Re: Indexing question

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От
Tomasz Myrta
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Re: Indexing question
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3F4EFAB6.7030104@klaster.net
Ответ на
Indexing question (Alexander Priem)
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Re: Indexing question "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
> Hi all,
>  
> I have some tables (which can get pretty large) in which I want to 
> record 'current' data as well as 'historical' data. This table has 
> fields 'deleted' and 'deleteddate' (among other fields, of course). The 
> field 'deleted' is false be default. Every record that I want to delete 
> gets the value true for 'deleted' and 'deleteddate' is set to the date 
> of deletion.
>  
> Since these tables are used a lot by queries that only use 'current' 
> data, I have created a view with a where clause 'Where not deleted'. 
> Also, I have indexed field 'deleted'.


I think the best choice for your case is using conditional indexes. It 
should be much better than indexing 'deleted' field. I don't know on 
which exactly fields you have to create this index - you have to check 
it by yourself - what do you have in "where" clause?

Example:
create index some_index on your_table(id_field) where not deleted;


Regards,
Tomasz Myrta

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