Prevent instability in contrib/pageinspect's regression test.

tglsfdc · tglsfdc · commit e2933a6e1179 · 2022-11-21T10:50:50.000-05:00
pageinspect has occasionally failed on slow buildfarm members, with symptoms indicating that the expected effects of VACUUM FREEZE didn't happen. This is presumably because a background transaction such as auto-analyze was holding back global xmin. We can work around that by using a temp table in the test. Since commit a7212be, that will use an up-to-date cutoff xmin regardless of other processes. And pageinspect itself shouldn't really care whether the table is temp. Back-patch to v14. There would be no point in older branches without back-patching a7212be, which seems like more trouble than the problem is worth. Discussion: https://postgr.es/m/2892135.1668976646@sss.pgh.pa.us
diff --git a/contrib/pageinspect/expected/page.out b/contrib/pageinspect/expected/page.out
@@ -1,5 +1,6 @@
 CREATE EXTENSION pageinspect;
-CREATE TABLE test1 (a int, b int);
+-- Use a temp table so that effects of VACUUM are predictable
+CREATE TEMP TABLE test1 (a int, b int);
 INSERT INTO test1 VALUES (16777217, 131584);
 VACUUM (DISABLE_PAGE_SKIPPING) test1;  -- set up FSM
 -- The page contents can vary, so just test that it can be read
diff --git a/contrib/pageinspect/sql/page.sql b/contrib/pageinspect/sql/page.sql
@@ -1,6 +1,7 @@
 CREATE EXTENSION pageinspect;
 
-CREATE TABLE test1 (a int, b int);
+-- Use a temp table so that effects of VACUUM are predictable
+CREATE TEMP TABLE test1 (a int, b int);
 INSERT INTO test1 VALUES (16777217, 131584);
 
 VACUUM (DISABLE_PAGE_SKIPPING) test1;  -- set up FSM
