On Thu, Dec 16, 2010 at 2:27 PM, Mladen Gogala
<mladen.gogala@xxxxxxxxxxx> wrote:
> 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:
Well, according to the code:
/*
* If the next leaf is on an earlier block, it means a
* fragmentation.
*/
if (opaque->btpo_next != P_NONE &&
opaque->btpo_next < blkno)
indexStat.fragments++;
And then the final value is calculated thus:
snprintf(values[j++], 32, "%.2f", (double)
indexStat.fragments / (double) indexStat.leaf_pages * 100.0);
This doesn't really match my definition of the word "fragmentation", though...
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
