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Add contrib/pg_logicalinspect.
This module provides SQL functions that allow to inspect logical decoding components. It currently allows to inspect the contents of serialized logical snapshots of a running database cluster, which is useful for debugging or educational purposes. Author: Bertrand Drouvot Reviewed-by: Amit Kapila, Shveta Malik, Peter Smith, Peter Eisentraut Reviewed-by: David G. Johnston Discussion: https://postgr.es/m/ZscuZ92uGh3wm4tW%40ip-10-97-1-34.eu-west-3.compute.internal
This commit is contained in:
Masahiko Sawada
@ -32,6 +32,7 @@ SUBDIRS = \
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passwordcheck \
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pg_buffercache \
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pg_freespacemap \
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pg_logicalinspect \
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pg_prewarm \
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pg_stat_statements \
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pg_surgery \
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@ -46,6 +46,7 @@ subdir('passwordcheck')
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subdir('pg_buffercache')
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subdir('pgcrypto')
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subdir('pg_freespacemap')
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subdir('pg_logicalinspect')
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subdir('pg_prewarm')
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subdir('pgrowlocks')
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subdir('pg_stat_statements')
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6
contrib/pg_logicalinspect/.gitignore
vendored
Normal file
6
contrib/pg_logicalinspect/.gitignore
vendored
Normal file
@ -0,0 +1,6 @@
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# Generated subdirectories
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/log/
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/results/
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/output_iso/
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/tmp_check/
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/tmp_check_iso/
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31
contrib/pg_logicalinspect/Makefile
Normal file
31
contrib/pg_logicalinspect/Makefile
Normal file
@ -0,0 +1,31 @@
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# contrib/pg_logicalinspect/Makefile
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MODULE_big = pg_logicalinspect
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OBJS = \
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$(WIN32RES) \
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pg_logicalinspect.o
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PGFILEDESC = "pg_logicalinspect - functions to inspect logical decoding components"
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EXTENSION = pg_logicalinspect
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DATA = pg_logicalinspect--1.0.sql
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EXTRA_INSTALL = contrib/test_decoding
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ISOLATION = logical_inspect
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ISOLATION_OPTS = --temp-config $(top_srcdir)/contrib/pg_logicalinspect/logicalinspect.conf
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# Disabled because these tests require "wal_level=logical", which
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# some installcheck users do not have (e.g. buildfarm clients).
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NO_INSTALLCHECK = 1
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ifdef USE_PGXS
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PG_CONFIG = pg_config
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PGXS := $(shell $(PG_CONFIG) --pgxs)
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include $(PGXS)
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else
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subdir = contrib/pg_logicalinspect
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top_builddir = ../..
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include $(top_builddir)/src/Makefile.global
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include $(top_srcdir)/contrib/contrib-global.mk
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endif
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52
contrib/pg_logicalinspect/expected/logical_inspect.out
Normal file
52
contrib/pg_logicalinspect/expected/logical_inspect.out
Normal file
@ -0,0 +1,52 @@
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Parsed test spec with 2 sessions
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starting permutation: s0_init s0_begin s0_savepoint s0_truncate s1_checkpoint s1_get_changes s0_commit s0_begin s0_insert s1_checkpoint s1_get_changes s0_commit s1_get_changes s1_get_logical_snapshot_info s1_get_logical_snapshot_meta
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step s0_init: SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding');
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?column?
