Search notes:

Oracle latch: cache buffers chains

Count the numbers of cache buffers chains and cache buffers lru chains latches:

select
   count(*) cnt,
   name
from
   v$latch_children
where
   name like 'cache buffers %'
group by
   name;

Check value of hidden parameter _db_block_hash_latches (Number of database block hash latches). It should correspond to count(*) of cache buffers chain:

select
   v.ksppstvl    value_v,
   v.ksppstdfl   default_value_v,
   w.ksppstvl    value_w,
   w.ksppstdfl   default_value_w
from
   x$ksppi  par                      join
   x$ksppcv v on par.indx = v.indx   join
   x$ksppsv w on par.indx = w.indx
where
   par.ksppinm = '_db_block_hash_latches';

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