Re: pgstattuple extension for indexes

Hi folks,

As I said on -PATCHES, I've been working on an utility to get
a b-tree index information. I'm happy to introduce
my new functions to you.

pgstattuple module provides a `pgstatindex()`, and other small
functions, which allow you to get b-tree internal information.
I believe this module will be helpful to know b-tree index deeply.

So please try it, send comment to me, and have fun.

Thanks,
--
NAGAYASU Satoshi <nagayasus@nttdata.co.jp>

-----------------------------------------------------
pgbench=# \x
Expanded display is on.
pgbench=# SELECT * FROM pgstatindex('accounts_pkey');
-[ RECORD 1 ]------+--------
version            | 2
tree_level         | 1
index_size         | 3588096
root_block_no      | 3
internal_pages     | 0
leaf_pages         | 437
empty_pages        | 0
deleted_pages      | 0
avg_leaf_density   | 59.5
leaf_fragmentation | 49.89
-----------------------------------------------------