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--------
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init
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(1 row)
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step s0_begin: BEGIN;
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step s0_savepoint: SAVEPOINT sp1;
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step s0_truncate: TRUNCATE tbl1;
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step s1_checkpoint: CHECKPOINT;
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step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
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data
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----
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(0 rows)
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step s0_commit: COMMIT;
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step s0_begin: BEGIN;
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step s0_insert: INSERT INTO tbl1 VALUES (1);
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step s1_checkpoint: CHECKPOINT;
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step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
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data
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---------------------------------------
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BEGIN
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table public.tbl1: TRUNCATE: (no-flags)
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COMMIT
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(3 rows)
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step s0_commit: COMMIT;
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step s1_get_changes: SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0');
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data
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-------------------------------------------------------------
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BEGIN
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table public.tbl1: INSERT: val1[integer]:1 val2[integer]:null
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COMMIT
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(3 rows)
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step s1_get_logical_snapshot_info: SELECT info.state, info.catchange_count, array_length(info.catchange_xip,1) AS catchange_array_length, info.committed_count, array_length(info.committed_xip,1) AS committed_array_length FROM pg_ls_logicalsnapdir(), pg_get_logical_snapshot_info(name) AS info ORDER BY 2;
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state |catchange_count|catchange_array_length|committed_count|committed_array_length
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----------+---------------+----------------------+---------------+----------------------
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consistent| 0| | 2| 2
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consistent| 2| 2| 0|
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(2 rows)
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step s1_get_logical_snapshot_meta: SELECT COUNT(meta.*) from pg_ls_logicalsnapdir(), pg_get_logical_snapshot_meta(name) as meta;
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count
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-----
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2
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(1 row)
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1
contrib/pg_logicalinspect/logicalinspect.conf
Normal file
1
contrib/pg_logicalinspect/logicalinspect.conf
Normal file
@ -0,0 +1 @@
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wal_level = logical
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39
contrib/pg_logicalinspect/meson.build
Normal file
39
contrib/pg_logicalinspect/meson.build
Normal file
@ -0,0 +1,39 @@
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# Copyright (c) 2024, PostgreSQL Global Development Group
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pg_logicalinspect_sources = files('pg_logicalinspect.c')
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if host_system == 'windows'
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pg_logicalinspect_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
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'--NAME', 'pg_logicalinspect',
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'--FILEDESC', 'pg_logicalinspect - functions to inspect logical decoding components',])
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endif
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pg_logicalinspect = shared_module('pg_logicalinspect',
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pg_logicalinspect_sources,
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kwargs: contrib_mod_args + {
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'dependencies': contrib_mod_args['dependencies'],
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},
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)
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contrib_targets += pg_logicalinspect
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install_data(
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'pg_logicalinspect.control',
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'pg_logicalinspect--1.0.sql',
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kwargs: contrib_data_args,
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)
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tests += {
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'name': 'pg_logicalinspect',
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'sd': meson.current_source_dir(),
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'bd': meson.current_build_dir(),
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'isolation': {
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'specs': [
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'logical_inspect',
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],
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'regress_args': [
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'--temp-config', files('logicalinspect.conf'),
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],
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# see above
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'runningcheck': false,
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},
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}
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43
contrib/pg_logicalinspect/pg_logicalinspect--1.0.sql
Normal file
43
contrib/pg_logicalinspect/pg_logicalinspect--1.0.sql
Normal file
@ -0,0 +1,43 @@
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/* contrib/pg_logicalinspect/pg_logicalinspect--1.0.sql */
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-- complain if script is sourced in psql, rather than via CREATE EXTENSION
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\echo Use "CREATE EXTENSION pg_logicalinspect" to load this file. \quit
