Re: row filtering for logical replication

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>

To: "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>

Cc: Amit Kapila <amit.kapila16@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Greg Nancarrow <gregn4422@gmail.com>, Euler Taveira <euler@eulerto.com>, Peter Smith <smithpb2250@gmail.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Önder Kalacı <onderkalaci@gmail.com>, japin <japinli@hotmail.com>, Michael Paquier <michael@paquier.xyz>, David Steele <david@pgmasters.net>, Craig Ringer <craig@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Rahila Syed <rahilasyed90@gmail.com>

Date: 2021-07-27T04:26:33Z

Lists: pgsql-hackers

Commits

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Release cache tuple when no longer needed
- ed0fbc8e5ac9 15.0 landed
Add some additional tests for row filters in logical replication.
- ceb57afd3ce1 15.0 landed
Fix one of the tests introduced in commit 52e4f0cd47.
- cfb4e209ec15 15.0 landed
Allow specifying row filters for logical replication of tables.
- 52e4f0cd472d 15.0 landed
Move scanint8() to numutils.c
- cfc7191dfea3 15.0 cited
Replace Test::More plans with done_testing
- 549ec201d613 15.0 cited
Reduce relcache access in WAL sender streaming logical changes
- 6ce16088bfed 15.0 cited
Small cleanups related to PUBLICATION framework code
- c9105dd3660f 15.0 cited
Add a view to show the stats of subscription workers.
- 8d74fc96db5f 15.0 cited
Allow publishing the tables of schema.
- 5a2832465fd8 15.0 cited
Doc: improve documentation of CREATE/ALTER SUBSCRIPTION.
- 1882d6cca161 15.0 cited
Add PublicationTable and PublicationRelInfo structs
- 0c6828fa987b 15.0 cited
Remove unused argument "txn" in maybe_send_schema().
- 93d573d86571 15.0 cited
Add prepare API support for streaming transactions in logical replication.
- 63cf61cdeb7b 15.0 cited
Unify PostgresNode's new() and get_new_node() methods
- 201a76183e20 15.0 cited
Use l*_node() family of functions where appropriate
- 2b00db4fb0c7 15.0 cited
Add support for prepared transactions to built-in logical replication.
- a8fd13cab0ba 15.0 cited
Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.
- ef9480509622 11.13 cited
Rename a parse node to be more general
- 91d1f2d30210 14.0 landed
Remove unused column atttypmod from initial tablesync query
- 4ad31bb2ef25 14.0 landed
SEARCH and CYCLE clauses
- 3696a600e229 14.0 cited

On Tue, Jul 27, 2021 at 6:21 AM houzj.fnst@fujitsu.com
<houzj.fnst@fujitsu.com> wrote:

> 1) UPDATE a nonkey column in publisher.
> 2) Use debugger to block the walsender process in function
>    pgoutput_row_filter_exec_expr().
> 3) Open another psql to connect the publisher, and drop the table which updated
>    in 1).
> 4) Unblock the debugger in 2), and then I can see the following error:
> ---
> ERROR:  could not read block 0 in file "base/13675/16391"

Yeah, that's a big problem, seems like the expression evaluation
machinery directly going and detoasting the externally stored data
using some random snapshot.  Ideally, in walsender we can never
attempt to detoast the data because there is no guarantee that those
data are preserved.  Somehow before going to the expression evaluation
machinery, I think we will have to deform that tuple and need to do
something for the externally stored data otherwise it will be very
difficult to control that inside the expression evaluation.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com