pgsql: logical decoding: Tell reorderbuffer about all xids. - Mailing list pgsql-committers

From Andres Freund
Subject pgsql: logical decoding: Tell reorderbuffer about all xids.
Date
Msg-id E1acOFW-0001Z7-0b@gemulon.postgresql.org
Whole thread Raw
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logical decoding: Tell reorderbuffer about all xids.

Logical decoding's reorderbuffer keeps transactions in an LSN ordered
list for efficiency. To make that's efficiently possible upper-level
xids are forced to be logged before nested subtransaction xids.  That
only works though if these records are all looked at: Unfortunately we
didn't do so for e.g. row level locks, which are otherwise uninteresting
for logical decoding.

This could lead to errors like:
"ERROR: subxact logged without previous toplevel record".

It's not sufficient to just look at row locking records, the xid could
appear first due to a lot of other types of records (which will trigger
the transaction to be marked logged with MarkCurrentTransactionIdLoggedIfAny).
So invent infrastructure to tell reorderbuffer about xids seen, when
they'd otherwise not pass through reorderbuffer.c.

Reported-By: Jarred Ward
Bug: #13844
Discussion: 20160105033249.1087.66040@wrigleys.postgresql.org
Backpatch: 9.4, where logical decoding was added

Branch
------
REL9_5_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/6e759cefe809cb7852cdf6ea3088d8604a817185

Modified Files
--------------
contrib/test_decoding/Makefile                  |  4 +--
contrib/test_decoding/expected/xact.out         | 42 +++++++++++++++++++++++++
contrib/test_decoding/sql/xact.sql              | 22 +++++++++++++
src/backend/replication/logical/decode.c        | 28 ++++++++++++++++-
src/backend/replication/logical/reorderbuffer.c | 21 ++++++++-----
src/backend/replication/logical/snapbuild.c     |  6 +---
src/include/replication/reorderbuffer.h         |  2 +-
7 files changed, 108 insertions(+), 17 deletions(-)


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