mirror of https://github.com/postgres/postgres
Provides similar functionality to pg_waldump, but from a SQL interface rather than a separate utility. Author: Bharath Rupireddy Reviewed-by: Greg Stark, Kyotaro Horiguchi, Andres Freund, Ashutosh Sharma, Nitin Jadhav, RKN Sai Krishna Discussion: https://postgr.es/m/CALj2ACUGUYXsEQdKhEdsBzhGEyF3xggvLdD8C0VT72TNEfOiog%40mail.gmail.compull/81/head
Jeff Davis
3 years ago
parent
708007dced
commit
2258e76f90
@ -0,0 +1,4 @@ |
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# Generated subdirectories |
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/log/ |
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/results/ |
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/tmp_check/ |
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@ -0,0 +1,23 @@ |
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# contrib/pg_walinspect/Makefile
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MODULE_big = pg_walinspect
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OBJS = \
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$(WIN32RES) \
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pg_walinspect.o
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PGFILEDESC = "pg_walinspect - functions to inspect contents of PostgreSQL Write-Ahead Log"
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EXTENSION = pg_walinspect
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DATA = pg_walinspect--1.0.sql
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REGRESS = pg_walinspect
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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_walinspect
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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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@ -0,0 +1,165 @@ |
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CREATE EXTENSION pg_walinspect; |
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CREATE TABLE sample_tbl(col1 int, col2 int); |
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-- Make sure checkpoints don't interfere with the test. |
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SELECT lsn as wal_lsn1 FROM |
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pg_create_physical_replication_slot('regress_pg_walinspect_slot', true, false) |
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\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(1, 2); |
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-- =================================================================== |
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-- Tests for input validation |
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-- =================================================================== |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn2', :'wal_lsn1'); -- ERROR |
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ERROR: WAL start LSN must be less than end LSN |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn2', :'wal_lsn1'); -- ERROR |
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ERROR: WAL start LSN must be less than end LSN |
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-- =================================================================== |
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-- Tests for all function executions |
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-- =================================================================== |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_record_info(:'wal_lsn1'); |
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ok |
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---- |
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t |
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(1 row) |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2'); |
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ok |
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---- |
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t |
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(1 row) |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info_till_end_of_wal(:'wal_lsn1'); |
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ok |
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---- |
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t |
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(1 row) |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2'); |
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ok |
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---- |
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t |
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(1 row) |
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SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats_till_end_of_wal(:'wal_lsn1'); |
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ok |
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---- |
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t |
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(1 row) |
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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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ok |
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---- |
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t |
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(1 row) |
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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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ok |
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---- |
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t |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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f |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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f |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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f |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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SELECT has_function_privilege('regress_pg_walinspect', |
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'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- yes |
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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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has_function_privilege |
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------------------------ |
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t |
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(1 row) |
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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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-- =================================================================== |
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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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pg_drop_replication_slot |
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-------------------------- |
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(1 row) |
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DROP TABLE sample_tbl; |
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@ -0,0 +1,118 @@ |
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/* contrib/pg_walinspect/pg_walinspect--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_walinspect" to load this file. \quit |
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-- |
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-- pg_get_wal_record_info() |
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-- |
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CREATE FUNCTION pg_get_wal_record_info(IN in_lsn pg_lsn, |
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OUT start_lsn pg_lsn, |
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OUT end_lsn pg_lsn, |
