Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions
Amit Kapila <amit.kapila16@gmail.com>
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API reference →
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Tighten the concurrent abort check during decoding.
- 2ce353fc1902 14.0 landed
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Improve hash_create()'s API for some added robustness.
- b3817f5f7746 14.0 landed
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Use HASH_BLOBS for xidhash.
- a1b8aa1e4eec 14.0 landed
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Fix initialization of RelationSyncEntry for streaming transactions.
- 69bd60672af6 14.0 landed
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Remove unused function declaration in logicalproto.h.
- ddd5f6d2609b 14.0 landed
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Add additional tests to test streaming of in-progress transactions.
- 58b5ae9d62bd 14.0 landed
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Fix inline marking introduced in commit 464824323e.
- ac15b499f7f9 14.0 landed
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Add support for streaming to built-in logical replication.
- 464824323e57 14.0 landed
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Fix the SharedFileSetUnregister API.
- 4ab77697f67a 14.0 landed
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Fix comment in procarray.c
- 77c7267c37f7 14.0 cited
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Suppress compiler warning in non-cassert builds.
- e942af7b8261 14.0 cited
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Extend the BufFile interface.
- 808e13b282ef 14.0 landed
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Mark a few logical decoding related variables with PGDLLIMPORT.
- b48cac3b10a0 14.0 landed
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Implement streaming mode in ReorderBuffer.
- 7259736a6e5b 14.0 landed
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Extend the logical decoding output plugin API with stream methods.
- 45fdc9738b36 14.0 landed
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WAL Log invalidations at command end with wal_level=logical.
- c55040ccd017 14.0 landed
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Immediately WAL-log subtransaction and top-level XID association.
- 0bead9af484c 14.0 landed
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Allow logical replication to transfer data in binary format.
- 9de77b545313 14.0 cited
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Only superuser can set sslcert/sslkey in postgres_fdw user mappings
- cebf9d6e6ee1 13.0 cited
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Track statistics for spilling of changes from ReorderBuffer.
- 9290ad198b15 13.0 landed
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Add logical_decoding_work_mem to limit ReorderBuffer memory usage.
- cec2edfa7859 13.0 landed
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logical decoding: process ASSIGNMENT during snapshot build
- bac2fae05c77 13.0 cited
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Emit invalidations to standby for transactions without xid.
- c6ff84b06a68 9.6.0 cited
On Sun, Sep 29, 2019 at 11:24 AM Amit Kapila <amit.kapila16@gmail.com>
wrote:
> On Sun, Sep 29, 2019 at 12:39 AM Tomas Vondra
> <tomas.vondra@2ndquadrant.com> wrote:
> >
>
> Yeah, it is better to deal it separately as I am also not entirely
> convinced at this stage about this parameter. I have mentioned the
> same in the previous email as well.
>
> While glancing through the changes, I noticed a small thing:
> +#logical_decoding_work_mem = 64MB # min 1MB, or -1 to use
maintenance_work_mem
>
> I guess this need to be updated.
>
On further testing, I found that the patch seems to have problems with
toast. Consider below scenario:
Session-1
Create table large_text(t1 text);
INSERT INTO large_text
SELECT (SELECT string_agg('x', ',')
FROM generate_series(1, 1000000)) FROM generate_series(1, 1000);
Session-2
SELECT * FROM pg_create_logical_replication_slot('regression_slot',
'test_decoding');
SELECT * FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL);
*--kaboom*
The second statement in Session-2 leads to a crash.
Other than that, I am not sure if the changes related to spill to disk
after logical_decoding_work_mem works for toast table as I couldn't hit
that code for toast table case, but I might be missing something. As
mentioned previously, I feel there should be some way to test whether this
patch works for the cases it claims to work. As of now, I have to check
via debugging. Let me know if there is any way, I can test this.
I am reluctant to say, but I think this patch still needs some more work
(review, test, rework) before we can commit it.
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com