Re: Help: Why does a query go from 4 secs to 2 hrs due to using NOT IN instead of NOT EXISTS

On 6 Jul 2004 12:53:09 -0500, colin_lyse_at_yahsd.com (colin_lyse) wrote:

>In article <09q9e09gjo3nfg0h06s31ljk9709gcu0p0_at_4ax.com>, sybrandb_at_hccnet.nl wrote:
>>On 1 Jul 2004 12:14:09 -0500, colin_lyse_at_yahsd.com (colin_lyse) wrote:
>>You should also do away with your upper() on the lefthand side of all
>>your conditions in the where clause of your index, as the likely
>>result is you can't use an index anymore, as the full table scan on
>>lm_exception_list is actually showing you.
>
>thanks that did it, taking away the upper changed it
>
>>Also you should replace the b.id in your subquery by 'x'.
>>If your b.id doesn't occur in an index, the table will be read. If you
>>are using 'x', the subquery will just read the index.
>
>what do u mean by 'x' how od i change b.id to 'x', do you mean put 'b.id'?

I meant the sequence 'x', actually any dummy character would do, to avoid reading the actual record.

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Sybrand Bakker, Senior Oracle DBA