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OUT prev_lsn pg_lsn, |
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OUT xid xid, |
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OUT resource_manager text, |
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OUT record_type text, |
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OUT record_length int4, |
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OUT main_data_length int4, |
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OUT fpi_length int4, |
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OUT description text, |
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OUT block_ref text |
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) |
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AS 'MODULE_PATHNAME', 'pg_get_wal_record_info' |
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LANGUAGE C STRICT PARALLEL SAFE; |
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REVOKE EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) FROM PUBLIC; |
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GRANT EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) TO pg_read_server_files; |
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-- |
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-- pg_get_wal_records_info() |
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-- |
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CREATE FUNCTION pg_get_wal_records_info(IN start_lsn pg_lsn, |
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IN end_lsn pg_lsn, |
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OUT start_lsn pg_lsn, |
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OUT end_lsn pg_lsn, |
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OUT prev_lsn pg_lsn, |
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OUT xid xid, |
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OUT resource_manager text, |
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OUT record_type text, |
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OUT record_length int4, |
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OUT main_data_length int4, |
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OUT fpi_length int4, |
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OUT description text, |
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OUT block_ref text |
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) |
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RETURNS SETOF record |
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AS 'MODULE_PATHNAME', 'pg_get_wal_records_info' |
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LANGUAGE C STRICT PARALLEL SAFE; |
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REVOKE EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) FROM PUBLIC; |
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GRANT EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) TO pg_read_server_files; |
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-- |
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-- pg_get_wal_records_info_till_end_of_wal() |
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-- |
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CREATE FUNCTION pg_get_wal_records_info_till_end_of_wal(IN start_lsn pg_lsn, |
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OUT start_lsn pg_lsn, |
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OUT end_lsn pg_lsn, |
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OUT prev_lsn pg_lsn, |
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OUT xid xid, |
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OUT resource_manager text, |
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OUT record_type text, |
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OUT record_length int4, |
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OUT main_data_length int4, |
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OUT fpi_length int4, |
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OUT description text, |
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OUT block_ref text |
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) |
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RETURNS SETOF record |
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AS 'MODULE_PATHNAME', 'pg_get_wal_records_info_till_end_of_wal' |
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LANGUAGE C STRICT PARALLEL SAFE; |
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REVOKE EXECUTE ON FUNCTION pg_get_wal_records_info_till_end_of_wal(pg_lsn) FROM PUBLIC; |
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GRANT EXECUTE ON FUNCTION pg_get_wal_records_info_till_end_of_wal(pg_lsn) TO pg_read_server_files; |
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-- |
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-- pg_get_wal_stats() |
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-- |
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CREATE FUNCTION pg_get_wal_stats(IN start_lsn pg_lsn, |
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IN end_lsn pg_lsn, |
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IN per_record boolean DEFAULT false, |
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OUT "resource_manager/record_type" text, |
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OUT count int8, |
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OUT count_percentage float4, |
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OUT record_size int8, |
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OUT record_size_percentage float4, |
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OUT fpi_size int8, |
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OUT fpi_size_percentage float4, |
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OUT combined_size int8, |
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OUT combined_size_percentage float4 |
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) |
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RETURNS SETOF record |
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AS 'MODULE_PATHNAME', 'pg_get_wal_stats' |
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LANGUAGE C STRICT PARALLEL SAFE; |
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REVOKE EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean) FROM PUBLIC; |
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GRANT EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean) TO pg_read_server_files; |
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-- |
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-- pg_get_wal_stats_till_end_of_wal() |
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-- |
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CREATE FUNCTION pg_get_wal_stats_till_end_of_wal(IN start_lsn pg_lsn, |
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IN per_record boolean DEFAULT false, |
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OUT "resource_manager/record_type" text, |
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OUT count int8, |
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OUT count_percentage float4, |
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OUT record_size int8, |
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OUT record_size_percentage float4, |
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OUT fpi_size int8, |
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OUT fpi_size_percentage float4, |
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OUT combined_size int8, |
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OUT combined_size_percentage float4 |
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) |
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RETURNS SETOF record |
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AS 'MODULE_PATHNAME', 'pg_get_wal_stats_till_end_of_wal' |
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LANGUAGE C STRICT PARALLEL SAFE; |
