Add better regression tests

.gitignore

@@ -1,3 +1,6 @@
+results/*
+regression.diffs
+regression.out
 *.gcno
 *.o
 *.so

expected/simple.out

@@ -1,6 +1,68 @@
-SELECT 1
- ?column? 
-----------
-        1
+CREATE EXTENSION yezzey;
+-- AO
+CREATE TABLE regaoty(i INT) WITH (appendonly=true);
+NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause -- Using column named 'i' as the Greenplum Database data distribution key for this table.
+HINT:  The 'DISTRIBUTED BY' clause determines the distribution of data. Make sure column(s) chosen are the optimal data distribution key to minimize skew.
+INSERT INTO regaoty SELECT * FROM generate_series(1, 100000);
+SELECT * FROM yezzey_define_offload_policy('regaoty');
+NOTICE:  yezzey: relation virtual size calculated: 0  (seg0 slice1 127.0.1.1:6002 pid=1819226)
+NOTICE:  yezzey: relation virtual size calculated: 0  (seg1 slice1 127.0.1.1:6003 pid=1819227)
+NOTICE:  yezzey: relation virtual size calculated: 0  (seg2 slice1 127.0.1.1:6004 pid=1819228)
+INFO:  yezzey: relation segment reached external storage (blkno=1), up to logical eof 335168  (seg0 slice1 127.0.1.1:6002 pid=1819226)
+INFO:  yezzey: relation segment reached external storage (blkno=1), up to logical eof 333816  (seg1 slice1 127.0.1.1:6003 pid=1819227)
+INFO:  yezzey: relation segment reached external storage (blkno=1), up to logical eof 332656  (seg2 slice1 127.0.1.1:6004 pid=1819228)
+ yezzey_define_offload_policy 
+------------------------------
+
 (1 row)
 
+SELECT count(1) FROM yezzey_dump_virtual_index('regaoty');
+ count 
+-------
+     3
+(1 row)
+
+INSERT INTO regaoty SELECT * FROM generate_series(1, 100000);
+SELECT count(1) FROM regaoty;
+ count  
+--------
+ 200000
+(1 row)
+
+SELECT * FROM regaoty ORDER BY i LIMIT 5 OFFSET 7823;
+  i   
+------
+ 3912
+ 3913
+ 3913
+ 3914
+ 3914
+(5 rows)
+
+SELECT segindex,external_bytes FROM yezzey_offload_relation_status('regaoty');
+ segindex | external_bytes 
+----------+----------------
+        0 |         670336
+        1 |         667632
+        2 |         665312
+(3 rows)
+
+SELECT segindex,segfileindex,external_bytes FROM yezzey_offload_relation_status_per_filesegment('regaoty');
+ segindex | segfileindex | external_bytes 
+----------+--------------+----------------
+        2 |            1 |         665312
+        1 |            1 |         667632
+        0 |            1 |         670336
+(3 rows)
+
+SELECT segindex,segfileindex,external_bytes FROM yezzey_relation_describe_external_storage_structure('regaoty');
+ segindex | segfileindex | external_bytes 
+----------+--------------+----------------
+        0 |            1 |         335168
+        0 |            1 |         335168
+        1 |            1 |         333816
+        1 |            1 |         333816
+        2 |            1 |         332656
+        2 |            1 |         332656
+(6 rows)
+

sql/simple.sql

@@ -1 +1,21 @@
-SELECT 1
+
+CREATE EXTENSION yezzey;
+
+-- AO
+
+CREATE TABLE regaoty(i INT) WITH (appendonly=true);
+INSERT INTO regaoty SELECT * FROM generate_series(1, 100000);
+SELECT * FROM yezzey_define_offload_policy('regaoty');
+
+SELECT count(1) FROM yezzey_dump_virtual_index('regaoty');
+
+INSERT INTO regaoty SELECT * FROM generate_series(1, 100000);
+
+SELECT count(1) FROM regaoty;
+
+SELECT * FROM regaoty ORDER BY i LIMIT 5 OFFSET 7823;
+
+SELECT segindex,external_bytes FROM yezzey_offload_relation_status('regaoty');
+SELECT segindex,segfileindex,external_bytes FROM yezzey_offload_relation_status_per_filesegment('regaoty');
+SELECT segindex,segfileindex,external_bytes FROM yezzey_relation_describe_external_storage_structure('regaoty');
+