Eine aufbereitete Darstellung der Quelle

 
     
 
 
Anforderungen  |   Konzepte  |   Entwurf  |   Entwicklung  |   Qualitätssicherung  |   Lebenszyklus  |   Steuerung
 
 
 
 

Benutzer

Quelle  page.out   Sprache: unbekannt

 
Spracherkennung für: .out vermutete Sprache: Unknown {[0] [0] [0]} [Methode: Schwerpunktbildung, einfache Gewichte, sechs Dimensionen]

CREATE EXTENSION pageinspect;
-- Use a temp table so that effects of VACUUM are predictable
CREATE TEMP TABLE test1 (a int, b int);
INSERT INTO test1 VALUES (16777217131584);
VACUUM (DISABLE_PAGE_SKIPPING) test1;  -- set up FSM
-- The page contents can vary, so just test that it can be read
-- successfully, but don't keep the output.
SELECT octet_length(get_raw_page('test1', 'main', 0)) AS main_0;
 main_0 
--------
   8192
(1 row)

SELECT octet_length(get_raw_page('test1', 'main', 1)) AS main_1;
ERROR:  block number 1 is out of range for relation "test1"
SELECT octet_length(get_raw_page('test1', 'fsm', 0)) AS fsm_0;
 fsm_0 
-------
  8192
(1 row)

SELECT octet_length(get_raw_page('test1', 'fsm', 1)) AS fsm_1;
 fsm_1 
-------
  8192
(1 row)

SELECT octet_length(get_raw_page('test1', 'vm', 0)) AS vm_0;
 vm_0 
------
 8192
(1 row)

SELECT octet_length(get_raw_page('test1', 'vm', 1)) AS vm_1;
ERROR:  block number 1 is out of range for relation "test1"
SELECT octet_length(get_raw_page('test1', 'main', -1));
ERROR:  invalid block number
SELECT octet_length(get_raw_page('xxx', 'main', 0));
ERROR:  relation "xxx" does not exist
SELECT octet_length(get_raw_page('test1', 'xxx', 0));
ERROR:  invalid fork name
HINT:  Valid fork names are "main", "fsm", "vm", and "init".
SELECT get_raw_page('test1', 0) = get_raw_page('test1', 'main', 0);
 ?column? 
----------
 t
(1 row)

SELECT pagesize, version FROM page_header(get_raw_page('test1', 0));
 pagesize | version 
----------+---------
     8192 |       4
(1 row)

SELECT page_checksum(get_raw_page('test1', 0), 0) IS NOT NULL AS silly_checksum_test;
 silly_checksum_test 
---------------------
 t
(1 row)

SELECT page_checksum(get_raw_page('test1', 0), -1);
ERROR:  invalid block number
SELECT tuple_data_split('test1'::regclass, t_data, t_infomask, t_infomask2, t_bits)
    FROM heap_page_items(get_raw_page('test1', 0));
       tuple_data_split        
-------------------------------
 {"\\x01000001","\\x00020200"}
(1 row)

SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
 fsm_page_contents 
-------------------
 0254           +
 1254           +
 3254           +
 7254           +
 15254          +
 31254          +
 63254          +
 127254         +
 255254         +
 511254         +
 1023254        +
 2047254        +
 4095254        +
 fp_next_slot: 0  +
 
(1 row)

-- If we freeze the only tuple on test1, the infomask should
-- always be the same in all test runs.
VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) test1;
SELECT t_infomask, t_infomask2, raw_flags, combined_flags
FROM heap_page_items(get_raw_page('test1', 0)),
     LATERAL heap_tuple_infomask_flags(t_infomask, t_infomask2);
 t_infomask | t_infomask2 |                         raw_flags                         |   combined_flags   
------------+-------------+-----------------------------------------------------------+--------------------
       2816 |           2 | {HEAP_XMIN_COMMITTED,HEAP_XMIN_INVALID,HEAP_XMAX_INVALID} | {HEAP_XMIN_FROZEN}
(1 row)