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REVOKE EXECUTE ON FUNCTION pg_get_wal_stats_till_end_of_wal(pg_lsn, boolean) FROM PUBLIC; |
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GRANT EXECUTE ON FUNCTION pg_get_wal_stats_till_end_of_wal(pg_lsn, boolean) TO pg_read_server_files; |
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@ -0,0 +1,629 @@ |
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/*-------------------------------------------------------------------------
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* |
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* pg_walinspect.c |
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* Functions to inspect contents of PostgreSQL Write-Ahead Log |
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* |
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* Copyright (c) 2022, PostgreSQL Global Development Group |
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* |
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* IDENTIFICATION |
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* contrib/pg_walinspect/pg_walinspect.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 "access/xlog.h" |
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#include "access/xlog_internal.h" |
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#include "access/xlogreader.h" |
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#include "access/xlogrecovery.h" |
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#include "access/xlogstats.h" |
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#include "access/xlogutils.h" |
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#include "funcapi.h" |
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#include "miscadmin.h" |
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#include "utils/builtins.h" |
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#include "utils/pg_lsn.h" |
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/*
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* NOTE: For any code change or issue fix here, it is highly recommended to |
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* give a thought about doing the same in pg_waldump tool as well. |
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*/ |
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PG_MODULE_MAGIC; |
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PG_FUNCTION_INFO_V1(pg_get_wal_record_info); |
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PG_FUNCTION_INFO_V1(pg_get_wal_records_info); |
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PG_FUNCTION_INFO_V1(pg_get_wal_records_info_till_end_of_wal); |
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PG_FUNCTION_INFO_V1(pg_get_wal_stats); |
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PG_FUNCTION_INFO_V1(pg_get_wal_stats_till_end_of_wal); |
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static bool IsFutureLSN(XLogRecPtr lsn, XLogRecPtr *curr_lsn); |
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static XLogReaderState *InitXLogReaderState(XLogRecPtr lsn, |
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XLogRecPtr *first_record); |
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static XLogRecord *ReadNextXLogRecord(XLogReaderState *xlogreader, |
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XLogRecPtr first_record); |
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static void GetWALRecordInfo(XLogReaderState *record, XLogRecPtr lsn, |
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Datum *values, bool *nulls, uint32 ncols); |
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static XLogRecPtr ValidateInputLSNs(bool till_end_of_wal, |
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XLogRecPtr start_lsn, XLogRecPtr end_lsn); |
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static void GetWALRecordsInfo(FunctionCallInfo fcinfo, XLogRecPtr start_lsn, |
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XLogRecPtr end_lsn); |
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static void GetXLogSummaryStats(XLogStats * stats, ReturnSetInfo *rsinfo, |
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Datum *values, bool *nulls, uint32 ncols, |
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bool stats_per_record); |
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static void FillXLogStatsRow(const char *name, uint64 n, uint64 total_count, |
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uint64 rec_len, uint64 total_rec_len, |
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uint64 fpi_len, uint64 total_fpi_len, |
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uint64 tot_len, uint64 total_len, |
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Datum *values, bool *nulls, uint32 ncols); |
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static void GetWalStats(FunctionCallInfo fcinfo, XLogRecPtr start_lsn, |
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XLogRecPtr end_lsn, bool stats_per_record); |
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/*
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* Check if the given LSN is in future. Also, return the LSN up to which the |
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* server has WAL. |
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*/ |
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static bool |
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IsFutureLSN(XLogRecPtr lsn, XLogRecPtr *curr_lsn) |
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{ |
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/*
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* We determine the current LSN of the server similar to how page_read |
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* callback read_local_xlog_page_no_wait does. |
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*/ |
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if (!RecoveryInProgress()) |
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*curr_lsn = GetFlushRecPtr(NULL); |
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else |
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*curr_lsn = GetXLogReplayRecPtr(NULL); |
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Assert(!XLogRecPtrIsInvalid(*curr_lsn)); |
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if (lsn >= *curr_lsn) |
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return true; |
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return false; |
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} |
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/*
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* Intialize WAL reader and identify first valid LSN. |
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*/ |
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static XLogReaderState * |
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InitXLogReaderState(XLogRecPtr lsn, XLogRecPtr *first_record) |
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{ |
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XLogReaderState *xlogreader; |
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|
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/*
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* Reading WAL below the first page of the first sgements isn't allowed. |
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* This is a bootstrap WAL page and the page_read callback fails to read |
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* it. |
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*/ |
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if (lsn < XLOG_BLCKSZ) |
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ereport(ERROR, |
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(errmsg("could not read WAL at LSN %X/%X", |
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LSN_FORMAT_ARGS(lsn)))); |
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|
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xlogreader = XLogReaderAllocate(wal_segment_size, NULL, |
