Horton

Re: Minimal logical decoding on standbys

Rahila Syed <rahila.syed@2ndquadrant.com>

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From: Rahila Syed <rahila.syed@2ndquadrant.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2019-12-12T09:57:53Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

Hi Amit,

Please see following comments:

1.  0002-Add-info-in-WAL-records-in-preparation-for-logical-s.patch

--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -17,6 +17,7 @@

 #include "access/hash.h"
 #include "access/hash_xlog.h"
+#include "catalog/catalog.h"
 #include "miscadmin.h"

The above header inclusion is not necessary as the code compiles fine
without it.
Also, this patch does not apply cleanly on latest master due to the above
line.

2.  Following test fails with error.
make -C src/test/recovery/ check PROVE_TESTS=t/
018_standby_logical_decoding_xmins.pl
#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 120.
#          got: ''
#     expected: anything else

#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 141.
#          got: ''
#     expected: anything else

#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 159.
#          got: ''
#     expected: anything else
t/018_standby_logical_decoding_xmins.pl .. 20/27 # poll_query_until timed
out executing this query:
#

Physical catalog_xmin is NULL on master after logical slot creation on
standby .

Due to this below command in the test fails with syntax error as it
constructs the SQL query using catalog_xmin value
obtained above:

# SELECT catalog_xmin::varchar::int >
# FROM pg_catalog.pg_replication_slots
# WHERE slot_name = 'master_physical';
#
# expecting this output:
# t
# last actual query output:
#
# with stderr:
# ERROR:  syntax error at or near "FROM"
# LINE 3:   FROM pg_catalog.pg_replication_slots

Thank you,
-- 
Rahila Syed
Performance Engineer
2ndQuadrant
http://www.2ndQuadrant.com <http://www.2ndquadrant.com/>
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