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--
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-- pg_get_logical_snapshot_meta()
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--
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CREATE FUNCTION pg_get_logical_snapshot_meta(IN filename text,
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OUT magic int4,
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OUT checksum int8,
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OUT version int4
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)
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AS 'MODULE_PATHNAME', 'pg_get_logical_snapshot_meta'
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LANGUAGE C STRICT PARALLEL SAFE;
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REVOKE EXECUTE ON FUNCTION pg_get_logical_snapshot_meta(text) FROM PUBLIC;
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GRANT EXECUTE ON FUNCTION pg_get_logical_snapshot_meta(text) TO pg_read_server_files;
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--
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-- pg_get_logical_snapshot_info()
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--
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CREATE FUNCTION pg_get_logical_snapshot_info(IN filename text,
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OUT state text,
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OUT xmin xid,
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OUT xmax xid,
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OUT start_decoding_at pg_lsn,
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OUT two_phase_at pg_lsn,
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OUT initial_xmin_horizon xid,
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OUT building_full_snapshot boolean,
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OUT in_slot_creation boolean,
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OUT last_serialized_snapshot pg_lsn,
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OUT next_phase_at xid,
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OUT committed_count int4,
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OUT committed_xip xid[],
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OUT catchange_count int4,
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OUT catchange_xip xid[]
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)
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AS 'MODULE_PATHNAME', 'pg_get_logical_snapshot_info'
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LANGUAGE C STRICT PARALLEL SAFE;
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REVOKE EXECUTE ON FUNCTION pg_get_logical_snapshot_info(text) FROM PUBLIC;
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GRANT EXECUTE ON FUNCTION pg_get_logical_snapshot_info(text) TO pg_read_server_files;
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167
contrib/pg_logicalinspect/pg_logicalinspect.c
Normal file
167
contrib/pg_logicalinspect/pg_logicalinspect.c
Normal file
@ -0,0 +1,167 @@
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/*-------------------------------------------------------------------------
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*
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* pg_logicalinspect.c
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* Functions to inspect contents of PostgreSQL logical snapshots
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*
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* Copyright (c) 2024, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* contrib/pg_logicalinspect/pg_logicalinspect.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "funcapi.h"
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#include "replication/snapbuild_internal.h"
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#include "utils/array.h"
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#include "utils/builtins.h"
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#include "utils/pg_lsn.h"
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PG_MODULE_MAGIC;
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PG_FUNCTION_INFO_V1(pg_get_logical_snapshot_meta);
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PG_FUNCTION_INFO_V1(pg_get_logical_snapshot_info);
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/* Return the description of SnapBuildState */
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static const char *
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get_snapbuild_state_desc(SnapBuildState state)
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{
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const char *stateDesc = "unknown state";
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switch (state)
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{
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case SNAPBUILD_START:
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stateDesc = "start";
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break;
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case SNAPBUILD_BUILDING_SNAPSHOT:
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stateDesc = "building";
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break;
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case SNAPBUILD_FULL_SNAPSHOT:
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stateDesc = "full";
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break;
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case SNAPBUILD_CONSISTENT:
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stateDesc = "consistent";
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break;
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}
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return stateDesc;
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}
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/*
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* Retrieve the logical snapshot file metadata.
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*/
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Datum
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pg_get_logical_snapshot_meta(PG_FUNCTION_ARGS)
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{
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#define PG_GET_LOGICAL_SNAPSHOT_META_COLS 3
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SnapBuildOnDisk ondisk;
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HeapTuple tuple;
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Datum values[PG_GET_LOGICAL_SNAPSHOT_META_COLS] = {0};
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bool nulls[PG_GET_LOGICAL_SNAPSHOT_META_COLS] = {0};
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TupleDesc tupdesc;
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char path[MAXPGPATH];
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int i = 0;
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text *filename_t = PG_GETARG_TEXT_PP(0);
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/* Build a tuple descriptor for our result type */
