[Lazarus] Sorting BufferDataset

[Santiago A.]

El 13/4/20 a las 12:43, Michael Van Canneyt via lazarus escribió:
>> So, if I want to process the dataset in different orders with 
>> TbufferDataset, before opening the dataset I must set MaxIndexesCount 
>> to all the orders I'm going to use.
>
> Yes.
>
>>
>> Am I right? Or I have missed something?
>
> You are right.
>
> Probably we should at least now offer the possibility to delete 
> indexes, and
> I am not sure the MaxIndexesCount is still needed. 

At least it is used.

If you create the indexes before opening the dataset, MaxIndexesCount is 
automatically updated to hold your indexes plus the two default indexes.

But in an active dataset, you can't call addindex more than 
MaxIndexesCount, and being aware that two slots are used by two default 
indexes. You may get "The maximum amount of indexes is reached."

By the way. I got "The maximum amount of indexes is reached." and I went 
mad trying to find where I was creating two indexes. Was I calling 
addindex twices before and I wasn't aware?. Finally I looked at the code 
and when you call addindex, it creates two indexes: 'DEFAULT_ORDER' and 
''. What are those two phantom indexes for? I couldn't find any 
documentation about




-- 
--------
Saludos
Santiago A.

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