What is bad # for 'Space Allocated/Used" and 'ITL Waits' in V$SEGMENT_STATS

Question

I ran a query against the V$SEGMENT_STATISTICS view today and got some possibly disturbing numbers. Can some one let me know if they are bad or if I just reading to much into them.
DB has been up since 1/10/2011 so they represent the stats since then. DB size is 3TB
OBJECT_NAME     OBJECT_TYPE     STATISTIC_NAME     VALUE
XXPK0EMIANCE     INDEX     space allocated     27,246,198,784
ITEMINTANCE     TABLE     space allocated     22,228,762,624
LITEMINSTANCE     TABLE     space used     19,497,901,889
XXPK0TEMINSTANCE     INDEX     space used     17,431,957,592
TTINGCORE     TABLE     space allocated     8,724,152,320
XXPK0IANCE     INDEX     space allocated     6,912,212,992
SKISTANCE     TABLE     space allocated     4,697,620,480
IIXCNSTANCE     TABLE     space allocated     4,697,620,480
on the XXPK0EMIANCE index the inital extent is 64k
XXPK0MINSTANCE     INDEX     ITL waits     1,123
XXIEKILSTANCE     INDEX     ITL waits     467
XXPKLINSTANCE     INDEX     ITL waits     463
XXPKCE     INDEX     ITL waits     338
XXIE3ENT     INDEX     ITL waits     237
If these are bad do they impact performance? My understanding is that being wait states, things stop until they are resolved. Is that true.
Also these looked high, are they?
LATION_PK     INDEX     logical reads     242,212,503,104
XXAK1STSCORE     INDEX     logical reads     117,542,351,984
XXPK0TSTANCE     INDEX     logical reads     113,532,240,160
TCORE     TABLE     db block changes 1,913,902,176
SDENT     TABLE     physical reads     72,161,312
XXPK0PDUCT     INDEX     segment scans     35,268,027
ESTSORE     TABLE     buffer busy waits     2,604,947
XXPK0SUCORE     INDEX     buffer busy waits     119,007
XXPK0INSTANCE     INDEX     row lock waits     63,810
XXPK0EMINSTANCE     INDEX row lock waits     58,129
XXPK0NSTANCE     INDEX     row lock waits     57,776
XXIE2DDSTANCE     INDEX     row lock waits     54,788
XXPK0DDDSTSCORE     INDEX row lock waits     49,167
Am i just reading too much into this? I am not a DBA, our DBA is too busy doing data changes and such to spent time looking at these stuff. I was tasked to try to find out why our DB is so slow.

Answer 1

Statistics on waits and reads are cumulative since the last database instance startup --- which was more than 4 months ago.
So :
XXPK0MINSTANCE INDEX ITL waits 1,1231,123 waits in 4+ months isn't bad.
Reading such statistics without reference to the duration is utterly meaningless.
Those 1,123 waits could have been 10 waits a day @1 every 2 hours.
OR those 1,123 waits could have occurred between 01:00 and 01:30 on 03-May-2011.
We have no way of knowing which is the case.
Hemant K Chitale