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if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
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elog(ERROR, "return type must be a row type");
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sprintf(path, "%s/%s",
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PG_LOGICAL_SNAPSHOTS_DIR,
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text_to_cstring(filename_t));
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/* Validate and restore the snapshot to 'ondisk' */
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SnapBuildRestoreSnapshot(&ondisk, path, CurrentMemoryContext, false);
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values[i++] = UInt32GetDatum(ondisk.magic);
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values[i++] = Int64GetDatum((int64) ondisk.checksum);
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values[i++] = UInt32GetDatum(ondisk.version);
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Assert(i == PG_GET_LOGICAL_SNAPSHOT_META_COLS);
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tuple = heap_form_tuple(tupdesc, values, nulls);
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PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
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#undef PG_GET_LOGICAL_SNAPSHOT_META_COLS
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}
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Datum
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pg_get_logical_snapshot_info(PG_FUNCTION_ARGS)
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{
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#define PG_GET_LOGICAL_SNAPSHOT_INFO_COLS 14
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SnapBuildOnDisk ondisk;
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HeapTuple tuple;
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Datum values[PG_GET_LOGICAL_SNAPSHOT_INFO_COLS] = {0};
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bool nulls[PG_GET_LOGICAL_SNAPSHOT_INFO_COLS] = {0};
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TupleDesc tupdesc;
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char path[MAXPGPATH];
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int i = 0;
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text *filename_t = PG_GETARG_TEXT_PP(0);
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/* Build a tuple descriptor for our result type */
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if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
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elog(ERROR, "return type must be a row type");
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sprintf(path, "%s/%s",
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PG_LOGICAL_SNAPSHOTS_DIR,
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text_to_cstring(filename_t));
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/* Validate and restore the snapshot to 'ondisk' */
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SnapBuildRestoreSnapshot(&ondisk, path, CurrentMemoryContext, false);
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values[i++] = CStringGetTextDatum(get_snapbuild_state_desc(ondisk.builder.state));
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values[i++] = TransactionIdGetDatum(ondisk.builder.xmin);
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values[i++] = TransactionIdGetDatum(ondisk.builder.xmax);
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values[i++] = LSNGetDatum(ondisk.builder.start_decoding_at);
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values[i++] = LSNGetDatum(ondisk.builder.two_phase_at);
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values[i++] = TransactionIdGetDatum(ondisk.builder.initial_xmin_horizon);
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values[i++] = BoolGetDatum(ondisk.builder.building_full_snapshot);
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values[i++] = BoolGetDatum(ondisk.builder.in_slot_creation);
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values[i++] = LSNGetDatum(ondisk.builder.last_serialized_snapshot);
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values[i++] = TransactionIdGetDatum(ondisk.builder.next_phase_at);
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values[i++] = UInt32GetDatum(ondisk.builder.committed.xcnt);
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if (ondisk.builder.committed.xcnt > 0)
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{
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Datum *arrayelems;
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arrayelems = (Datum *) palloc(ondisk.builder.committed.xcnt * sizeof(Datum));
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for (int j = 0; j < ondisk.builder.committed.xcnt; j++)
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arrayelems[j] = TransactionIdGetDatum(ondisk.builder.committed.xip[j]);
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values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,
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ondisk.builder.committed.xcnt,
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XIDOID));
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}
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else
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nulls[i++] = true;
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values[i++] = UInt32GetDatum(ondisk.builder.catchange.xcnt);
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if (ondisk.builder.catchange.xcnt > 0)
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{
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Datum *arrayelems;
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arrayelems = (Datum *) palloc(ondisk.builder.catchange.xcnt * sizeof(Datum));
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for (int j = 0; j < ondisk.builder.catchange.xcnt; j++)
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arrayelems[j] = TransactionIdGetDatum(ondisk.builder.catchange.xip[j]);
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values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,
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ondisk.builder.catchange.xcnt,
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XIDOID));
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}
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else
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nulls[i++] = true;
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Assert(i == PG_GET_LOGICAL_SNAPSHOT_INFO_COLS);
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tuple = heap_form_tuple(tupdesc, values, nulls);
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PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
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#undef PG_GET_LOGICAL_SNAPSHOT_INFO_COLS
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}
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5
contrib/pg_logicalinspect/pg_logicalinspect.control
Normal file
5
contrib/pg_logicalinspect/pg_logicalinspect.control
Normal file
@ -0,0 +1,5 @@
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# pg_logicalinspect extension