-- tests for decoding of combined flags
-- HEAP_XMAX_SHR_LOCK = (HEAP_XMAX_EXCL_LOCK | HEAP_XMAX_KEYSHR_LOCK)
SELECT * FROM heap_tuple_infomask_flags(x'0050'::int, 0);
                  raw_flags                  |    combined_flags    
---------------------------------------------+----------------------
 {HEAP_XMAX_KEYSHR_LOCK,HEAP_XMAX_EXCL_LOCK} | {HEAP_XMAX_SHR_LOCK}
(1 row)

-- HEAP_XMIN_FROZEN = (HEAP_XMIN_COMMITTED | HEAP_XMIN_INVALID)
SELECT * FROM heap_tuple_infomask_flags(x'0300'::int, 0);
                raw_flags                |   combined_flags   
-----------------------------------------+--------------------
 {HEAP_XMIN_COMMITTED,HEAP_XMIN_INVALID} | {HEAP_XMIN_FROZEN}
(1 row)

-- HEAP_MOVED = (HEAP_MOVED_IN | HEAP_MOVED_OFF)
SELECT * FROM heap_tuple_infomask_flags(x'C000'::int, 0);
           raw_flags            | combined_flags 
--------------------------------+----------------
 {HEAP_MOVED_OFF,HEAP_MOVED_IN} | {HEAP_MOVED}
(1 row)

SELECT * FROM heap_tuple_infomask_flags(x'C000'::int, 0);
           raw_flags            | combined_flags 
--------------------------------+----------------
 {HEAP_MOVED_OFF,HEAP_MOVED_IN} | {HEAP_MOVED}
(1 row)

-- test all flags of t_infomask and t_infomask2
SELECT unnest(raw_flags)
  FROM heap_tuple_infomask_flags(x'FFFF'::int, x'FFFF'::int) ORDER BY 1;
        unnest         
-----------------------
 HEAP_COMBOCID
 HEAP_HASEXTERNAL
 HEAP_HASNULL
 HEAP_HASOID_OLD
 HEAP_HASVARWIDTH
 HEAP_HOT_UPDATED
 HEAP_KEYS_UPDATED
 HEAP_MOVED_IN
 HEAP_MOVED_OFF
 HEAP_ONLY_TUPLE
 HEAP_UPDATED
 HEAP_XMAX_COMMITTED
 HEAP_XMAX_EXCL_LOCK
 HEAP_XMAX_INVALID
 HEAP_XMAX_IS_MULTI
 HEAP_XMAX_KEYSHR_LOCK
 HEAP_XMAX_LOCK_ONLY
 HEAP_XMIN_COMMITTED
 HEAP_XMIN_INVALID
(19 rows)

SELECT unnest(combined_flags)
  FROM heap_tuple_infomask_flags(x'FFFF'::int, x'FFFF'::int) ORDER BY 1;
       unnest       
--------------------
 HEAP_MOVED
 HEAP_XMAX_SHR_LOCK
 HEAP_XMIN_FROZEN
(3 rows)

-- no flags at all
SELECT * FROM heap_tuple_infomask_flags(00);
 raw_flags | combined_flags 
-----------+----------------
 {}        | {}
(1 row)

-- no combined flags
SELECT * FROM heap_tuple_infomask_flags(x'0010'::int, 0);
        raw_flags        | combined_flags 
-------------------------+----------------
 {HEAP_XMAX_KEYSHR_LOCK} | {}
(1 row)

DROP TABLE test1;
-- check that using any of these functions with a partitioned table or index
-- would fail
create table test_partitioned (a int) partition by range (a);
create index test_partitioned_index on test_partitioned (a);
select get_raw_page('test_partitioned', 0); -- error about partitioned table
ERROR:  cannot get raw page from relation "test_partitioned"
DETAIL:  This operation is not supported for partitioned tables.
select get_raw_page('test_partitioned_index', 0); -- error about partitioned index
ERROR:  cannot get raw page from relation "test_partitioned_index"
DETAIL:  This operation is not supported for partitioned indexes.
-- a regular table which is a member of a partition set should work though
create table test_part1 partition of test_partitioned for values from ( 1 ) to (100);
select get_raw_page('test_part1', 0); -- get farther and error about empty table
ERROR:  block number 0 is out of range for relation "test_part1"
drop table test_partitioned;
-- check null bitmap alignment for table whose number of attributes is multiple of 8
create table test8 (f1 int, f2 int, f3 int, f4 int, f5 int, f6 int, f7 int, f8 int);
insert into test8(f1, f8) values (x'7f00007f'::int, 0);
select t_bits, t_data from heap_page_items(get_raw_page('test8', 0));
  t_bits  |       t_data       
----------+--------------------
 10000001 | \x7f00007f00000000
(1 row)

