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48e6c943e5
Dead or half-dead index leaf pages were incorrectly reported as live, as a
consequence of a code rearrangement I made (during a moment of severe brain
fade, evidently) in commit d287818eb5.
The index metapage was not counted in index_size, causing that result to
not agree with the actual index size on-disk.
Index root pages were not counted in internal_pages, which is inconsistent
compared to the case of a root that's also a leaf (one-page index), where
the root would be counted in leaf_pages. Aside from that inconsistency,
this could lead to additional transient discrepancies between the reported
page counts and index_size, since it's possible for pgstatindex's scan to
see zero or multiple pages marked as BTP_ROOT, if the root moves due to
a split during the scan. With these fixes, index_size will always be
exactly one page more than the sum of the displayed page counts.
Also, the index_size result was incorrectly documented as being measured in
pages; it's always been measured in bytes. (While fixing that, I couldn't
resist doing some small additional wordsmithing on the pgstattuple docs.)
Including the metapage causes the reported index_size to not be zero for
an empty index. To preserve the desired property that the pgstattuple
regression test results are platform-independent (ie, BLCKSZ configuration
independent), scale the index_size result in the regression tests.
The documentation issue was reported by Otsuka Kenji, and the inconsistent
root page counting by Peter Geoghegan; the other problems noted by me.
Back-patch to all supported branches, because this has been broken for
a long time.
133 lines
6.0 KiB
Plaintext
133 lines
6.0 KiB
Plaintext
CREATE EXTENSION pgstattuple;
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--
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-- It's difficult to come up with platform-independent test cases for
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-- the pgstattuple functions, but the results for empty tables and
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-- indexes should be that.
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--
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create table test (a int primary key, b int[]);
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select * from pgstattuple('test');
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table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent
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-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
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0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
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(1 row)
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select * from pgstattuple('test'::text);
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table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent
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-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
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0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
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(1 row)
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select * from pgstattuple('test'::name);
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table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent
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-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
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0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
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(1 row)
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select * from pgstattuple('test'::regclass);
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table_len | tuple_count | tuple_len | tuple_percent | dead_tuple_count | dead_tuple_len | dead_tuple_percent | free_space | free_percent
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-----------+-------------+-----------+---------------+------------------+----------------+--------------------+------------+--------------
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0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
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(1 row)
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select pgstattuple(oid) from pg_class where relname = 'test';
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pgstattuple
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---------------------
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(0,0,0,0,0,0,0,0,0)
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(1 row)
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select pgstattuple(relname) from pg_class where relname = 'test';
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pgstattuple
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---------------------
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(0,0,0,0,0,0,0,0,0)
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(1 row)
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select version, tree_level,
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index_size / current_setting('block_size')::int as index_size,
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root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
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avg_leaf_density, leaf_fragmentation
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from pgstatindex('test_pkey');
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version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
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---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
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2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | NaN | NaN
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(1 row)
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select version, tree_level,
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index_size / current_setting('block_size')::int as index_size,
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root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
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avg_leaf_density, leaf_fragmentation
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from pgstatindex('test_pkey'::text);
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version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
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---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
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2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | NaN | NaN
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(1 row)
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select version, tree_level,
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index_size / current_setting('block_size')::int as index_size,
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root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
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avg_leaf_density, leaf_fragmentation
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from pgstatindex('test_pkey'::name);
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version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
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---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
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2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | NaN | NaN
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(1 row)
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select version, tree_level,
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index_size / current_setting('block_size')::int as index_size,
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root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
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avg_leaf_density, leaf_fragmentation
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from pgstatindex('test_pkey'::regclass);
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version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
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---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
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2 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | NaN | NaN
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(1 row)
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select pg_relpages('test');
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pg_relpages
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-------------
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0
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(1 row)
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select pg_relpages('test_pkey');
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pg_relpages
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-------------
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1
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(1 row)
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select pg_relpages('test_pkey'::text);
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pg_relpages
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-------------
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1
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(1 row)
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select pg_relpages('test_pkey'::name);
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pg_relpages
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-------------
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1
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(1 row)
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select pg_relpages('test_pkey'::regclass);
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pg_relpages
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-------------
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1
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(1 row)
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select pg_relpages(oid) from pg_class where relname = 'test_pkey';
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pg_relpages
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-------------
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1
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(1 row)
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select pg_relpages(relname) from pg_class where relname = 'test_pkey';
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pg_relpages
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-------------
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1
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(1 row)
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create index test_ginidx on test using gin (b);
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select * from pgstatginindex('test_ginidx');
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version | pending_pages | pending_tuples
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---------+---------------+----------------
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2 | 0 | 0
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(1 row)
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