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comment = 'functions to inspect logical decoding components'
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default_version = '1.0'
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module_pathname = '$libdir/pg_logicalinspect'
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relocatable = true
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34
contrib/pg_logicalinspect/specs/logical_inspect.spec
Normal file
34
contrib/pg_logicalinspect/specs/logical_inspect.spec
Normal file
@ -0,0 +1,34 @@
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# Test the pg_logicalinspect functions: that needs some permutation to
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# ensure that we are creating multiple logical snapshots and that one of them
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# contains ongoing catalogs changes.
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setup
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{
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DROP TABLE IF EXISTS tbl1;
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CREATE TABLE tbl1 (val1 integer, val2 integer);
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CREATE EXTENSION pg_logicalinspect;
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}
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teardown
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||||
{
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DROP TABLE tbl1;
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||||
SELECT 'stop' FROM pg_drop_replication_slot('isolation_slot');
|
||||
DROP EXTENSION pg_logicalinspect;
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}
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||||
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session "s0"
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setup { SET synchronous_commit=on; }
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step "s0_init" { SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding'); }
|
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step "s0_begin" { BEGIN; }
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step "s0_savepoint" { SAVEPOINT sp1; }
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step "s0_truncate" { TRUNCATE tbl1; }
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step "s0_insert" { INSERT INTO tbl1 VALUES (1); }
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step "s0_commit" { COMMIT; }
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session "s1"
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setup { SET synchronous_commit=on; }
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step "s1_checkpoint" { CHECKPOINT; }
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step "s1_get_changes" { SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0'); }
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||||
step "s1_get_logical_snapshot_meta" { SELECT COUNT(meta.*) from pg_ls_logicalsnapdir(), pg_get_logical_snapshot_meta(name) as meta;}
|
||||
step "s1_get_logical_snapshot_info" { SELECT info.state, info.catchange_count, array_length(info.catchange_xip,1) AS catchange_array_length, info.committed_count, array_length(info.committed_xip,1) AS committed_array_length FROM pg_ls_logicalsnapdir(), pg_get_logical_snapshot_info(name) AS info ORDER BY 2; }
|
||||
|
||||
permutation "s0_init" "s0_begin" "s0_savepoint" "s0_truncate" "s1_checkpoint" "s1_get_changes" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes" "s1_get_logical_snapshot_info" "s1_get_logical_snapshot_meta"
|
||||
@ -154,6 +154,7 @@ CREATE EXTENSION <replaceable>extension_name</replaceable>;
|
||||
&pgbuffercache;
|
||||
&pgcrypto;
|
||||
&pgfreespacemap;
|
||||
&pglogicalinspect;
|
||||
&pgprewarm;
|
||||
&pgrowlocks;
|
||||
&pgstatstatements;
|
||||
|
||||
@ -143,6 +143,7 @@
|
||||
<!ENTITY pgbuffercache SYSTEM "pgbuffercache.sgml">
|
||||
<!ENTITY pgcrypto SYSTEM "pgcrypto.sgml">
|
||||
<!ENTITY pgfreespacemap SYSTEM "pgfreespacemap.sgml">
|
||||
<!ENTITY pglogicalinspect SYSTEM "pglogicalinspect.sgml">
|
||||
<!ENTITY pgprewarm SYSTEM "pgprewarm.sgml">
|
||||
<!ENTITY pgrowlocks SYSTEM "pgrowlocks.sgml">
|
||||
<!ENTITY pgstatstatements SYSTEM "pgstatstatements.sgml">
|
||||
|
||||
143
doc/src/sgml/pglogicalinspect.sgml
Normal file
143
doc/src/sgml/pglogicalinspect.sgml
Normal file
@ -0,0 +1,143 @@
|
||||
<!-- doc/src/sgml/pglogicalinspect.sgml -->
|
||||
|
||||
<sect1 id="pglogicalinspect" xreflabel="pg_logicalinspect">
|
||||
<title>pg_logicalinspect — logical decoding components inspection</title>
|
||||
|
||||
<indexterm zone="pglogicalinspect">
|
||||
<primary>pg_logicalinspect</primary>
|
||||
</indexterm>
|
||||
|
||||
<para>
|
||||
The <filename>pg_logicalinspect</filename> module provides SQL functions
|
||||
that allow you to inspect the contents of logical decoding components. It
|
||||
allows the inspection of serialized logical snapshots of a running
|
||||
<productname>PostgreSQL</productname> database cluster, which is useful
|
||||
for debugging or educational purposes.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
By default, use of these functions is restricted to superusers and members of
|
||||
the <literal>pg_read_server_files</literal> role. Access may be granted by
|
||||
superusers to others using <command>GRANT</command>.
|
||||
</para>
|
||||
|
||||
<sect2 id="pglogicalinspect-funcs">
|
||||
<title>Functions</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry id="pglogicalinspect-funcs-pg-get-logical-snapshot-meta">
|
||||
<term>
|
||||
<function>pg_get_logical_snapshot_meta(filename text) returns record</function>
|
||||
</term>
|
||||
|
||||
<listitem>
|
||||
<para>
|
||||
Gets logical snapshot metadata about a snapshot file that is located in
|
||||
the server's <filename>pg_logical/snapshots</filename> directory.
|
||||
The <replaceable>filename</replaceable> argument represents the snapshot
|
||||
file name.
|
||||
For example:
|
||||
<screen>
|
||||
postgres=# SELECT * FROM pg_ls_logicalsnapdir();
|
||||
-[ RECORD 1 ]+-----------------------
|
||||
name | 0-40796E18.snap
|
||||
size | 152
|
||||
modification | 2024-08-14 16:36:32+00
|
||||
|
||||
postgres=# SELECT * FROM pg_get_logical_snapshot_meta('0-40796E18.snap');
|
||||
-[ RECORD 1 ]--------
|
||||
magic | 1369563137
|
||||
checksum | 1028045905
|
||||
version | 6
|
||||
|
||||
postgres=# SELECT ss.name, meta.* FROM pg_ls_logicalsnapdir() AS ss,
|
||||
pg_get_logical_snapshot_meta(ss.name) AS meta;
|
||||
-[ RECORD 1 ]-------------
|
||||
name | 0-40796E18.snap
|
||||
magic | 1369563137
|
||||
checksum | 1028045905
|
||||
version | 6
|
||||
</screen>
|
||||
</para>
|
||||
<para>
|
||||
If <replaceable>filename</replaceable> does not match a snapshot file, the
|
||||
function raises an error.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry id="pglogicalinspect-funcs-pg-get-logical-snapshot-info">
|
||||
<term>
|
||||
<function>pg_get_logical_snapshot_info(filename text) returns record</function>
|
||||
</term>
|
||||
|
||||
<listitem>
|
||||
<para>
|
||||
Gets logical snapshot information about a snapshot file that is located in
|
||||
the server's <filename>pg_logical/snapshots</filename> directory.
