Rearrange core regression tests to reduce cross-script dependencies.

The idea behind this patch is to make it possible to run individual
test scripts without running the entire core test suite.  Making all
the scripts completely independent would involve a massive rewrite,
and would probably be worse for coverage of things like concurrent DDL.
So this patch just does what seems practical with limited changes.

The net effect is that any test script can be run after running
limited earlier dependencies:
* all scripts depend on test_setup
* many scripts depend on create_index
* other dependencies are few in number, and are documented in
  the parallel_schedule file.

To accomplish this, I chose a small number of commonly-used tables
and moved their creation and filling into test_setup.  Later scripts
are expected not to modify these tables' data contents, for fear of
affecting other scripts' results.  Also, our former habit of declaring
all C functions in one place is now gone in favor of declaring them
where they're used, if that's just one script, or in test_setup if
necessary.

There's more that could be done to remove some of the remaining
inter-script dependencies, but significantly more-invasive changes
would be needed, and at least for now it doesn't seem worth it.

Discussion: https://postgr.es/m/1114748.1640383217@sss.pgh.pa.us

1 files changed, 17 insertions, 0 deletions

diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 3ab7f392be4..f774faf8568 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -2,6 +2,9 @@
 -- ARRAYS
 --
 
+-- directory paths are passed to us in environment variables
+\getenv abs_srcdir PG_ABS_SRCDIR
+
 CREATE TABLE arrtest (
 	a 			int2[],
 	b 			int4[][][],
@@ -12,6 +15,16 @@ CREATE TABLE arrtest (
 	g			varchar(5)[]
 );
 
+CREATE TABLE array_op_test (
+	seqno		int4,
+	i			int4[],
+	t			text[]
+);
+
+\set filename :abs_srcdir '/data/array.data'
+COPY array_op_test FROM :'filename';
+ANALYZE array_op_test;
+
 --
 -- only the 'e' array is 0-based, the others are 1-based.
 --
@@ -153,6 +166,10 @@ UPDATE arrtest_s SET a[:] = '{23, 24, 25}';  -- fail, too small
 INSERT INTO arrtest_s VALUES(NULL, NULL);
 UPDATE arrtest_s SET a[:] = '{11, 12, 13, 14, 15}';  -- fail, no good with null
 
+-- we want to work with a point_tbl that includes a null
+CREATE TEMP TABLE point_tbl AS SELECT * FROM public.point_tbl;
+INSERT INTO POINT_TBL(f1) VALUES (NULL);
+
 -- check with fixed-length-array type, such as point
 SELECT f1[0:1] FROM POINT_TBL;
 SELECT f1[0:] FROM POINT_TBL;