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XL_ROUTINE(.page_read = &read_local_xlog_page_no_wait, |
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.segment_open = &wal_segment_open, |
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.segment_close = &wal_segment_close), |
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NULL); |
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|
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if (xlogreader == NULL) |
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ereport(ERROR, |
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(errcode(ERRCODE_OUT_OF_MEMORY), |
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errmsg("out of memory"), |
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errdetail("Failed while allocating a WAL reading processor."))); |
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|
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/* first find a valid recptr to start from */ |
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*first_record = XLogFindNextRecord(xlogreader, lsn); |
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|
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if (XLogRecPtrIsInvalid(*first_record)) |
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ereport(ERROR, |
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(errmsg("could not find a valid record after %X/%X", |
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LSN_FORMAT_ARGS(lsn)))); |
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return xlogreader; |
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} |
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|
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/*
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* Read next WAL record. |
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* |
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* By design, to be less intrusive in a running system, no slot is allocated |
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* to reserve the WAL we're about to read. Therefore this function can |
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* encounter read errors for historical WAL. |
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* |
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* We guard against ordinary errors trying to read WAL that hasn't been |
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* written yet by limiting end_lsn to the flushed WAL, but that can also |
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* encounter errors if the flush pointer falls in the middle of a record. |
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*/ |
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static XLogRecord * |
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ReadNextXLogRecord(XLogReaderState *xlogreader, XLogRecPtr first_record) |
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{ |
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XLogRecord *record; |
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char *errormsg; |
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|
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record = XLogReadRecord(xlogreader, &errormsg); |
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|
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if (record == NULL) |
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{ |
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if (errormsg) |
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ereport(ERROR, |
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(errcode_for_file_access(), |
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errmsg("could not read WAL at %X/%X: %s", |
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LSN_FORMAT_ARGS(first_record), errormsg))); |
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else |
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ereport(ERROR, |
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(errcode_for_file_access(), |
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errmsg("could not read WAL at %X/%X", |
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LSN_FORMAT_ARGS(first_record)))); |
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} |
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|
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return record; |
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} |
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|
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/*
|
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* Get a single WAL record info. |
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*/ |
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static void |
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GetWALRecordInfo(XLogReaderState *record, XLogRecPtr lsn, |
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Datum *values, bool *nulls, uint32 ncols) |
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{ |
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const char *id; |
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RmgrData desc; |
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uint32 fpi_len = 0; |
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StringInfoData rec_desc; |
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StringInfoData rec_blk_ref; |
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uint32 main_data_len; |
||||
int i = 0; |
||||
|
||||
desc = GetRmgr(XLogRecGetRmid(record)); |
||||
id = desc.rm_identify(XLogRecGetInfo(record)); |
||||
|
||||
if (id == NULL) |
||||
id = psprintf("UNKNOWN (%x)", XLogRecGetInfo(record) & ~XLR_INFO_MASK); |
||||
|
||||
initStringInfo(&rec_desc); |
||||
desc.rm_desc(&rec_desc, record); |
||||
|
||||
/* Block references. */ |
||||
initStringInfo(&rec_blk_ref); |
||||
XLogRecGetBlockRefInfo(record, false, true, &rec_blk_ref, &fpi_len); |
||||
|
||||
main_data_len = XLogRecGetDataLen(record); |
||||
|
||||
values[i++] = LSNGetDatum(lsn); |
||||
values[i++] = LSNGetDatum(record->EndRecPtr); |
||||
values[i++] = LSNGetDatum(XLogRecGetPrev(record)); |
||||
values[i++] = TransactionIdGetDatum(XLogRecGetXid(record)); |
||||
values[i++] = CStringGetTextDatum(desc.rm_name); |
||||
values[i++] = CStringGetTextDatum(id); |
||||
values[i++] = UInt32GetDatum(XLogRecGetTotalLen(record)); |
||||
values[i++] = UInt32GetDatum(main_data_len); |
||||
values[i++] = UInt32GetDatum(fpi_len); |
||||
values[i++] = CStringGetTextDatum(rec_desc.data); |
||||
values[i++] = CStringGetTextDatum(rec_blk_ref.data); |
||||
|
||||
Assert(i == ncols); |
||||
} |
||||
|
||||
/*
|
||||
* Get WAL record info. |
||||
* |
||||
* This function emits an error if a future WAL LSN i.e. WAL LSN the database |
||||
* system doesn't know about is specified. |
||||
*/ |
||||
Datum |
||||
pg_get_wal_record_info(PG_FUNCTION_ARGS) |
||||
{ |
||||
#define PG_GET_WAL_RECORD_INFO_COLS 11 |
||||
Datum result; |
||||
Datum values[PG_GET_WAL_RECORD_INFO_COLS]; |
||||
bool nulls[PG_GET_WAL_RECORD_INFO_COLS]; |
||||
XLogRecPtr lsn; |
||||
XLogRecPtr curr_lsn; |
||||
XLogRecPtr first_record; |
||||
XLogReaderState *xlogreader; |
||||
TupleDesc tupdesc; |
||||
HeapTuple tuple; |
||||
|
||||
lsn = PG_GETARG_LSN(0); |
||||
|
||||
if (IsFutureLSN(lsn, &curr_lsn)) |
||||
{ |
||||
/*
|
||||
* GetFlushRecPtr or GetXLogReplayRecPtr gives "end+1" LSN of the last |
||||
* record flushed or replayed respectively. But let's use the LSN up |
||||
* to "end" in user facing message. |
||||
*/ |
||||
ereport(ERROR, |
||||
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), |
||||
errmsg("cannot accept future input LSN"), |
||||
errdetail("Last known WAL LSN on the database system is at %X/%X.", |
||||
LSN_FORMAT_ARGS(curr_lsn)))); |
||||
} |
||||
|
||||
/* Build a tuple descriptor for our result type. */ |
||||
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) |
||||
elog(ERROR, "return type must be a row type"); |
