After examining the benchmark design - I see we are probably not being
helped by the repeated insertion of keys all of form 'userxxxxxxx'
leading to some page splitting.
However your index rebuild gets you from 5 to 3 GB - does that really
help performance significantly?
regards
Mark
On 11/08/16 16:08, Kisung Kim wrote:
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.
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