postgresql/contrib/pgstattuple/sql/pgstattuple.sql

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CREATE EXTENSION pgstattuple;
--
-- It's difficult to come up with platform-independent test cases for
-- the pgstattuple functions, but the results for empty tables and
-- indexes should be that.
--
create table test (a int primary key, b int[]);
select * from pgstattuple('test');
select * from pgstattuple('test'::text);
select * from pgstattuple('test'::name);
select * from pgstattuple('test'::regclass);
select pgstattuple(oid) from pg_class where relname = 'test';
select pgstattuple(relname) from pg_class where relname = 'test';
Fix multiple bugs in contrib/pgstattuple's pgstatindex() function. 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 d287818eb514d431. 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.
2016-02-18 21:40:35 +01:00
select version, tree_level,
index_size / current_setting('block_size')::int as index_size,
root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
avg_leaf_density, leaf_fragmentation
from pgstatindex('test_pkey');
select version, tree_level,
index_size / current_setting('block_size')::int as index_size,
root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
avg_leaf_density, leaf_fragmentation
from pgstatindex('test_pkey'::text);
select version, tree_level,
index_size / current_setting('block_size')::int as index_size,
root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
avg_leaf_density, leaf_fragmentation
from pgstatindex('test_pkey'::name);
select version, tree_level,
index_size / current_setting('block_size')::int as index_size,
root_block_no, internal_pages, leaf_pages, empty_pages, deleted_pages,
avg_leaf_density, leaf_fragmentation
from pgstatindex('test_pkey'::regclass);
select pg_relpages('test');
select pg_relpages('test_pkey');
select pg_relpages('test_pkey'::text);
select pg_relpages('test_pkey'::name);
select pg_relpages('test_pkey'::regclass);
select pg_relpages(oid) from pg_class where relname = 'test_pkey';
select pg_relpages(relname) from pg_class where relname = 'test_pkey';
create index test_ginidx on test using gin (b);
select * from pgstatginindex('test_ginidx');
create index test_hashidx on test using hash (b);
select * from pgstathashindex('test_hashidx');