agreed On Sep 10, 2014, at 3:27 PM, olek.stas...@gmail.com wrote:
> You're right, there is no data in tombstone, only a column name. So
> there is only small overhead of disk size after delete. But i must
> agree with post above, it's pointless in deleting prior to inserting.
> Moreover, it needs one op more to compute resulting row.
> cheers,
> Olek
>
> 2014-09-10 22:18 GMT+02:00 graham sanderson <gra...@vast.com>:
>> delete inserts a tombstone which is likely smaller than the original record
>> (though still (currently) has overhead of cost for full key/column name
>> the data for the insert after a delete would be identical to the data if you
>> just inserted/updated
>>
>> no real benefit I can think of for doing the delete first.
>>
>> On Sep 10, 2014, at 2:25 PM, olek.stas...@gmail.com wrote:
>>
>>> I think so.
>>> this is how i see it:
>>> on the very beginning you have such line in datafile:
>>> {key: [col_name, col_value, date_of_last_change]} //something similar,
>>> i don't remember now
>>>
>>> after delete you're adding line:
>>> {key:[col_name, last_col_value, date_of_delete, 'd']} //this d
>>> indicates that field is deleted
>>> after insert the following line is added:
>>> {key: [col_name, col_value, date_of_insert]}
>>> so delete and then insert generates 2 lines in datafile.
>>>
>>> after pure insert (upsert in fact) you will have only one line
>>> {key: [col_name, col_value, date_of_insert]}
>>> So, summarizing, in second scenario you have only one line, in first: two.
>>> I hope my post is correct ;)
>>> regards,
>>> Olek
>>>
>>> 2014-09-10 18:56 GMT+02:00 Michal Budzyn <michalbud...@gmail.com>:
>>>> Would the factor before compaction be always 2 ?
>>>>
>>>> On Wed, Sep 10, 2014 at 6:38 PM, olek.stas...@gmail.com
>>>> <olek.stas...@gmail.com> wrote:
>>>>>
>>>>> IMHO, delete then insert will take two times more disk space then
>>>>> single insert. But after compaction the difference will disappear.
>>>>> This was true in version prior to 2.0, but it should still work this
>>>>> way. But maybe someone will correct me, if i'm wrong.
>>>>> Cheers,
>>>>> Olek
>>>>>
>>>>> 2014-09-10 18:30 GMT+02:00 Michal Budzyn <michalbud...@gmail.com>:
>>>>>> One insert would be much better e.g. for performance and network
>>>>>> latency.
>>>>>> I wanted to know if there is a significant difference (apart from
>>>>>> additional
>>>>>> commit log entry) in the used storage between these 2 use cases.
>>>>>>
>>>>
>>>>
>>
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