[rt-users] DisGrouMem index

[Raed El-Hames]

Jesse;

Ah - In my database I do also have index GrouMem (GroupId,MemberId) on 
CachedGroupMembers
Your reply prompted me to have a look at the source code and it seems 
for one reason or another I may have created this index myself based on 
the Oracle schema some time in the past few years.

Considering there is (GroupId,MemberId) index, do you still recommend 
not to drop the DisGrouMem index (what will be the reason)?
I will need to drop one of them and I inclined to drop the 3 element 
index -- unless you tell me not to.

Regards;

Roy

Jesse Vincent wrote:
>
> On Wed, Apr 14, 2010 at 02:17:10PM +0100, Raed El-Hames wrote:
>   
>> Hi;
>>
>> rt-3.8.7
>> mysql 5.1
>>
>> Is the index  DisGrouMem (GroupId,MemberId,Disabled) required for 3.8
>>
>> When I did:
>> select * from CachedGroupMembers where Disabled = 1;
>> I got back 232 rows out of 5594612
>>
>> Which in my opinion makes that index useless ?
>>     
>
> My recollection is that MySQL can do just fine using the first component of a compound index.
>
>   
>> Ist required , can I drop it??
>>     
>
> I wouldn't recommend it.
>
>   
>> Regards;
>> Roy
>>
>>
>>
>>
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>>     
>
>