|
||||
The <replaceable>filename</replaceable> argument represents the snapshot
|
||||
file name.
|
||||
For example:
|
||||
<screen>
|
||||
postgres=# SELECT * FROM pg_ls_logicalsnapdir();
|
||||
-[ RECORD 1 ]+-----------------------
|
||||
name | 0-40796E18.snap
|
||||
size | 152
|
||||
modification | 2024-08-14 16:36:32+00
|
||||
|
||||
postgres=# SELECT * FROM pg_get_logical_snapshot_info('0-40796E18.snap');
|
||||
-[ RECORD 1 ]------------+-----------
|
||||
state | consistent
|
||||
xmin | 751
|
||||
xmax | 751
|
||||
start_decoding_at | 0/40796AF8
|
||||
two_phase_at | 0/40796AF8
|
||||
initial_xmin_horizon | 0
|
||||
building_full_snapshot | f
|
||||
in_slot_creation | f
|
||||
last_serialized_snapshot | 0/0
|
||||
next_phase_at | 0
|
||||
committed_count | 0
|
||||
committed_xip |
|
||||
catchange_count | 2
|
||||
catchange_xip | {751,752}
|
||||
|
||||
postgres=# SELECT ss.name, info.* FROM pg_ls_logicalsnapdir() AS ss,
|
||||
pg_get_logical_snapshot_info(ss.name) AS info;
|
||||
-[ RECORD 1 ]------------+----------------
|
||||
name | 0-40796E18.snap
|
||||
state | consistent
|
||||
xmin | 751
|
||||
xmax | 751
|
||||
start_decoding_at | 0/40796AF8
|
||||
two_phase_at | 0/40796AF8
|
||||
initial_xmin_horizon | 0
|
||||
building_full_snapshot | f
|
||||
in_slot_creation | f
|
||||
last_serialized_snapshot | 0/0
|
||||
next_phase_at | 0
|
||||
committed_count | 0
|
||||
committed_xip |
|
||||
catchange_count | 2
|
||||
catchange_xip | {751,752}
|
||||
</screen>
|
||||
</para>
|
||||
<para>
|
||||
If <replaceable>filename</replaceable> does not match a snapshot file, the
|
||||
function raises an error.
|
||||
</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
</variablelist>
|
||||
</sect2>
|
||||
|
||||
<sect2 id="pglogicalinspect-author">
|
||||
<title>Author</title>
|
||||
|
||||
<para>
|
||||
Bertrand Drouvot <email>bertranddrouvot.pg@gmail.com</email>
|
||||
</para>
|
||||
</sect2>
|
||||
|
||||
</sect1>
|
||||
@ -1684,34 +1684,31 @@ out:
|
||||
}
|
||||
|
||||
/*
|
||||
* Restore a snapshot into 'builder' if previously one has been stored at the
|
||||
* location indicated by 'lsn'. Returns true if successful, false otherwise.
|
||||
* Restore the logical snapshot file contents to 'ondisk'.
|
||||
*
|
||||
* 'context' is the memory context where the catalog modifying/committed xid
|
||||
* will live.
|
||||
* If 'missing_ok' is true, will not throw an error if the file is not found.
