Re: Re: Re: [sqlite] Poor performance searching from multiple DBs

[chinasky65]

>It's not the first field in the index, so I don't think it >will use it

>for searching on "WHERE field5 = 'xxx'  ".



>Try adding an index on field5 only



> CREATE UNIQUE INDEX main_indexf5 ON main (field5);





>I don't see any problem.



Thanks Jay.

You are right.

The query in a PC change from 34 Secs to 0,036 secs.

Nice.



Thanks for your suggestions.

China.



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Re: Re: [sqlite] Poor performance searching from multiple DBs

[Jay Sprenkle]

> >> I have to search for field5 in some DB files (30 or more >>for a total of 
> >> 50 GB of   space and 150 M of records ).
> 
> >> select * from main where field5= "AABBCCDD";
> 
> 
> 
> > Did you put an index on field5?
> 
> Yes I use:
> 
> CREATE UNIQUE INDEX main_index ON main (field2,field5,field7);

It's not the first field in the index, so I don't think it will use it
for searching on "WHERE field5 = 'xxx'  ".

Try adding an index on field5 only

 CREATE UNIQUE INDEX main_indexf5 ON main (field5);

> 
> 
> 
> Is a quite complex index used for eliminating duplicates, is it OK?

I don't see any problem.

Re: Re: [sqlite] Poor performance searching from multiple DBs

[chinasky65]

>> I have to search for field5 in some DB files (30 or more >>for a total of 50 
>> GB of   space and 150 M of records ).

>> select * from main where field5= "AABBCCDD";



> Did you put an index on field5?

Yes I use:

CREATE UNIQUE INDEX main_index ON main (field2,field5,field7);



Is a quite complex index used for eliminating duplicates, is it OK?



China.

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