||||
|
||||
xlogreader = InitXLogReaderState(lsn, &first_record); |
||||
|
||||
(void) ReadNextXLogRecord(xlogreader, first_record); |
||||
|
||||
MemSet(values, 0, sizeof(values)); |
||||
MemSet(nulls, 0, sizeof(nulls)); |
||||
|
||||
GetWALRecordInfo(xlogreader, first_record, values, nulls, |
||||
PG_GET_WAL_RECORD_INFO_COLS); |
||||
|
||||
XLogReaderFree(xlogreader); |
||||
|
||||
tuple = heap_form_tuple(tupdesc, values, nulls); |
||||
result = HeapTupleGetDatum(tuple); |
||||
|
||||
PG_RETURN_DATUM(result); |
||||
#undef PG_GET_WAL_RECORD_INFO_COLS |
||||
} |
||||
|
||||
/*
|
||||
* Validate the input LSNs and compute end LSN for till_end_of_wal versions. |
||||
*/ |
||||
static XLogRecPtr |
||||
ValidateInputLSNs(bool till_end_of_wal, XLogRecPtr start_lsn, |
||||
XLogRecPtr end_lsn) |
||||
{ |
||||
XLogRecPtr curr_lsn; |
||||
|
||||
if (IsFutureLSN(start_lsn, &curr_lsn)) |
||||
{ |
||||
/*
|
||||
* GetFlushRecPtr or GetXLogReplayRecPtr gives "end+1" LSN of the last |
||||
* record flushed or replayed respectively. But let's use the LSN up |
||||
* to "end" in user facing message. |
||||
*/ |
||||
ereport(ERROR, |
||||
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), |
||||
errmsg("cannot accept future start LSN"), |
||||
errdetail("Last known WAL LSN on the database system is at %X/%X.", |
||||
LSN_FORMAT_ARGS(curr_lsn)))); |
||||
} |
||||
|
||||
if (till_end_of_wal) |
||||
end_lsn = curr_lsn; |
||||
|
||||
if (end_lsn > curr_lsn) |
||||
ereport(ERROR, |
||||
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), |
||||
errmsg("cannot accept future end LSN"), |
||||
errdetail("Last known WAL LSN on the database system is at %X/%X.", |
||||
LSN_FORMAT_ARGS(curr_lsn)))); |
||||
|
||||
if (start_lsn >= end_lsn) |
||||
ereport(ERROR, |
||||
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), |
||||
errmsg("WAL start LSN must be less than end LSN"))); |
||||
|
||||
return end_lsn; |
||||
} |
||||
|
||||
/*
|
||||
* Get info and data of all WAL records between start LSN and end LSN. |
||||
*/ |
||||
static void |
||||
GetWALRecordsInfo(FunctionCallInfo fcinfo, XLogRecPtr start_lsn, |
||||
XLogRecPtr end_lsn) |
||||
{ |
||||
#define PG_GET_WAL_RECORDS_INFO_COLS 11 |
||||
XLogRecPtr first_record; |
||||
XLogReaderState *xlogreader; |
||||
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; |
||||
Datum values[PG_GET_WAL_RECORDS_INFO_COLS]; |
||||
bool nulls[PG_GET_WAL_RECORDS_INFO_COLS]; |
||||
|
||||
SetSingleFuncCall(fcinfo, 0); |
||||
|
||||
xlogreader = InitXLogReaderState(start_lsn, &first_record); |
||||
|
||||
Assert(xlogreader); |
||||
|
||||
MemSet(values, 0, sizeof(values)); |
||||
MemSet(nulls, 0, sizeof(nulls)); |
||||
|
||||
for (;;) |
||||
{ |
||||
(void) ReadNextXLogRecord(xlogreader, first_record); |
||||
|
||||
if (xlogreader->EndRecPtr <= end_lsn) |
||||
{ |
||||
GetWALRecordInfo(xlogreader, xlogreader->currRecPtr, values, nulls, |
||||
PG_GET_WAL_RECORDS_INFO_COLS); |
||||
|
||||
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, |
||||
values, nulls); |
||||
} |
||||
|
||||
/* if we read up to end_lsn, we're done */ |
||||
if (xlogreader->EndRecPtr >= end_lsn) |
||||
break; |
||||
|
||||
CHECK_FOR_INTERRUPTS(); |
||||
} |
||||
|
||||
XLogReaderFree(xlogreader); |
||||
|
||||
#undef PG_GET_WAL_RECORDS_INFO_COLS |
||||
} |
||||
|
||||
/*
|
||||
* Get info and data of all WAL records between start LSN and end LSN. |
||||
* |
||||
* This function emits an error if a future start or end WAL LSN i.e. WAL LSN |
||||
* the database system doesn't know about is specified. |
||||
*/ |
||||
Datum |
||||
pg_get_wal_records_info(PG_FUNCTION_ARGS) |
||||
{ |
||||
XLogRecPtr start_lsn; |
||||
XLogRecPtr end_lsn; |
||||
|
||||
start_lsn = PG_GETARG_LSN(0); |
||||
end_lsn = PG_GETARG_LSN(1); |
||||
|
||||
end_lsn = ValidateInputLSNs(false, start_lsn, end_lsn); |
||||
|
||||
GetWALRecordsInfo(fcinfo, start_lsn, end_lsn); |
||||
|
||||
PG_RETURN_VOID(); |
||||
} |
||||
|
||||
/*
|
||||
* Get info and data of all WAL records from start LSN till end of WAL. |
||||
* |
||||
* This function emits an error if a future start i.e. WAL LSN the database |
||||
* system doesn't know about is specified. |
||||
*/ |
||||
Datum |
||||
pg_get_wal_records_info_till_end_of_wal(PG_FUNCTION_ARGS) |
||||
{ |
||||
XLogRecPtr start_lsn; |
||||
XLogRecPtr end_lsn = InvalidXLogRecPtr; |
||||
|
||||
start_lsn = PG_GETARG_LSN(0); |
||||
|
||||
end_lsn = ValidateInputLSNs(true, start_lsn, end_lsn); |
||||
|
||||
GetWALRecordsInfo(fcinfo, start_lsn, end_lsn); |
||||
|
||||
PG_RETURN_VOID(); |
||||
} |
||||
|
||||
/*
|
||||
* Fill single row of record counts and sizes for an rmgr or record. |
||||
*/ |
||||
static void |
||||
FillXLogStatsRow(const char *name, |
||||
uint64 n, uint64 total_count, |
||||
uint64 rec_len, uint64 total_rec_len, |
||||
uint64 fpi_len, uint64 total_fpi_len, |
||||
uint64 tot_len, uint64 total_len, |
||||
Datum *values, bool *nulls, uint32 ncols) |
||||
{ |
||||
double n_pct, |
||||
rec_len_pct, |
||||
fpi_len_pct, |
||||
tot_len_pct; |
||||
int i = 0; |
||||
|
||||
n_pct = 0; |
||||
if (total_count != 0) |
||||
n_pct = 100 * (double) n / total_count; |
||||
|
||||
rec_len_pct = 0; |
||||
if (total_rec_len != 0) |
||||
rec_len_pct = 100 * (double) rec_len / total_rec_len; |
||||
|
||||
fpi_len_pct = 0; |
||||
if (total_fpi_len != 0) |
||||
fpi_len_pct = 100 * (double) fpi_len / total_fpi_len; |
||||
|
||||
tot_len_pct = 0; |
||||
if (total_len != 0) |
||||
tot_len_pct = 100 * (double) tot_len / total_len; |
||||
|
||||
values[i++] = CStringGetTextDatum(name); |
||||
values[i++] = Int64GetDatum(n); |
||||
values[i++] = Float4GetDatum(n_pct); |
||||
values[i++] = Int64GetDatum(rec_len); |
||||
values[i++] = Float4GetDatum(rec_len_pct); |
||||
values[i++] = Int64GetDatum(fpi_len); |
||||
values[i++] = Float4GetDatum(fpi_len_pct); |
||||
values[i++] = Int64GetDatum(tot_len); |
||||
values[i++] = Float4GetDatum(tot_len_pct); |
||||
|
||||
Assert(i == ncols); |
||||
} |
||||
|
||||
/*
|
||||
* Get summary statistics about the records seen so far. |
||||
*/ |
||||
static void |
||||
GetXLogSummaryStats(XLogStats *stats, ReturnSetInfo *rsinfo, |
||||
Datum *values, bool *nulls, uint32 ncols, |
||||
bool stats_per_record) |
||||
{ |
||||
uint64 total_count = 0; |
||||
uint64 total_rec_len = 0; |
||||
uint64 total_fpi_len = 0; |
||||
uint64 total_len = 0; |
||||
int ri; |
||||
|
||||
/*
|
||||
* Each row shows its percentages of the total, so make a first pass to |
||||
* calculate column totals. |
||||
*/ |
||||
for (ri = 0; ri <= RM_MAX_ID; ri++) |
||||
{ |
||||
if (!RmgrIdIsValid(ri)) |
||||
continue; |
||||
|
||||
total_count += stats->rmgr_stats[ri].count; |
||||
total_rec_len += stats->rmgr_stats[ri].rec_len; |
||||
total_fpi_len += stats->rmgr_stats[ri].fpi_len; |
||||
} |
||||
total_len = total_rec_len + total_fpi_len; |
||||
|
||||
for (ri = 0; ri <= RM_MAX_ID; ri++) |
||||
{ |
||||
uint64 count; |
||||
uint64 rec_len; |
||||
uint64 fpi_len; |
||||
uint64 tot_len; |
||||
RmgrData desc; |
||||
|
||||
if (!RmgrIdIsValid(ri)) |
||||
continue; |
||||
|
||||
if (!RmgrIdExists(ri)) |
||||
continue; |
||||
|
||||
desc = GetRmgr(ri); |
||||
|
||||
if (stats_per_record) |
||||
{ |
||||
int rj; |
||||
|
||||
for (rj = 0; rj < MAX_XLINFO_TYPES; rj++) |
||||
{ |
||||
const char *id; |
||||
|
||||
count = stats->record_stats[ri][rj].count; |
||||
rec_len = stats->record_stats[ri][rj].rec_len; |
||||
fpi_len = stats->record_stats[ri][rj].fpi_len; |
||||
tot_len = rec_len + fpi_len; |
||||
|
||||
/* Skip undefined combinations and ones that didn't occur */ |
||||
if (count == 0) |
||||
continue; |
||||
|
||||
/* the upper four bits in xl_info are the rmgr's */ |
||||
id = desc.rm_identify(rj << 4); |
||||
if (id == NULL) |
||||
id = psprintf("UNKNOWN (%x)", rj << 4); |
||||
|
||||
FillXLogStatsRow(psprintf("%s/%s", desc.rm_name, id), count, |
||||
total_count, rec_len, total_rec_len, fpi_len, |
||||
total_fpi_len, tot_len, total_len, |
||||
values, nulls, ncols); |
||||
|
||||
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, |
||||
values, nulls); |
||||
} |
||||
} |
||||
else |
||||
{ |
||||