|
||||
*/
|
||||
static bool
|
||||
SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
|
||||
bool
|
||||
SnapBuildRestoreSnapshot(SnapBuildOnDisk *ondisk, const char *path,
|
||||
MemoryContext context, bool missing_ok)
|
||||
{
|
||||
SnapBuildOnDisk ondisk;
|
||||
int fd;
|
||||
char path[MAXPGPATH];
|
||||
Size sz;
|
||||
pg_crc32c checksum;
|
||||
|
||||
/* no point in loading a snapshot if we're already there */
|
||||
if (builder->state == SNAPBUILD_CONSISTENT)
|
||||
return false;
|
||||
|
||||
sprintf(path, "%s/%X-%X.snap",
|
||||
PG_LOGICAL_SNAPSHOTS_DIR,
|
||||
LSN_FORMAT_ARGS(lsn));
|
||||
Size sz;
|
||||
|
||||
fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
|
||||
|
||||
if (fd < 0 && errno == ENOENT)
|
||||
if (fd < 0)
|
||||
{
|
||||
if (missing_ok && errno == ENOENT)
|
||||
return false;
|
||||
else if (fd < 0)
|
||||
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not open file \"%s\": %m", path)));
|
||||
}
|
||||
|
||||
/* ----
|
||||
* Make sure the snapshot had been stored safely to disk, that's normally
|
||||
@ -1724,47 +1721,46 @@ SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
|
||||
fsync_fname(path, false);
|
||||
fsync_fname(PG_LOGICAL_SNAPSHOTS_DIR, true);
|
||||
|
||||
|
||||
/* read statically sized portion of snapshot */
|
||||
SnapBuildRestoreContents(fd, (char *) &ondisk, SnapBuildOnDiskConstantSize, path);
|
||||
SnapBuildRestoreContents(fd, (char *) ondisk, SnapBuildOnDiskConstantSize, path);
|
||||
|
||||
if (ondisk.magic != SNAPBUILD_MAGIC)
|
||||
if (ondisk->magic != SNAPBUILD_MAGIC)
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_DATA_CORRUPTED),
|
||||
errmsg("snapbuild state file \"%s\" has wrong magic number: %u instead of %u",
|
||||
path, ondisk.magic, SNAPBUILD_MAGIC)));
|
||||
path, ondisk->magic, SNAPBUILD_MAGIC)));
|
||||
|
||||
if (ondisk.version != SNAPBUILD_VERSION)
|
||||
if (ondisk->version != SNAPBUILD_VERSION)
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_DATA_CORRUPTED),
|
||||
errmsg("snapbuild state file \"%s\" has unsupported version: %u instead of %u",
|
||||
path, ondisk.version, SNAPBUILD_VERSION)));
|
||||
path, ondisk->version, SNAPBUILD_VERSION)));
|
||||
|
||||
INIT_CRC32C(checksum);
|
||||
COMP_CRC32C(checksum,
|
||||
((char *) &ondisk) + SnapBuildOnDiskNotChecksummedSize,
|
||||
((char *) ondisk) + SnapBuildOnDiskNotChecksummedSize,
|
||||
SnapBuildOnDiskConstantSize - SnapBuildOnDiskNotChecksummedSize);
|
||||
|
||||
/* read SnapBuild */
|
||||
SnapBuildRestoreContents(fd, (char *) &ondisk.builder, sizeof(SnapBuild), path);
|
||||
COMP_CRC32C(checksum, &ondisk.builder, sizeof(SnapBuild));
|
||||
SnapBuildRestoreContents(fd, (char *) &ondisk->builder, sizeof(SnapBuild), path);
|
||||
COMP_CRC32C(checksum, &ondisk->builder, sizeof(SnapBuild));
|
||||
|
||||
/* restore committed xacts information */
|
||||
if (ondisk.builder.committed.xcnt > 0)
|
||||
if (ondisk->builder.committed.xcnt > 0)
|
||||
{
|
||||
sz = sizeof(TransactionId) * ondisk.builder.committed.xcnt;
|
||||
ondisk.builder.committed.xip = MemoryContextAllocZero(builder->context, sz);
|
||||
SnapBuildRestoreContents(fd, (char *) ondisk.builder.committed.xip, sz, path);
|
||||
COMP_CRC32C(checksum, ondisk.builder.committed.xip, sz);
|
||||
sz = sizeof(TransactionId) * ondisk->builder.committed.xcnt;
|
||||
ondisk->builder.committed.xip = MemoryContextAllocZero(context, sz);
|
||||
SnapBuildRestoreContents(fd, (char *) ondisk->builder.committed.xip, sz, path);
