Re: Btree Index on PostgreSQL and Wiredtiger (MongoDB3.2) - Mailing list pgsql-hackers
Thank you for your information.
Here is the result:
After insertions:
ycsb=# select * from pgstatindex('usertable_pkey');
version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
---------+------------+------------+---------------+----------------+------------+-------------+---------------+------------------+--------------------
2 | 3 | 5488721920 | 44337 | 4464 | 665545 | 0 | 0 | 52 | 11
(1 row)
After rebuild:
ycsb=# select * from pgstatindex('usertable_pkey');
version | tree_level | index_size | root_block_no | internal_pages | leaf_pages | empty_pages | deleted_pages | avg_leaf_density | leaf_fragmentation
---------+------------+-------
2 | 3 | 3154296832 | 41827 | 1899 | 383146 | 0 | 0 | 90.08 | 0
It seems like that rebuild has an effect to reduce the number of internal and leaf_pages and make more dense leaf pages.
On Wed, Aug 10, 2016 at 6:47 PM, Lukas Fittl <lukas@fittl.com> wrote:
On Wed, Aug 10, 2016 at 4:24 PM, Kisung Kim <kskim@bitnine.net> wrote:When I used the index bloating estimation script in https://github.com/ioguix/pgsql-bloat-estimation, the result is as follows:Regardless of the issue at hand, it might make sense to verify these statistics using pgstattuple - those bloat estimation queries can be wildly off at times.Best,Lukas--Lukas Fittl
Bitnine Global Inc., Kisung Kim, Ph.D
https://sites.google.com/site/kisungresearch/
E-mail : kskim@bitnine.net
Office phone : 070-4800-5890, 408-606-8602
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