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	This allows tools that read the WAL sequentially to identify (possible) redo points when they're reached, rather than only being able to detect them in retrospect when XLOG_CHECKPOINT_ONLINE is found, possibly much later in the WAL stream. There are other possible applications as well; see the discussion links below. Any redo location that precedes the checkpoint location should now point to an XLOG_CHECKPOINT_REDO record, so add a cross-check to verify this. While adjusting the code in CreateCheckPoint() for this patch, I made it call WALInsertLockAcquireExclusive a bit later than before, since there appears to be no need for it to be held while checking whether the system is idle, whether this is an end-of-recovery checkpoint, or what the current timeline is. Bump XLOG_PAGE_MAGIC. Patch by me, based in part on earlier work from Dilip Kumar. Review by Dilip Kumar, Amit Kapila, Andres Freund, and Michael Paquier. Discussion: http://postgr.es/m/CA+TgmoYy-Vc6G9QKcAKNksCa29cv__czr+N9X_QCxEfQVpp_8w@mail.gmail.com Discussion: http://postgr.es/m/20230614194717.jyuw3okxup4cvtbt%40awork3.anarazel.de Discussion: http://postgr.es/m/CA+hUKG+b2ego8=YNW2Ohe9QmSiReh1-ogrv8V_WZpJTqP3O+2w@mail.gmail.com
		
			
				
	
	
		
			166 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			SQL
		
	
	
	
	
	
			
		
		
	
	
			166 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			SQL
		
	
	
	
	
	
CREATE EXTENSION pg_walinspect;
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-- Mask DETAIL messages as these could refer to current LSN positions.
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\set VERBOSITY terse
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-- Make sure checkpoints don't interfere with the test.
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SELECT 'init' FROM pg_create_physical_replication_slot('regress_pg_walinspect_slot', true, false);
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CREATE TABLE sample_tbl(col1 int, col2 int);
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-- Save some LSNs for comparisons.
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SELECT pg_current_wal_lsn() AS wal_lsn1 \gset
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INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2);
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SELECT pg_current_wal_lsn() AS wal_lsn2 \gset
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INSERT INTO sample_tbl SELECT * FROM generate_series(3, 4);
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-- ===================================================================
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-- Tests for input validation
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-- ===================================================================
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-- Invalid input LSN.
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SELECT * FROM pg_get_wal_record_info('0/0');
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-- Invalid start LSN.
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SELECT * FROM pg_get_wal_records_info('0/0', :'wal_lsn1');
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SELECT * FROM pg_get_wal_stats('0/0', :'wal_lsn1');
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SELECT * FROM pg_get_wal_block_info('0/0', :'wal_lsn1');
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-- Start LSN > End LSN.
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SELECT * FROM pg_get_wal_records_info(:'wal_lsn2', :'wal_lsn1');
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SELECT * FROM pg_get_wal_stats(:'wal_lsn2', :'wal_lsn1');
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SELECT * FROM pg_get_wal_block_info(:'wal_lsn2', :'wal_lsn1');
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-- LSNs with the highest value possible.
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SELECT * FROM pg_get_wal_record_info('FFFFFFFF/FFFFFFFF');
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-- Success with end LSNs.
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
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-- Failures with start LSNs.
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SELECT * FROM pg_get_wal_records_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
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SELECT * FROM pg_get_wal_stats('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
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SELECT * FROM pg_get_wal_block_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
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-- ===================================================================
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-- Tests for all function executions
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-- ===================================================================
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_record_info(:'wal_lsn1');
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2');
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2');
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', :'wal_lsn2');
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-- ===================================================================
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-- Test for filtering out WAL records of a particular table
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-- ===================================================================
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SELECT oid AS sample_tbl_oid FROM pg_class WHERE relname = 'sample_tbl' \gset
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2')
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			WHERE block_ref LIKE concat('%', :'sample_tbl_oid', '%') AND resource_manager = 'Heap';
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-- ===================================================================
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-- Test for filtering out WAL records based on resource_manager and
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-- record_type
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-- ===================================================================
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2')
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			WHERE resource_manager = 'Heap' AND record_type = 'INSERT';
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-- ===================================================================
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-- Tests to get block information from WAL record
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-- ===================================================================
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-- Update table to generate some block data.
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SELECT pg_current_wal_lsn() AS wal_lsn3 \gset
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UPDATE sample_tbl SET col1 = col1 + 1 WHERE col1 = 1;
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SELECT pg_current_wal_lsn() AS wal_lsn4 \gset
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-- Check if we get block data from WAL record.
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn3', :'wal_lsn4')
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  WHERE relfilenode = :'sample_tbl_oid' AND block_data IS NOT NULL;
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-- Force a checkpoint so that the next update will log a full-page image.
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SELECT pg_current_wal_lsn() AS wal_lsn5 \gset
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CHECKPOINT;
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-- Verify that an XLOG_CHECKPOINT_REDO record begins at precisely the redo LSN
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-- of the checkpoint we just performed.
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SELECT redo_lsn FROM pg_control_checkpoint() \gset
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SELECT start_lsn = :'redo_lsn'::pg_lsn AS same_lsn, resource_manager,
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    record_type FROM pg_get_wal_record_info(:'redo_lsn');
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-- This update should produce a full-page image because of the checkpoint.
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UPDATE sample_tbl SET col1 = col1 + 1 WHERE col1 = 2;
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SELECT pg_current_wal_lsn() AS wal_lsn6 \gset
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-- Check if we get FPI from WAL record.
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SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn5', :'wal_lsn6')
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  WHERE relfilenode = :'sample_tbl_oid' AND block_fpi_data IS NOT NULL;
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-- ===================================================================
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-- Tests for permissions
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-- ===================================================================
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CREATE ROLE regress_pg_walinspect;
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- no
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- no
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- no
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_block_info(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- no
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-- Functions accessible by users with role pg_read_server_files.
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GRANT pg_read_server_files TO regress_pg_walinspect;
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_block_info(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes
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REVOKE pg_read_server_files FROM regress_pg_walinspect;
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-- Superuser can grant execute to other users.
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GRANT EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn)
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  TO regress_pg_walinspect;
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GRANT EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn)
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  TO regress_pg_walinspect;
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GRANT EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean)
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  TO regress_pg_walinspect;
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GRANT EXECUTE ON FUNCTION pg_get_wal_block_info(pg_lsn, pg_lsn, boolean)
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  TO regress_pg_walinspect;
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes
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SELECT has_function_privilege('regress_pg_walinspect',
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  'pg_get_wal_block_info(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes
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REVOKE EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn)
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  FROM regress_pg_walinspect;
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REVOKE EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn)
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  FROM regress_pg_walinspect;
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REVOKE EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean)
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  FROM regress_pg_walinspect;
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REVOKE EXECUTE ON FUNCTION pg_get_wal_block_info(pg_lsn, pg_lsn, boolean)
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  FROM regress_pg_walinspect;
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-- ===================================================================
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-- Clean up
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-- ===================================================================
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DROP ROLE regress_pg_walinspect;
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SELECT pg_drop_replication_slot('regress_pg_walinspect_slot');
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DROP TABLE sample_tbl;
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DROP EXTENSION pg_walinspect;
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