|
||||
COMP_CRC32C(checksum, ondisk->builder.committed.xip, sz);
|
||||
}
|
||||
|
||||
/* restore catalog modifying xacts information */
|
||||
if (ondisk.builder.catchange.xcnt > 0)
|
||||
if (ondisk->builder.catchange.xcnt > 0)
|
||||
{
|
||||
sz = sizeof(TransactionId) * ondisk.builder.catchange.xcnt;
|
||||
ondisk.builder.catchange.xip = MemoryContextAllocZero(builder->context, sz);
|
||||
SnapBuildRestoreContents(fd, (char *) ondisk.builder.catchange.xip, sz, path);
|
||||
COMP_CRC32C(checksum, ondisk.builder.catchange.xip, sz);
|
||||
sz = sizeof(TransactionId) * ondisk->builder.catchange.xcnt;
|
||||
ondisk->builder.catchange.xip = MemoryContextAllocZero(context, sz);
|
||||
SnapBuildRestoreContents(fd, (char *) ondisk->builder.catchange.xip, sz, path);
|
||||
COMP_CRC32C(checksum, ondisk->builder.catchange.xip, sz);
|
||||
}
|
||||
|
||||
if (CloseTransientFile(fd) != 0)
|
||||
@ -1775,11 +1771,36 @@ SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
|
||||
FIN_CRC32C(checksum);
|
||||
|
||||
/* verify checksum of what we've read */
|
||||
if (!EQ_CRC32C(checksum, ondisk.checksum))
|
||||
if (!EQ_CRC32C(checksum, ondisk->checksum))
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_DATA_CORRUPTED),
|
||||
errmsg("checksum mismatch for snapbuild state file \"%s\": is %u, should be %u",
|
||||
path, checksum, ondisk.checksum)));
|
||||
path, checksum, ondisk->checksum)));
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* Restore a snapshot into 'builder' if previously one has been stored at the
|
||||
* location indicated by 'lsn'. Returns true if successful, false otherwise.
|
||||
*/
|
||||
static bool
|
||||
SnapBuildRestore(SnapBuild *builder, XLogRecPtr lsn)
|
||||
{
|
||||
SnapBuildOnDisk ondisk;
|
||||
char path[MAXPGPATH];
|
||||
|
||||
/* no point in loading a snapshot if we're already there */
|
||||
if (builder->state == SNAPBUILD_CONSISTENT)
|
||||
return false;
|
||||
|
||||
sprintf(path, "%s/%X-%X.snap",
|
||||
PG_LOGICAL_SNAPSHOTS_DIR,
|
||||
LSN_FORMAT_ARGS(lsn));
|
||||
|
||||
/* validate and restore the snapshot to 'ondisk' */
|
||||
if (!SnapBuildRestoreSnapshot(&ondisk, path, builder->context, true))
|
||||
return false;
|
||||
|
||||
/*
|
||||
* ok, we now have a sensible snapshot here, figure out if it has more
|
||||
|
||||
@ -3453,6 +3453,12 @@ construct_array_builtin(Datum *elems, int nelems, Oid elmtype)
|
||||
elmalign = TYPALIGN_SHORT;
|
||||
break;
|
||||
|
||||
case XIDOID:
|
||||
elmlen = sizeof(TransactionId);
|
||||
elmbyval = true;
|
||||
elmalign = TYPALIGN_INT;
|
||||
break;
|
||||
|
||||
default:
|
||||
elog(ERROR, "type %u not supported by construct_array_builtin()", elmtype);
|
||||
/* keep compiler quiet */
|
||||
|
||||
@ -15,6 +15,10 @@
|
||||
#include "access/xlogdefs.h"
|
||||
#include "utils/snapmgr.h"
|
||||
|
||||
/*
|
||||
* Please keep get_snapbuild_state_desc() (located in the pg_logicalinspect
|
||||
* module) updated if a change needs to be made to SnapBuildState.
|
||||
*/
|
||||
typedef enum
|
||||
{
|
||||
/*
|
||||
|
||||
@ -193,4 +193,7 @@ typedef struct SnapBuildOnDisk
|
||||
/* variable amount of TransactionIds follows */
|
||||
} SnapBuildOnDisk;
|
||||
|
||||
extern bool SnapBuildRestoreSnapshot(SnapBuildOnDisk *ondisk, const char *path,
|
||||
MemoryContext context, bool missing_ok);
|
||||
|
||||
#endif /* SNAPBUILD_INTERNAL_H */
|
||||
|
||||
Reference in New Issue
Block a user