[Monetdb-developers] Monetdb-developers Digest, Vol 22, Issue 4

Keulen, M. van (Maurice) m.vankeulen at utwente.nl
Fri Mar 28 09:35:13 CET 2008


Hi Peter,

Does it also mean that if I send a stream of messages to one server that 
all carry the same request-ID without waiting for a result of a message 
before sending out the next, that all are handled in the correct order 
and each is handled after completion of the previous one? In that case, 
it meets all my requirements. In fact, it gives much more than I ask for 
:-) I definitely like to follow any developments for this one!

Maurice.

Peter Boncz wrote:
> Hi,
>
> I read the digests of the monetdb mailing list, which in this case took more
> than a month to send me this discussion. That's pretty useless.. I will switch
> to immediate mails.
>
> Anyway, Jennie is currently working on getting the repeatable reads transactions
> working. This means that by passing a request-ID you will be guaranteed that all
> queries and updates execute on the same database image, i.e. a transaction. In
> case of update requests in the same transaction, these will be executed
> atomically using a 2PC protocol.
>  
> While this functionality is designed to be triggerered from XQuery queries, you
> client API could also generate the appropriate messages.
>
> It may not answer you needs regarding performance (you would send a
> read-request, update-request, prepare-request and commit-request), but it would
> answer your functional requirements AFAIS.
>
> Peter
>
>
>
>   
>> Message: 1
>> Date: Wed, 19 Mar 2008 12:30:20 +0100
>> From: "Keulen, M. van (Maurice)" <m.vankeulen at utwente.nl>
>> Subject: Re: [Monetdb-developers] [XQ] Mixing update/docmgmt/query
>> To: monetdb-developers at lists.sourceforge.net
>> Message-ID: <47E0F94C.4000709 at utwente.nl>
>> Content-Type: text/plain; charset=windows-1252; format=flowed
>>
>> Ying Zhang wrote:
>>     
>>>> Jennie: my SOAP-messages do not come from MonetDB/XQuery, but from 
>>>> outside (i.e., some scripting language).
>>>>         
>>> Then, an order can only be guaranteed if you, in your 
>>>       
>> scripts, send a 
>>     
>>> message, wait for result, and send the next message.  In all other 
>>> cases, unfortunately, no guarantee, as an xrpc server immediately 
>>> start handling a request when it's received.
>>>
>>> Jennie
>>>       
>> I thought so already. This is why I don't like to have to 
>> send multiple 
>> requests to do one thing (transaction). I'd rather be able to 
>> send one 
>> request to both do, say, an update and return a result, or add a 
>> document and return a result. The system so far doesn't allow 
>> me to do 
>> this, because I cannot define one query (or function in a 
>> module) that 
>> does both because of typing restrictions, and I also cannot send two 
>> separate queries in one request because of restrictions in the XRPC 
>> protocol.
>>
>> Any thoughts about achieving what I want?
>>
>> Maurice.
>>
>> -- 
>> ----------------------------------------------------------------------
>> Dr.Ir. M. van Keulen - Assistant Professor, Data Management Technology
>> Univ. of Twente, Dept of EEMCS, POBox 217, 7500 AE Enschede, 
>> Netherlands
>> Email: m.vankeulen at utwente.nl, Phone: +31 534893688, Fax: +31 
>> 534892927
>> Room: ZI 3039, WWW: http://www.cs.utwente.nl/~keulen
>>     
> *********************************
>
>   

-- 
----------------------------------------------------------------------
Dr.Ir. M. van Keulen - Assistant Professor, Data Management Technology
Univ. of Twente, Dept of EEMCS, POBox 217, 7500 AE Enschede, Netherlands
Email: m.vankeulen at utwente.nl, Phone: +31 534893688, Fax: +31 534892927
Room: ZI 3039, WWW: http://www.cs.utwente.nl/~keulen





More information about the developers-list mailing list