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Revert "Avoid the creation of the free space map for small heap relations".

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This feature was using a process local map to track the first few blocks
in the relation.  The map was reset each time we get the block with enough
freespace.  It was discussed that it would be better to track this map on
a per-relation basis in relcache and then invalidate the same whenever
vacuum frees up some space in the page or when FSM is created.  The new
design would be better both in terms of API design and performance.

List of commits reverted, in reverse chronological order:

06c8a5090e  Improve code comments in b0eaa4c51b.
13e8643bfc  During pg_upgrade, conditionally skip transfer of FSMs.
6f918159a9  Add more tests for FSM.
9c32e4c350  Clear the local map when not used.
29d108cdec  Update the documentation for FSM behavior..
08ecdfe7e5  Make FSM test portable.
b0eaa4c51b  Avoid creation of the free space map for small heap relations.

Discussion: https://postgr.es/m/20190416180452.3pm6uegx54iitbt5@alap3.anarazel.de
This commit is contained in:
Amit Kapila
2019-05-07 09:30:24 +05:30
parent af82f95abb
commit 7db0cde6b5
23 changed files with 107 additions and 686 deletions
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34
contrib/pageinspect/sql/page.sql
View File

@ -1,36 +1,26 @@
CREATE EXTENSION pageinspect;
CREATE TABLE test_rel_forks (a int);
-- Make sure there are enough blocks in the heap for the FSM to be created.
INSERT INTO test_rel_forks SELECT i from generate_series(1,2000) i;
CREATE TABLE test1 (a int, b int);
INSERT INTO test1 VALUES (16777217, 131584);
-- set up FSM and VM
VACUUM test_rel_forks;
VACUUM 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('test_rel_forks', 'main', 0)) AS main_0;
SELECT octet_length(get_raw_page('test_rel_forks', 'main', 100)) AS main_100;
SELECT octet_length(get_raw_page('test1', 'main', 0)) AS main_0;
SELECT octet_length(get_raw_page('test1', 'main', 1)) AS main_1;
SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 0)) AS fsm_0;
SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 20)) AS fsm_20;
SELECT octet_length(get_raw_page('test1', 'fsm', 0)) AS fsm_0;
SELECT octet_length(get_raw_page('test1', 'fsm', 1)) AS fsm_1;
SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 0)) AS vm_0;
SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 1)) AS vm_1;
SELECT octet_length(get_raw_page('test1', 'vm', 0)) AS vm_0;
SELECT octet_length(get_raw_page('test1', 'vm', 1)) AS vm_1;
SELECT octet_length(get_raw_page('xxx', 'main', 0));
SELECT octet_length(get_raw_page('test_rel_forks', 'xxx', 0));
SELECT octet_length(get_raw_page('test1', 'xxx', 0));
EXPLAIN (costs off, analyze on, timing off, summary off) SELECT * FROM
fsm_page_contents(get_raw_page('test_rel_forks', 'fsm', 0));
SELECT get_raw_page('test_rel_forks', 0) = get_raw_page('test_rel_forks', 'main', 0);
DROP TABLE test_rel_forks;
CREATE TABLE test1 (a int, b int);
INSERT INTO test1 VALUES (16777217, 131584);
SELECT get_raw_page('test1', 0) = get_raw_page('test1', 'main', 0);
SELECT pagesize, version FROM page_header(get_raw_page('test1', 0));
@ -39,6 +29,8 @@ SELECT page_checksum(get_raw_page('test1', 0), 0) IS NOT NULL AS silly_checksum_
SELECT tuple_data_split('test1'::regclass, t_data, t_infomask, t_infomask2, t_bits)
FROM heap_page_items(get_raw_page('test1', 0));
SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
DROP TABLE test1;
-- check that using any of these functions with a partitioned table or index