count = stats->rmgr_stats[ri].count; |
||||
rec_len = stats->rmgr_stats[ri].rec_len; |
||||
fpi_len = stats->rmgr_stats[ri].fpi_len; |
||||
tot_len = rec_len + fpi_len; |
||||
|
||||
FillXLogStatsRow(desc.rm_name, count, total_count, rec_len, |
||||
total_rec_len, fpi_len, total_fpi_len, tot_len, |
||||
total_len, values, nulls, ncols); |
||||
|
||||
tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, |
||||
values, nulls); |
||||
} |
||||
} |
||||
} |
||||
|
||||
/*
|
||||
* Get WAL stats between start LSN and end LSN. |
||||
*/ |
||||
static void |
||||
GetWalStats(FunctionCallInfo fcinfo, XLogRecPtr start_lsn, |
||||
XLogRecPtr end_lsn, bool stats_per_record) |
||||
{ |
||||
#define PG_GET_WAL_STATS_COLS 9 |
||||
XLogRecPtr first_record; |
||||
XLogReaderState *xlogreader; |
||||
XLogStats stats; |
||||
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; |
||||
Datum values[PG_GET_WAL_STATS_COLS]; |
||||
bool nulls[PG_GET_WAL_STATS_COLS]; |
||||
|
||||
SetSingleFuncCall(fcinfo, 0); |
||||
|
||||
xlogreader = InitXLogReaderState(start_lsn, &first_record); |
||||
|
||||
MemSet(&stats, 0, sizeof(stats)); |
||||
|
||||
for (;;) |
||||
{ |
||||
(void) ReadNextXLogRecord(xlogreader, first_record); |
||||
|
||||
if (xlogreader->EndRecPtr <= end_lsn) |
||||
XLogRecStoreStats(&stats, xlogreader); |
||||
|
||||
/* if we read up to end_lsn, we're done */ |
||||
if (xlogreader->EndRecPtr >= end_lsn) |
||||
break; |
||||
|
||||
CHECK_FOR_INTERRUPTS(); |
||||
} |
||||
|
||||
XLogReaderFree(xlogreader); |
||||
|
||||
MemSet(values, 0, sizeof(values)); |
||||
MemSet(nulls, 0, sizeof(nulls)); |
||||
|
||||
GetXLogSummaryStats(&stats, rsinfo, values, nulls, |
||||
PG_GET_WAL_STATS_COLS, |
||||
stats_per_record); |
||||
|
||||
#undef PG_GET_WAL_STATS_COLS |
||||
} |
||||
|
||||
/*
|
||||
* Get stats of all WAL records between start LSN and end LSN. |
||||
* |
||||
* This function emits an error if a future start or end WAL LSN i.e. WAL LSN |
||||
* the database system doesn't know about is specified. |
||||
*/ |
||||
Datum |
||||
pg_get_wal_stats(PG_FUNCTION_ARGS) |
||||
{ |
||||
XLogRecPtr start_lsn; |
||||
XLogRecPtr end_lsn; |
||||
bool stats_per_record; |
||||
|
||||
start_lsn = PG_GETARG_LSN(0); |
||||
end_lsn = PG_GETARG_LSN(1); |
||||
stats_per_record = PG_GETARG_BOOL(2); |
||||
|
||||
end_lsn = ValidateInputLSNs(false, start_lsn, end_lsn); |
||||
|
||||
GetWalStats(fcinfo, start_lsn, end_lsn, stats_per_record); |
||||
|
||||
PG_RETURN_VOID(); |
||||
} |
||||
|
||||
/*
|
||||
* Get stats of all WAL records from start LSN till end of WAL. |
||||
* |
||||
* This function emits an error if a future start i.e. WAL LSN the database |
||||
* system doesn't know about is specified. |
||||
*/ |
||||
Datum |
||||
pg_get_wal_stats_till_end_of_wal(PG_FUNCTION_ARGS) |
||||
{ |
||||
XLogRecPtr start_lsn; |
||||
XLogRecPtr end_lsn = InvalidXLogRecPtr; |
||||
bool stats_per_record; |
||||
|
||||
start_lsn = PG_GETARG_LSN(0); |
||||
stats_per_record = PG_GETARG_BOOL(1); |
||||
|
||||
end_lsn = ValidateInputLSNs(true, start_lsn, end_lsn); |
||||
|
||||
GetWalStats(fcinfo, start_lsn, end_lsn, stats_per_record); |
||||
|
||||
PG_RETURN_VOID(); |
||||
} |
||||
@ -0,0 +1,5 @@ |
||||
# pg_walinspect extension |
||||
comment = 'functions to inspect contents of PostgreSQL Write-Ahead Log' |
||||
default_version = '1.0' |
||||
module_pathname = '$libdir/pg_walinspect' |
||||
relocatable = true |
||||
@ -0,0 +1,120 @@ |
||||
CREATE EXTENSION pg_walinspect; |
||||
|
||||
CREATE TABLE sample_tbl(col1 int, col2 int); |
||||
|
||||
-- Make sure checkpoints don't interfere with the test. |
||||
SELECT lsn as wal_lsn1 FROM |
||||
pg_create_physical_replication_slot('regress_pg_walinspect_slot', true, false) |
||||
\gset |
||||
|
||||
INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2); |
||||
|
||||
SELECT pg_current_wal_lsn() AS wal_lsn2 \gset |
||||
|
||||
INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2); |
||||
|
||||
-- =================================================================== |
||||
-- Tests for input validation |
||||
-- =================================================================== |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn2', :'wal_lsn1'); -- ERROR |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn2', :'wal_lsn1'); -- ERROR |
||||
|
||||
-- =================================================================== |
||||
-- Tests for all function executions |
||||
-- =================================================================== |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_record_info(:'wal_lsn1'); |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2'); |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info_till_end_of_wal(:'wal_lsn1'); |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2'); |
||||
|
||||
SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats_till_end_of_wal(:'wal_lsn1'); |
||||
|
||||
-- =================================================================== |
||||
-- Test for filtering out WAL records of a particular table |
||||
-- =================================================================== |
||||
|
||||
SELECT oid AS sample_tbl_oid FROM pg_class WHERE relname = 'sample_tbl' \gset |
||||
|
||||
SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2') |
||||
WHERE block_ref LIKE concat('%', :'sample_tbl_oid', '%') AND resource_manager = 'Heap'; |
||||
|
||||
-- =================================================================== |
||||
-- Test for filtering out WAL records based on resource_manager and |
||||
-- record_type |
||||
-- =================================================================== |
||||
|
||||
SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2') |
||||
WHERE resource_manager = 'Heap' AND record_type = 'INSERT'; |
||||
|
||||
-- =================================================================== |
||||
-- Tests for permissions |
||||
-- =================================================================== |
||||
CREATE ROLE regress_pg_walinspect; |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- no |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- no |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- no |
||||
|
||||
-- Functions accessible by users with role pg_read_server_files |
||||
|
||||
GRANT pg_read_server_files TO regress_pg_walinspect; |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- yes |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- yes |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes |
||||
|
||||
REVOKE pg_read_server_files FROM regress_pg_walinspect; |
||||
|
||||
-- Superuser can grant execute to other users |
||||
GRANT EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) |
||||
TO regress_pg_walinspect; |
||||
|
||||
GRANT EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) |
||||
TO regress_pg_walinspect; |
||||
|
||||
GRANT EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean) |
||||
TO regress_pg_walinspect; |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_record_info(pg_lsn)', 'EXECUTE'); -- yes |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_records_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- yes |
||||
|
||||
SELECT has_function_privilege('regress_pg_walinspect', |
||||
'pg_get_wal_stats(pg_lsn, pg_lsn, boolean) ', 'EXECUTE'); -- yes |
||||
|
||||
REVOKE EXECUTE ON FUNCTION pg_get_wal_record_info(pg_lsn) |
||||
FROM regress_pg_walinspect; |
||||
|
||||
REVOKE EXECUTE ON FUNCTION pg_get_wal_records_info(pg_lsn, pg_lsn) |
||||
FROM regress_pg_walinspect; |
||||
|
||||
REVOKE EXECUTE ON FUNCTION pg_get_wal_stats(pg_lsn, pg_lsn, boolean) |
||||
FROM regress_pg_walinspect; |
||||
|
||||
-- =================================================================== |
||||
-- Clean up |
||||
-- =================================================================== |
||||
|
||||
DROP ROLE regress_pg_walinspect; |
||||
|
||||
SELECT pg_drop_replication_slot('regress_pg_walinspect_slot'); |
||||
|
||||
DROP TABLE sample_tbl; |
||||
@ -0,0 +1,275 @@ |
||||
<!-- doc/src/sgml/pgwalinspect.sgml --> |
||||
|
||||
<sect1 id="pgwalinspect" xreflabel="pg_walinspect"> |
