parallel query and latch waits
Posted on 2001-06-07
I have a table set up with parallel degree 4
the table is spread out across 4 physical disk mounts.
Everything run great except if I have a subquery
from fact_table --parallel degree 4
where user_id in (select user_id
where external_role_type IN('Named User', 'Registered User')
latch waits are 60% of non-idle wait time (from spotlight)
What can I do to reduce this latch problem?
If I remove parallel from the fact table I do not have a problem with latches?