   8 +-
src/bin/psql/tab-complete.c                     |   5 +-
src/include/catalog/catversion.h                |   2 +-
src/include/catalog/pg_subscription.h           |   5 +
src/include/nodes/parsenodes.h                  |   3 +-
src/test/regress/expected/subscription.out      | 126 +++++++------
src/test/regress/sql/subscription.sql           |  11 ++
src/test/subscription/t/029_disable_on_error.pl |  94 ----------
src/test/subscription/t/029_on_error.pl         | 183 +++++++++++++++++++
18 files changed, 665 insertions(+), 173 deletions(-)