Dave Crooke wrote:
There is a plugin called pgstattuple which can be quite informative
.... however, it actually does a full scan of the table / index files,
which may be a bit invasive depending on your environment and load.
http://www.postgresql.org/docs/current/static/pgstattuple.html
It's in the contrib (at least for 8.4), and so you have to import its
functions into your schema using the script in the contrib directory.
Cheers
Dave
I tried it with one of my databases:
testtrack=# select * from pgstatindex('public.defects_pkey');
version | tree_level | index_size | root_block_no | internal_pages |
leaf_pages | empty_pages | deleted_pages | avg_leaf_density |
leaf_fragmentation
---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+-------------------
-
2 | 1 | 827392 | 3 | 0
| 100 | 0 | 0 | 70.12
| 22
(1 row)
What is "leaf_fragmentation"? How is it defined? I wasn't able to find
out any definition of that number. How is it calculated. I verified that
running reindex makes it 0:
testtrack=# reindex table public.defects;
REINDEX
testtrack=# select * from pgstatindex('public.defects_pkey');
version | tree_level | index_size | root_block_no | internal_pages |
leaf_pages | empty_pages | deleted_pages | avg_leaf_density |
leaf_fragmentation
---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+-------------------
-
2 | 1 | 647168 | 3 | 0
| 78 | 0 | 0 | 89.67
| 0
(1 row)
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Mladen Gogala
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