select tuple_data_split('test8'::regclass, t_data, t_infomask, t_infomask2, t_bits)
    from heap_page_items(get_raw_page('test8', 0));
                      tuple_data_split                       
-------------------------------------------------------------
 {"\\x7f00007f",NULL,NULL,NULL,NULL,NULL,NULL,"\\x00000000"}
(1 row)

drop table test8;
-- check storage of generated columns
-- stored
create table test9s (a int not null, b int generated always as (a * 2) stored);
insert into test9s values (131584);
select raw_flags, t_bits, t_data
    from heap_page_items(get_raw_page('test9s', 0)), lateral heap_tuple_infomask_flags(t_infomask, t_infomask2);
      raw_flags      | t_bits |       t_data       
---------------------+--------+--------------------
 {HEAP_XMAX_INVALID} |        | \x0002020000040400
(1 row)

select tuple_data_split('test9s'::regclass, t_data, t_infomask, t_infomask2, t_bits)
    from heap_page_items(get_raw_page('test9s', 0));
       tuple_data_split        
-------------------------------
 {"\\x00020200","\\x00040400"}
(1 row)

drop table test9s;
-- virtual
create table test9v (a int not null, b int generated always as (a * 2) virtual);
insert into test9v values (131584);
select raw_flags, t_bits, t_data
    from heap_page_items(get_raw_page('test9v', 0)), lateral heap_tuple_infomask_flags(t_infomask, t_infomask2);
            raw_flags             |  t_bits  |   t_data   
----------------------------------+----------+------------
 {HEAP_HASNULL,HEAP_XMAX_INVALID} | 10000000 | \x00020200
(1 row)

select tuple_data_split('test9v'::regclass, t_data, t_infomask, t_infomask2, t_bits)
    from heap_page_items(get_raw_page('test9v', 0));
   tuple_data_split   
----------------------
 {"\\x00020200",NULL}
(1 row)

drop table test9v;
-- Failure with incorrect page size
-- Suppress the DETAIL message, to allow the tests to work across various
-- page sizes.
\set VERBOSITY terse
SELECT fsm_page_contents('aaa'::bytea);
ERROR:  invalid page size
SELECT page_checksum('bbb'::bytea, 0);
ERROR:  invalid page size
SELECT page_header('ccc'::bytea);
ERROR:  invalid page size
\set VERBOSITY default
-- Tests with all-zero pages.
SHOW block_size \gset
SELECT fsm_page_contents(decode(repeat('00', :block_size), 'hex'));
 fsm_page_contents 
-------------------
 
(1 row)

SELECT page_header(decode(repeat('00', :block_size), 'hex'));
      page_header      
-----------------------
 (0/0,0,0,0,0,0,0,0,0)
(1 row)

SELECT page_checksum(decode(repeat('00', :block_size), 'hex'), 1);
 page_checksum 
---------------
              
(1 row)

-- tests for sequences
create sequence test_sequence start 72057594037927937;
select tuple_data_split('test_sequence'::regclass, t_data, t_infomask, t_infomask2, t_bits)
  from heap_page_items(get_raw_page('test_sequence', 0));
                   tuple_data_split                    
-------------------------------------------------------
 {"\\x0100000000000001","\\x0000000000000000","\\x00"}
(1 row)

drop sequence test_sequence;

[Dauer der Verarbeitung: 0.16 Sekunden, vorverarbeitet 2026-08-10]

                                                                                                                                                                                                                                                                                                                                                                                                     


Neuigkeiten

     Aktuelles
     Motto des Tages

Open Source Software

     Quellcodebibliothek
     Eigene Quellcodes
     Fremde Quellcodes
     Suchen

Jenseits des Üblichen ....
    

Besucherstatistik

Besucherstatistik

Statistik
#Sources=141584
#Domains=752002