Important queries on 10g performance

to get breakup of wait

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select wait_class,time_waited from v$system_wait_class order by time_waited;

pga target allocation

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select pga_target_for_estimate "size",
pga_target_factor "factor",
estd_extra_bytes_rw/1000000 "extra Mb r/w",
estd_overalloc_count "over allocations"
from v$pga_target_advice;

db_cache advice

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select name,size_for_estimate, size_factor, estd_physical_reads from v$db_cache_advice;