||||
<title>pg_walinspect</title> |
||||
|
||||
<indexterm zone="pgwalinspect"> |
||||
<primary>pg_walinspect</primary> |
||||
</indexterm> |
||||
|
||||
<para> |
||||
The <filename>pg_walinspect</filename> module provides SQL functions that |
||||
allow you to inspect the contents of write-ahead log of |
||||
a running <productname>PostgreSQL</productname> database cluster at a low |
||||
level, which is useful for debugging or analytical or reporting or |
||||
educational purposes. It is similar to <xref linkend="pgwaldump"/>, but |
||||
accessible through SQL rather than a separate utility. |
||||
</para> |
||||
|
||||
<para> |
||||
All the functions of this module will provide the WAL information using the |
||||
current server's timeline ID. |
||||
</para> |
||||
|
||||
<para> |
||||
All the functions of this module will try to find the first valid WAL record |
||||
that is at or after the given <replaceable>in_lsn</replaceable> or |
||||
<replaceable>start_lsn</replaceable> and will emit error if no such record |
||||
is available. Similarly, the <replaceable>end_lsn</replaceable> must be |
||||
available, and if it falls in the middle of a record, the entire record must |
||||
be available. |
||||
</para> |
||||
|
||||
<note> |
||||
<para> |
||||
Some functions, such as <function><link |
||||
linkend="pg-logical-emit-message">pg_logical_emit_message</link></function>, |
||||
return the LSN <emphasis>after</emphasis> the record just |
||||
inserted. Therefore, if you pass that LSN as |
||||
<replaceable>in_lsn</replaceable> or <replaceable>start_lsn</replaceable> |
||||
to one of these functions, it will return the <emphasis>next</emphasis> |
||||
record. |
||||
</para> |
||||
</note> |
||||
<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> |
||||
<title>General Functions</title> |
||||
|
||||
<variablelist> |
||||
<varlistentry> |
||||
<term> |
||||
<function> |
||||
pg_get_wal_record_info(in_lsn pg_lsn, |
||||
start_lsn OUT pg_lsn, |
||||
end_lsn OUT pg_lsn, |
||||
prev_lsn OUT pg_lsn, |
||||
xid OUT xid, |
||||
resource_manager OUT text, |
||||
record_type OUT text, |
||||
record_length OUT int4, |
||||
main_data_length OUT int4, |
||||
fpi_length OUT int4, |
||||
description OUT text, |
||||
block_ref OUT text) |
||||
</function> |
||||
</term> |
||||
|
||||
<listitem> |
||||
<para> |
||||
Gets WAL record information of a given LSN. If the given LSN isn't |
||||
at the start of a WAL record, it gives the information of the next |
||||
available valid WAL record; or an error if no such record is found. |
||||
</para> |
||||
</listitem> |
||||
</varlistentry> |
||||
|
||||
<varlistentry> |
||||
<term> |
||||
<function> |
||||
pg_get_wal_records_info(start_lsn pg_lsn, |
||||
end_lsn pg_lsn, |
||||
start_lsn OUT pg_lsn, |
||||
end_lsn OUT pg_lsn, |
||||
prev_lsn OUT pg_lsn, |
||||
xid OUT xid, |
||||
resource_manager OUT text, |
||||
record_type OUT text, |
||||
record_length OUT int4, |
||||
main_data_length OUT int4, |
||||
fpi_length OUT int4, |
||||
description OUT text, |
||||
block_ref OUT text) |
||||
returns setof record |
||||
</function> |
||||
</term> |
||||
|
||||
<listitem> |
||||
<para> |
||||
Gets information of all the valid WAL records between |
||||
<replaceable>start_lsn</replaceable> and <replaceable>end_lsn</replaceable>. |
||||
Returns one row per WAL record. If <replaceable>start_lsn</replaceable> |
||||
or <replaceable>end_lsn</replaceable> are not yet available, the |
||||
function will raise an error. For example, usage of the function is as |
||||
follows: |
||||
<screen> |
||||
postgres=# select start_lsn, end_lsn, prev_lsn, xid, resource_manager, record_type, record_length, main_data_length, fpi_length, description from pg_get_wal_records_info('0/14F9A30', '0/15011D7'); |
||||
start_lsn | end_lsn | prev_lsn | xid | resource_manager | record_type | record_length | main_data_length | fpi_length | description |
||||
-----------+-----------+-----------+-----+------------------+--------------+---------------+------------------+------------+--------------------- |
||||
0/14FA118 | 0/14FB4B0 | 0/14F9958 | 725 | Btree | INSERT_LEAF | 5013 | 2 | 4960 | off 246 |
||||
0/14FB4B0 | 0/14FD050 | 0/14FA118 | 725 | Btree | INSERT_LEAF | 7045 | 2 | 6992 | off 130 |
||||
0/14FD050 | 0/14FD0A8 | 0/14FB4B0 | 725 | Heap2 | MULTI_INSERT | 85 | 6 | 0 | 1 tuples flags 0x02 |
||||
0/14FD0A8 | 0/14FD0F0 | 0/14FD050 | 725 | Btree | INSERT_LEAF | 72 | 2 | 0 | off 155 |
||||
0/14FD0F0 | 0/14FD138 | 0/14FD0A8 | 725 | Btree | INSERT_LEAF | 72 | 2 | 0 | off 134 |
||||
0/14FD138 | 0/14FD210 | 0/14FD0F0 | 725 | Heap | INSERT | 211 | 3 | 0 | off 11 flags 0x00 |
||||
0/14FD210 | 0/14FD250 | 0/14FD138 | 725 | Btree | INSERT_LEAF | 64 | 2 | 0 | off 246 |
||||
0/14FD250 | 0/14FF260 | 0/14FD210 | 725 | Btree | INSERT_LEAF | 8181 | 2 | 8128 | off 47 |
||||
0/14FF260 | 0/14FF2B8 | 0/14FD250 | 725 | Heap2 | MULTI_INSERT | 85 | 6 | 0 | 1 tuples flags 0x02 |
||||
0/14FF2B8 | 0/14FF300 | 0/14FF260 | 725 | Btree | INSERT_LEAF | 72 | 2 | 0 | off 155 |
||||
0/14FF300 | 0/15008D8 | 0/14FF2B8 | 725 | Btree | INSERT_LEAF | 5565 | 2 | 5512 | off 106 |
||||
0/15008D8 | 0/1500C48 | 0/14FF300 | 725 | Heap | INSERT | 874 | 3 | 820 | off 2 flags 0x01 |
||||
(12 rows) |
||||
</screen> |
||||
</para> |
||||
</listitem> |
||||
</varlistentry> |
||||
|
||||
<varlistentry> |
||||
<term> |
||||
<function> |
||||
pg_get_wal_records_info_till_end_of_wal(start_lsn pg_lsn, |
||||
start_lsn OUT pg_lsn, |
||||
end_lsn OUT pg_lsn, |
||||
prev_lsn OUT pg_lsn, |
||||
xid OUT xid, |
||||
resource_manager OUT text, |
||||
record_type OUT text, |
||||
record_length OUT int4, |
||||
main_data_length OUT int4, |
||||
fpi_length OUT int4, |
||||
description OUT text, |
||||
block_ref OUT text) |
||||
returns setof record |
||||
</function> |
||||
</term> |
||||
|
||||
<listitem> |
||||
<para> |
||||
This function is same as <function>pg_get_wal_records_info()</function> |
||||
except that it gets information of all the valid WAL records from |
||||
<replaceable>start_lsn</replaceable> till the end of WAL. |
||||
</para> |
||||
</listitem> |
||||
</varlistentry> |
||||
|
||||
<varlistentry> |
||||
<term> |
||||
<function> |
||||
pg_get_wal_stats(start_lsn pg_lsn, |
||||
end_lsn pg_lsn, |
||||
per_record boolean DEFAULT false, |
||||
"resource_manager/record_type" OUT text, |
||||
count OUT int8, |
||||
count_percentage OUT float4, |
||||
record_length OUT int8, |
||||
record_length_percentage OUT float4, |
||||
fpi_length OUT int8, |
||||
fpi_length_percentage OUT float4, |
||||
combined_size OUT int8, |
||||
combined_size_percentage OUT float4) |
||||
returns setof record |
||||
</function> |
||||
</term> |
||||
|
||||
<listitem> |
||||
<para> |
||||
Gets statistics of all the valid WAL records between |
||||
<replaceable>start_lsn</replaceable> and |
||||
<replaceable>end_lsn</replaceable>. By default, it returns one row per |
||||
<replaceable>resource_manager</replaceable> type. When |
||||
<replaceable>per_record</replaceable> is set to <literal>true</literal>, |
||||
it returns one row per <replaceable>record_type</replaceable>. |
||||
If <replaceable>start_lsn</replaceable> |
||||
or <replaceable>end_lsn</replaceable> are not yet available, the |
||||
function will raise an error. For example, usage of the function is as |
||||
follows: |
||||
<screen> |
||||
postgres=# select * from pg_get_wal_stats('0/12FBA30', '0/15011D7') where count > 0; |
||||
resource_manager/record_type | count | count_percentage | record_size | record_size_percentage | fpi_size | fpi_size_percentage | combined_size | combined_size_percentage |
||||
------------------------------+-------+------------------+-------------+------------------------+----------+---------------------+---------------+-------------------------- |
||||
XLOG | 10 | 0.10871929 | 796 | 0.052369177 | 352 | 0.061031006 | 1148 | 0.054751817 |
||||
Transaction | 187 | 2.0330508 | 62773 | 4.1298623 | 0 | 0 | 62773 | 2.9938467 |
||||
Storage | 13 | 0.14133507 | 546 | 0.035921574 | 0 | 0 | 546 | 0.0260405 |
||||
Database | 2 | 0.021743858 | 84 | 0.005526396 | 0 | 0 | 84 | 0.0040062307 |
||||
