plancache.out

来自「postgresql8.3.4源码,开源数据库」· OUT 代码 · 共 262 行

--
-- Tests to exercise the plan caching/invalidation mechanism
--
CREATE TEMP TABLE pcachetest AS SELECT * FROM int8_tbl;
-- create and use a cached plan
PREPARE prepstmt AS SELECT * FROM pcachetest;
EXECUTE prepstmt;
        q1        |        q2         
------------------+-------------------
              123 |               456
              123 |  4567890123456789
 4567890123456789 |               123
 4567890123456789 |  4567890123456789
 4567890123456789 | -4567890123456789
(5 rows)

-- and one with parameters
PREPARE prepstmt2(bigint) AS SELECT * FROM pcachetest WHERE q1 = $1;
EXECUTE prepstmt2(123);
 q1  |        q2        
-----+------------------
 123 |              456
 123 | 4567890123456789
(2 rows)

-- invalidate the plans and see what happens
DROP TABLE pcachetest;
EXECUTE prepstmt;
ERROR:  relation "pcachetest" does not exist
EXECUTE prepstmt2(123);
ERROR:  relation "pcachetest" does not exist
-- recreate the temp table (this demonstrates that the raw plan is
-- purely textual and doesn't depend on OIDs, for instance)
CREATE TEMP TABLE pcachetest AS SELECT * FROM int8_tbl ORDER BY 2;
EXECUTE prepstmt;
        q1        |        q2         
------------------+-------------------
 4567890123456789 | -4567890123456789
 4567890123456789 |               123
              123 |               456
              123 |  4567890123456789
 4567890123456789 |  4567890123456789
(5 rows)

EXECUTE prepstmt2(123);
 q1  |        q2        
-----+------------------
 123 |              456
 123 | 4567890123456789
(2 rows)

-- prepared statements should prevent change in output tupdesc,
-- since clients probably aren't expecting that to change on the fly
ALTER TABLE pcachetest ADD COLUMN q3 bigint;
EXECUTE prepstmt;
ERROR:  cached plan must not change result type
EXECUTE prepstmt2(123);
ERROR:  cached plan must not change result type
-- but we're nice guys and will let you undo your mistake
ALTER TABLE pcachetest DROP COLUMN q3;
EXECUTE prepstmt;
        q1        |        q2         
------------------+-------------------
 4567890123456789 | -4567890123456789
 4567890123456789 |               123
              123 |               456
              123 |  4567890123456789
 4567890123456789 |  4567890123456789
(5 rows)

EXECUTE prepstmt2(123);
 q1  |        q2        
-----+------------------
 123 |              456
 123 | 4567890123456789
(2 rows)

-- Try it with a view, which isn't directly used in the resulting plan
-- but should trigger invalidation anyway
CREATE TEMP VIEW pcacheview AS
  SELECT * FROM pcachetest;
PREPARE vprep AS SELECT * FROM pcacheview;
EXECUTE vprep;
        q1        |        q2         
------------------+-------------------
 4567890123456789 | -4567890123456789
 4567890123456789 |               123
              123 |               456
              123 |  4567890123456789
 4567890123456789 |  4567890123456789
(5 rows)

CREATE OR REPLACE TEMP VIEW pcacheview AS
  SELECT q1, q2/2 AS q2 FROM pcachetest;
EXECUTE vprep;
        q1        |        q2         
------------------+-------------------
 4567890123456789 | -2283945061728394
 4567890123456789 |                61
              123 |               228
              123 |  2283945061728394
 4567890123456789 |  2283945061728394
(5 rows)

-- Check basic SPI plan invalidation
create function cache_test(int) returns int as $$
declare total int;
begin
	create temp table t1(f1 int);
	insert into t1 values($1);
	insert into t1 values(11);
	insert into t1 values(12);
	insert into t1 values(13);
	select sum(f1) into total from t1;
	drop table t1;
	return total;
end
$$ language plpgsql;
select cache_test(1);
 cache_test 
------------
         37
(1 row)

select cache_test(2);
 cache_test 
------------
         38
(1 row)

select cache_test(3);
 cache_test 
------------
         39
(1 row)

-- Check invalidation of plpgsql "simple expression"
create temp view v1 as
  select 2+2 as f1;
create function cache_test_2() returns int as $$
begin
	return f1 from v1;
end$$ language plpgsql;
select cache_test_2();
 cache_test_2 
--------------
            4
(1 row)

create or replace temp view v1 as
  select 2+2+4 as f1;
select cache_test_2();
 cache_test_2 
--------------
            8
(1 row)

create or replace temp view v1 as
  select 2+2+4+(select max(unique1) from tenk1) as f1;
select cache_test_2();
 cache_test_2 
--------------
        10007
(1 row)

--- Check that change of search_path is ignored by replans
create schema s1
  create table abc (f1 int);
create schema s2
  create table abc (f1 int);
insert into s1.abc values(123);
insert into s2.abc values(456);
set search_path = s1;
prepare p1 as select f1 from abc;
execute p1;
 f1  
-----
 123
(1 row)

set search_path = s2;
select f1 from abc;
 f1  
-----
 456
(1 row)

execute p1;
 f1  
-----
 123
(1 row)

alter table s1.abc add column f2 float8;   -- force replan
execute p1;
 f1  
-----
 123
(1 row)

drop schema s1 cascade;
NOTICE:  drop cascades to table s1.abc
drop schema s2 cascade;
NOTICE:  drop cascades to table abc
reset search_path;
-- Check that invalidation deals with regclass constants
create temp sequence seq;
prepare p2 as select nextval('seq');
execute p2;
 nextval 
---------
       1
(1 row)

drop sequence seq;
create temp sequence seq;
execute p2;
 nextval 
---------
       1
(1 row)

-- Check DDL via SPI, immediately followed by SPI plan re-use
-- (bug in original coding)
create function cachebug() returns void as $$
declare r int;
begin
  drop table if exists temptable cascade;
  create temp table temptable as select * from generate_series(1,3) as f1;
  create temp view vv as select * from temptable;
  for r in select * from vv loop
    raise notice '%', r;
  end loop;
end$$ language plpgsql;
select cachebug();
NOTICE:  table "temptable" does not exist, skipping
CONTEXT:  SQL statement "drop table if exists temptable cascade"
PL/pgSQL function "cachebug" line 3 at SQL statement
NOTICE:  1
NOTICE:  2
NOTICE:  3
 cachebug 
----------
 
(1 row)

select cachebug();
NOTICE:  drop cascades to rule _RETURN on view vv
CONTEXT:  SQL statement "drop table if exists temptable cascade"
PL/pgSQL function "cachebug" line 3 at SQL statement
NOTICE:  drop cascades to view vv
CONTEXT:  SQL statement "drop table if exists temptable cascade"
PL/pgSQL function "cachebug" line 3 at SQL statement
NOTICE:  1
NOTICE:  2
NOTICE:  3
 cachebug 
----------
 
(1 row)