Optimize - Index deletion

Hi,

For a long time I tried to tune parameters and get the most of our iSeries for E1 8.12 / 8.98. I changed many parameters of JDE.INI, mostly with few (good) result and sometime with big disaster. I also tried to update and upgrade the machine or the web server but also with few result.

My best optimization were :
- adding RAM because of a lot of page faults
- limit COK creation and memory usage
- create a cluster of JAS
- add some indexes

My latest idea was to investigate indexes. One particular aspect is the number of indexes created by default. A lot of this indexes are never used. Eg :
<font class="small">Code:</font><hr /><pre>
SELECT
query_use_count,
query_statistics_count,
days_used_count,
CURRENT DATE - DATE(last_query_use) AS months_lastqry,
CURRENT DATE - DATE(last_statistics_use) AS months_laststats,
CURRENT DATE - DATE(last_used_timestamp) AS months_lastused,
concat(index_schema,concat('.',index_name)),
index_type,
last_query_use,
last_statistics_use,
last_used_timestamp
FROM qsys2.syspartitionindexstat
WHERE system_table_schema='PDDTA'
AND unique > 1
AND (query_use_count, query_statistics_count, days_used_count) = (0, 0, 0)
ORDER BY QUERY_USE_COUNT, QUERY_STATISTICS_COUNT
</pre><hr />

The only good advice I got is : it could be interesting but you need to gather data for 3 monthes first. Any opinion ?

Regards,