Standby | 218 | 2.3700805 | 15908 | 1.0465941 | 0 | 0 | 15908 | 0.75870377 |
||||
Heap2 | 1897 | 20.624048 | 383916 | 25.257998 | 364472 | 63.193447 | 748388 | 35.693035 |
||||
Heap | 1318 | 14.329202 | 621390 | 40.88151 | 139660 | 24.214746 | 761050 | 36.29693 |
||||
Btree | 5553 | 60.37182 | 434565 | 28.590216 | 72272 | 12.530776 | 506837 | 24.17269 |
||||
(8 rows) |
||||
</screen> |
||||
|
||||
With <replaceable>per_record</replaceable> passed as <literal>true</literal>: |
||||
|
||||
<screen> |
||||
postgres=# select * from pg_get_wal_stats('0/14AFC30', '0/15011D7', true) where count > 0; |
||||
resource_manager/record_type | count | count_percentage | record_size | record_size_percentage | fpi_size | fpi_size_percentage | combined_size | combined_size_percentage |
||||
------------------------------+-------+------------------+-------------+------------------------+----------+---------------------+---------------+-------------------------- |
||||
XLOG/CHECKPOINT_SHUTDOWN | 1 | 0.32894737 | 114 | 0.22891566 | 0 | 0 | 114 | 0.03534489 |
||||
XLOG/CHECKPOINT_ONLINE | 4 | 1.3157895 | 456 | 0.91566265 | 0 | 0 | 456 | 0.14137957 |
||||
XLOG/NEXTOID | 1 | 0.32894737 | 30 | 0.060240965 | 0 | 0 | 30 | 0.009301287 |
||||
Transaction/COMMIT | 9 | 2.9605262 | 1173 | 2.3554218 | 0 | 0 | 1173 | 0.36368033 |
||||
Storage/CREATE | 1 | 0.32894737 | 42 | 0.084337346 | 0 | 0 | 42 | 0.0130218025 |
||||
Database/CREATE_FILE_COPY | 2 | 0.65789473 | 84 | 0.16867469 | 0 | 0 | 84 | 0.026043605 |
||||
Standby/RUNNING_XACTS | 6 | 1.9736842 | 316 | 0.6345382 | 0 | 0 | 316 | 0.09797356 |
||||
Standby/INVALIDATIONS | 45 | 14.802631 | 4018 | 8.068274 | 0 | 0 | 4018 | 1.2457525 |
||||
Heap2/PRUNE | 4 | 1.3157895 | 270 | 0.5421687 | 0 | 0 | 270 | 0.08371159 |
||||
Heap2/FREEZE_PAGE | 27 | 8.881579 | 20904 | 41.975903 | 0 | 0 | 20904 | 6.481137 |
||||
Heap2/VISIBLE | 29 | 9.539474 | 1756 | 3.5261045 | 73728 | 27.032736 | 75484 | 23.403278 |
||||
Heap2/MULTI_INSERT | 13 | 4.2763157 | 1049 | 2.1064258 | 12216 | 4.479057 | 13265 | 4.112719 |
||||
Heap/INSERT | 19 | 6.25 | 2324 | 4.6666665 | 43884 | 16.090284 | 46208 | 14.326463 |
||||
Heap/UPDATE | 7 | 2.3026316 | 511 | 1.0261045 | 54340 | 19.924028 | 54851 | 17.006165 |
||||
Heap/HOT_UPDATE | 11 | 3.618421 | 1134 | 2.2771084 | 468 | 0.17159452 | 1602 | 0.49668875 |
||||
Heap/LOCK | 8 | 2.631579 | 432 | 0.8674699 | 0 | 0 | 432 | 0.13393854 |
||||
Heap/INPLACE | 45 | 14.802631 | 9123 | 18.319277 | 16076 | 5.894345 | 25199 | 7.8127713 |
||||
Heap/UPDATE+INIT | 1 | 0.32894737 | 817 | 1.6405623 | 0 | 0 | 817 | 0.25330505 |
||||
Btree/INSERT_LEAF | 70 | 23.026316 | 5183 | 10.407631 | 72024 | 26.407955 | 77207 | 23.937483 |
||||
Btree/DEDUP | 1 | 0.32894737 | 64 | 0.12851405 | 0 | 0 | 64 | 0.019842746 |
||||
(20 rows) |
||||
</screen> |
||||
</para> |
||||
</listitem> |
||||
</varlistentry> |
||||
|
||||
<varlistentry> |
||||
<term> |
||||
<function> |
||||
pg_get_wal_stats_till_end_of_wal(start_lsn pg_lsn, |
||||
per_record boolean DEFAULT false, |
||||
"resource_manager/record_type" OUT text, |
||||
count OUT int8, |
||||
count_percentage OUT float4, |
||||
record_length OUT int8, |
||||
record_length_percentage OUT float4, |
||||
fpi_length OUT int8, |
||||
fpi_length_percentage OUT float4, |
||||
combined_size OUT int8, |
||||
combined_size_percentage OUT float4) |
||||
returns setof record |
||||
</function> |
||||
</term> |
||||
|
||||
<listitem> |
||||
<para> |
||||
This function is same as <function>pg_get_wal_stats()</function> except |
||||
that it gets statistics of all the valid WAL records from |
||||
<replaceable>start_lsn</replaceable> till end of WAL. |
||||
</para> |
||||
</listitem> |
||||
</varlistentry> |
||||
|
||||
</variablelist> |
||||
</sect2> |
||||
|
||||
<sect2> |
||||
<title>Author</title> |
||||
|
||||
<para> |
||||
Bharath Rupireddy <email>bharath.rupireddyforpostgres@gmail.com</email> |
||||
</para> |
||||
</sect2> |
||||
|
||||
</sect1> |
||||
@ -0,0 +1,93 @@ |
||||
/*-------------------------------------------------------------------------
|
||||
* |
||||
* xlogstats.c |
||||
* Functions for WAL Statitstics |
||||
* |
||||
* Copyright (c) 2022, PostgreSQL Global Development Group |
||||
* |
||||
* IDENTIFICATION |
||||
* src/backend/access/transam/xlogstats.c |
||||
* |
||||
*------------------------------------------------------------------------- |
||||
*/ |
||||
#include "postgres.h" |
||||
|
||||
#include "access/xlogreader.h" |
||||
#include "access/xlogstats.h" |
||||
|
||||
/*
|
||||
* Calculate the size of a record, split into !FPI and FPI parts. |
||||
*/ |
||||
void |
||||
XLogRecGetLen(XLogReaderState *record, uint32 *rec_len, |
||||
uint32 *fpi_len) |
||||
{ |
||||
int block_id; |
||||
|
||||
/*
|
||||
* Calculate the amount of FPI data in the record. |
||||
* |
||||
* XXX: We peek into xlogreader's private decoded backup blocks for the |
||||
* bimg_len indicating the length of FPI data. |
||||
*/ |
||||
*fpi_len = 0; |
||||
for (block_id = 0; block_id <= XLogRecMaxBlockId(record); block_id++) |
||||
{ |
||||
if (XLogRecHasBlockImage(record, block_id)) |
||||
*fpi_len += XLogRecGetBlock(record, block_id)->bimg_len; |
||||
} |
||||
|
||||
/*
|
||||
* Calculate the length of the record as the total length - the length of |
||||
* all the block images. |
||||
*/ |
||||
*rec_len = XLogRecGetTotalLen(record) - *fpi_len; |
||||
} |
||||
|
||||
/*
|
||||
* Store per-rmgr and per-record statistics for a given record. |
||||
*/ |
||||
void |
||||
XLogRecStoreStats(XLogStats *stats, XLogReaderState *record) |
||||
{ |
||||
RmgrId rmid; |
||||
uint8 recid; |
||||
uint32 rec_len; |
||||
uint32 fpi_len; |
||||
|
||||
Assert(stats != NULL && record != NULL); |
||||
|
||||
stats->count++; |
||||
|
||||
rmid = XLogRecGetRmid(record); |
||||
|
||||
XLogRecGetLen(record, &rec_len, &fpi_len); |
||||
|
||||
/* Update per-rmgr statistics */ |
||||
|
||||
stats->rmgr_stats[rmid].count++; |
||||
stats->rmgr_stats[rmid].rec_len += rec_len; |
||||
stats->rmgr_stats[rmid].fpi_len += fpi_len; |
||||
|
||||
/*
|
||||
* Update per-record statistics, where the record is identified by a |
||||
* combination of the RmgrId and the four bits of the xl_info field that |
||||
* are the rmgr's domain (resulting in sixteen possible entries per |
||||
* RmgrId). |
||||
*/ |
||||
|
||||
recid = XLogRecGetInfo(record) >> 4; |
||||
|
||||
/*
|
||||
* XACT records need to be handled differently. Those records use the |
||||
* first bit of those four bits for an optional flag variable and the |
||||
* following three bits for the opcode. We filter opcode out of xl_info |
||||
* and use it as the identifier of the record. |
||||
*/ |
||||
if (rmid == RM_XACT_ID) |
||||
recid &= 0x07; |
||||
|
||||
stats->record_stats[rmid][recid].count++; |
||||
stats->record_stats[rmid][recid].rec_len += rec_len; |
||||
stats->record_stats[rmid][recid].fpi_len += fpi_len; |
||||
} |
||||
@ -0,0 +1,40 @@ |
||||
/*-------------------------------------------------------------------------
|
||||
* |
||||
* xlogstats.h |
||||
* Definitions for WAL Statitstics |
||||
* |
||||
* Copyright (c) 2022, PostgreSQL Global Development Group |
||||
* |
||||
* IDENTIFICATION |
||||
* src/include/access/xlogstats.h |
||||
* |
||||
*------------------------------------------------------------------------- |
||||
*/ |
||||
#ifndef XLOGSTATS_H |
||||
#define XLOGSTATS_H |
||||
|
||||
#define MAX_XLINFO_TYPES 16 |
||||
|
||||
typedef struct XLogRecStats |
||||
{ |
||||
uint64 count; |
||||
uint64 rec_len; |
||||
uint64 fpi_len; |
||||
} XLogRecStats; |
||||
|
||||
typedef struct XLogStats |
||||
{ |
||||
uint64 count; |
||||
#ifdef FRONTEND |
||||
XLogRecPtr startptr; |
||||
XLogRecPtr endptr; |
||||
#endif |
||||
XLogRecStats rmgr_stats[RM_MAX_ID + 1]; |
||||
XLogRecStats record_stats[RM_MAX_ID + 1][MAX_XLINFO_TYPES]; |
||||
} XLogStats; |
||||
|
||||
extern void XLogRecGetLen(XLogReaderState *record, uint32 *rec_len, |
||||
uint32 *fpi_len); |
||||
extern void XLogRecStoreStats(XLogStats *stats, XLogReaderState *record); |
||||
|
||||
#endif /* XLOGSTATS_H */ |
||||
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Reference in new issue