SQL> @latch_spins

LATCH TYPE                      SPIN GETS SLEEP GETS SPIN HIT RATE              
------------------------------ ---------- ---------- -------------              
cache buffers lru chain             44752     182595        19.68%              
redo allocation                     29218      66781        30.44%              
library cache                       18997      43535        30.38%              
cache buffers chains                11812      36001        24.70%              
redo copy                             606      18245         3.21%              
messages                             3968       8315        32.30%              
enqueue hash chains                  1139       6603        14.71%              
system commit number                 2312       5548        29.41%              
undo global data                      252       1327        15.96%              
session idle bit                      256       1198        17.61%              
enqueues                              165        861        16.08%              
transaction allocation                 80        535        13.01%              
list of block allocation               47        353        11.75%              
shared pool                           272        295        47.97%              
dml lock allocation                    36        199        15.32%              
global tx hash mapping                 36        184        16.36%              
latch wait list                        27         95        22.13%              
session allocation                     13         78        14.29%              
row cache objects                      89         76        53.94%              

ALL LATCHES                        114080     372833        23.43%