Improve a bit the tests of pg_walinspect

This commit improves the tests of pg_walinspect on a few things:
- Remove aggregates for queries that should fail.  If the code is
reworked in such a way that the behavior of these queries is changed,
we would get more input from them, written this way.
- Expect at least one record reported in the valid queries doing scans
across ranges, rather than zero records.
- Adjust a few comments, for consistency.

Author: Bharath Rupireddy
Discussion: https://postgr.es/m/CALj2ACVaoXW3nJD9zq8E66BEf-phgJfFcKRVJq9GXkuX0b3ULQ@mail.gmail.com

contrib/pg_walinspect/expected/oldextversions.out

@@ -1,4 +1,4 @@
--- test old extension version entry points
+-- Test old extension version entry points.
 CREATE EXTENSION pg_walinspect WITH VERSION '1.0';
 -- Mask DETAIL messages as these could refer to current LSN positions.
 \set VERBOSITY terse
@@ -28,7 +28,7 @@ SELECT 'init' FROM pg_create_physical_replication_slot('regress_pg_walinspect_sl
 CREATE TABLE sample_tbl(col1 int, col2 int);
 SELECT pg_current_wal_lsn() AS wal_lsn1 \gset
 INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2);
--- Check bounds for these past functions.
+-- Tests for the past functions.
 SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info_till_end_of_wal(:'wal_lsn1');
  ok 
 ----
@@ -41,13 +41,14 @@ SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats_till_end_of_wal(:'wal_lsn1');
  t
 (1 row)
 
-SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info_till_end_of_wal('FFFFFFFF/FFFFFFFF');
+-- Failures with start LSNs.
+SELECT * FROM pg_get_wal_records_info_till_end_of_wal('FFFFFFFF/FFFFFFFF');
 ERROR:  WAL start LSN must be less than current LSN
-SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats_till_end_of_wal('FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_stats_till_end_of_wal('FFFFFFFF/FFFFFFFF');
 ERROR:  WAL start LSN must be less than current LSN
--- Move to new version 1.1
+-- Move to new version 1.1.
 ALTER EXTENSION pg_walinspect UPDATE TO '1.1';
--- List what version 1.1 contains
+-- List what version 1.1 contains.
 \dx+ pg_walinspect
        Objects in extension "pg_walinspect"
                 Object description                

contrib/pg_walinspect/expected/pg_walinspect.out

@@ -9,7 +9,7 @@ SELECT 'init' FROM pg_create_physical_replication_slot('regress_pg_walinspect_sl
 (1 row)
 
 CREATE TABLE sample_tbl(col1 int, col2 int);
--- Save some LSNs for comparisons
+-- Save some LSNs for comparisons.
 SELECT pg_current_wal_lsn() AS wal_lsn1 \gset
 INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2);
 SELECT pg_current_wal_lsn() AS wal_lsn2 \gset
@@ -35,56 +35,56 @@ ERROR:  WAL start LSN must be less than end LSN
 SELECT * FROM pg_get_wal_block_info(:'wal_lsn2', :'wal_lsn1');
 ERROR:  WAL start LSN must be less than end LSN
 -- LSNs with the highest value possible.
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_record_info('FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_record_info('FFFFFFFF/FFFFFFFF');
 ERROR:  WAL input LSN must be less than current LSN
 -- Success with end LSNs.
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
  ok 
 ----
  t
 (1 row)
 
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
  ok 
 ----
  t
 (1 row)
 
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
  ok 
 ----
  t
 (1 row)
 
--- failures with start LSNs
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+-- Failures with start LSNs.
+SELECT * FROM pg_get_wal_records_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
 ERROR:  WAL start LSN must be less than current LSN
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_stats('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
 ERROR:  WAL start LSN must be less than current LSN
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_block_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
 ERROR:  WAL start LSN must be less than current LSN
 -- ===================================================================
 -- Tests for all function executions
 -- ===================================================================
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_record_info(:'wal_lsn1');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_record_info(:'wal_lsn1');
  ok 
 ----
  t
 (1 row)
 
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2');
  ok 
 ----
  t
 (1 row)
 
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2');
  ok 
 ----
  t
 (1 row)
 
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', :'wal_lsn2');
  ok 
 ----
  t
@@ -115,7 +115,7 @@ SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2'
 -- ===================================================================
 -- Tests to get block information from WAL record
 -- ===================================================================
--- Update table to generate some block data
+-- Update table to generate some block data.
 SELECT pg_current_wal_lsn() AS wal_lsn3 \gset
 UPDATE sample_tbl SET col1 = col1 + 1 WHERE col1 = 1;
 SELECT pg_current_wal_lsn() AS wal_lsn4 \gset
@@ -172,7 +172,7 @@ SELECT has_function_privilege('regress_pg_walinspect',
  f
 (1 row)
 
--- Functions accessible by users with role pg_read_server_files
+-- 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
@@ -203,7 +203,7 @@ SELECT has_function_privilege('regress_pg_walinspect',
 (1 row)
 
 REVOKE pg_read_server_files FROM regress_pg_walinspect;
--- Superuser can grant execute to other users
+-- 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)

contrib/pg_walinspect/sql/oldextversions.sql

@@ -1,4 +1,4 @@
--- test old extension version entry points
+-- Test old extension version entry points.
 
