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Oracle statistik

Jasmin shahrzad
Last Modified: 2018-02-02
How to check the statistic is bad.  can i have a formula with cardinality and cost?
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Geert GOracle dba
Top Expert 2009

statistics are never bad, they can only be out of date

there is no real formula ... it depends what you are doing

first check user_tables (or dba_tables) in column last_analyzed
if that date is very old then gather stats

exec dbms_stats.gather_table_stats  ...

it's also possible the optimizer doesn't have enough information to find a good plan
or is checking too much conditions
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Geert GOracle dba
Top Expert 2009

bad ... evil ... good ... ugly
they made a lot of films about those words

the stats are correct a certain point in time
out of date after a certain time

change the data back and your stats are "good" again :)

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