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Oracle Top segments

I use the following query to display the top 20 hot segments which have the biggest logical reads today.

query:
with hotsegmentvw as
(
select * from
(
SELECT obj# obj_id ,dataobj# data_obj_id,
     sum(logical_reads_delta) AS total_logical_reads
FROM dba_hist_seg_stat a
WHERE     a.snap_id in (select snap_id from dba_hist_snapshot  where trunc(BEGIN_INTERVAL_TIME)=trunc(sysdate))
GROUP BY obj#,dataobj#
order by sum(logical_reads_delta) desc
)
where rownum <= 20
)

select owner,object_name, total_logical_reads from hotsegmentvw a,dba_objects b
where a.obj_id = b.object_id
     AND a.data_obj_id = b.data_object_id
order by total_logical_reads
/

sample result:

OWNER           OBJECT_NAME                    TOTAL_LOGICAL_READS
--------------- ------------------------------ -------------------
ODYSSEY         SPOT_CHANNEL_I4                          334938608
ODYSSEY         SCHEDULE_AVAIL                           369947968
BSS             VERSION_U1                               380481744
BSS             TABLE_LINE_PK                            420110048
BSS             SCHEDULE_ITEM_I11                        424232128
ODYSSEY         SPOT_CHANNEL                             434493104
IBMSTASK        TASK_SERVER_LOG_I1                       440787200
ODYSSEY         IMPRESSION_COPY_PK                       467589344
ODYSSEY         SPOT_CHANNEL_U3                          561695824
BSS             TABLE_LINE                               618886448
ODYSSEY         SCHEDULE_SECTION_PK                      630677792
ODYSSEY         SCHEDULE_AVAIL_PK                        633438400
ODYSSEY         SALES_PRODUCT_DAYPART                    650545904
BSS             SCHEDULE_ITEM_PK                         671033824
ODYSSEY         SPOT                                     709647104
ODYSSEY         SCHEDULE_EVENT                           841863248
ODYSSEY         SALES_PRODUCT_DAYPART_PK                 993979440
ODYSSEY         SCHEDULE_EVENT_PK                       1319646848
BISTAGE         TMP_SPOT_GOUPING_I1                     3438150208
ODYSSEY         SPOT_PK                                 4701989600

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