 CREATE EXTENSION pg_walinspect WITH VERSION '1.0';
 
@@ -20,16 +20,17 @@ CREATE TABLE sample_tbl(col1 int, col2 int);
 SELECT pg_current_wal_lsn() AS wal_lsn1 \gset
 INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2);
 
--- Check bounds for these past functions.
+-- Tests for the past functions.
 SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info_till_end_of_wal(:'wal_lsn1');
 SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats_till_end_of_wal(:'wal_lsn1');
-SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info_till_end_of_wal('FFFFFFFF/FFFFFFFF');
-SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats_till_end_of_wal('FFFFFFFF/FFFFFFFF');
+-- Failures with start LSNs.
+SELECT * FROM pg_get_wal_records_info_till_end_of_wal('FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_stats_till_end_of_wal('FFFFFFFF/FFFFFFFF');
 
--- Move to new version 1.1
+-- Move to new version 1.1.
 ALTER EXTENSION pg_walinspect UPDATE TO '1.1';
 
--- List what version 1.1 contains
+-- List what version 1.1 contains.
 \dx+ pg_walinspect
 
 SELECT pg_drop_replication_slot('regress_pg_walinspect_slot');

contrib/pg_walinspect/sql/pg_walinspect.sql

@@ -8,7 +8,7 @@ SELECT 'init' FROM pg_create_physical_replication_slot('regress_pg_walinspect_sl
 
 CREATE TABLE sample_tbl(col1 int, col2 int);
 
--- Save some LSNs for comparisons
+-- Save some LSNs for comparisons.
 SELECT pg_current_wal_lsn() AS wal_lsn1 \gset
 INSERT INTO sample_tbl SELECT * FROM generate_series(1, 2);
 SELECT pg_current_wal_lsn() AS wal_lsn2 \gset
@@ -32,24 +32,24 @@ SELECT * FROM pg_get_wal_stats(:'wal_lsn2', :'wal_lsn1');
 SELECT * FROM pg_get_wal_block_info(:'wal_lsn2', :'wal_lsn1');
 
 -- LSNs with the highest value possible.
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_record_info('FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_record_info('FFFFFFFF/FFFFFFFF');
 -- Success with end LSNs.
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
--- failures with start LSNs
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_records_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_stats('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', 'FFFFFFFF/FFFFFFFF');
+-- Failures with start LSNs.
+SELECT * FROM pg_get_wal_records_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_stats('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
+SELECT * FROM pg_get_wal_block_info('FFFFFFFF/FFFFFFFE', 'FFFFFFFF/FFFFFFFF');
 
 -- ===================================================================
 -- 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_stats(:'wal_lsn1', :'wal_lsn2');
-SELECT COUNT(*) >= 0 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_record_info(:'wal_lsn1');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_stats(:'wal_lsn1', :'wal_lsn2');
+SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_block_info(:'wal_lsn1', :'wal_lsn2');
 
 -- ===================================================================
 -- Test for filtering out WAL records of a particular table
@@ -72,7 +72,7 @@ SELECT COUNT(*) >= 1 AS ok FROM pg_get_wal_records_info(:'wal_lsn1', :'wal_lsn2'
 -- Tests to get block information from WAL record
 -- ===================================================================
 
--- Update table to generate some block data
+-- Update table to generate some block data.
 SELECT pg_current_wal_lsn() AS wal_lsn3 \gset
 UPDATE sample_tbl SET col1 = col1 + 1 WHERE col1 = 1;
 SELECT pg_current_wal_lsn() AS wal_lsn4 \gset
@@ -103,9 +103,9 @@ SELECT has_function_privilege('regress_pg_walinspect',
 SELECT has_function_privilege('regress_pg_walinspect',
   'pg_get_wal_block_info(pg_lsn, pg_lsn) ', 'EXECUTE'); -- no
 
--- Functions accessible by users with role pg_read_server_files
-
+-- 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',
@@ -117,7 +117,7 @@ SELECT has_function_privilege('regress_pg_walinspect',
 
 REVOKE pg_read_server_files FROM regress_pg_walinspect;
 
--- Superuser can grant execute to other users
+-- 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)