Re: Locking entire database

A simpler example,
In the context of one transaction i do many queries of the form
INSERT INTO table value WHERE value NOT IN TABLE;

If i have 2 processes running the same 100s of these at the same time i
end up with duplicates.
Even with isolation set to serializable
any ideas?
thnx

Panagiotis

Thomas Kellerer wrote:
> Panagiotis Pediaditis, 14.09.2007 16:45:
>> Well the problem is I am working on rdf query engine for persistent
>> RDF data. The data is stored/structured in a specific way in the
>> database. When i perform updates in parallel, because there are cross
>> table dependencies, I end up with inconsistencies, For example One
>> transaction reads to see if there is a resource so as to add a
>> property where it is a subject. Then an other transaction deletes the
>> resource after the first has decided that the resource is there but
>> before it added the property.
>> Thus it would be helpful for me to avoid the difficult task of
>> dependency based locking and just lock the whole database.
>> any ideas?
>
> Hmm. To me this sounds like all those steps should in fact be _one_
> transaction and not several transactions.
>
> Thomas
>
>
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