AW: AW: [DIRECT-L Valentina 2.0. -- What is your 3 DREAMfeatures? // XML

[Ruslan Zasukhin]

on 2/3/04 12:19 PM, Florian Bogeschdorfer at fb at memedia.de wrote:

>> Yes, this feature is interesting.
>>     ability store cursor to disk, and re-create it back AS CURSOR.
>> 
>> I want EXPLAIN potential problems:
>> * very often our cursor do not create TMP table, just keep
>> pointers on original table.
>> * I think we cannot SAVE this pointers to disk, because
>> records can be deleted, and replaced by new, so pointers will
>> be quite wrong.
> 
> I don't think this is a problem. If you store a cursor to disk I would store
> the unique record Ids. Since RecId from Valentina is reused, it must be
> something else. Now if I store a cursor, I know very well that it might be
> outdated tomorrow, but never mind. You could load the cursor, recreate it
> according to the saved Ids (this is one table again!) and maybe issue an
> event that xx records are no longer available. This would be sooooo smooth!!

No Florian,

1) Valentina cursor, internally use RecIDs and only RecIDs.
    I cannot use anything else.

2) now. You save cursor that have e.g. RecId = 5.
    other user delete record 5.
    later second user add record, and Valentina reuse RecID 5

At morning you read your cursor back, you think that all is right,
But NO. Record with RecID = 5 most probably is WRONG and do not satisfy
conditions of cursor.

There is no way to find such glitch.

Well, way exists only when we add TimeStamp to each record of database.
Then yes, I will be able recognize that record 5 was CHANGED after cursor
creation and do something.


>> Only way -- create TMP table -- as result of such SAVING.
>> This means total coping of data of all records of cursor.
>> You still want such feature?  :-)
> 
> Yes, still interesting. Imagine a company making a mailing again. It's large
> and then 100000 letters should be spread over 4 weeks, say 25000 a week. Now
> data might change in this 4 weeks, but your mailing should ignore this. You
> need a quite complicated workaround for this. But if I could store the TMP
> table even with all the date it would be brilliant - just load the cursor
> and continue.

So what problems? CREATE TMP table, copy data,
And use that Table during weeks.
Actually then it must not be marked as TMP.

> So I think there should be two ways to save cursors: tmp table with all data
> and cursor with Ids only. I would love this.
> 
> Also this would be a way to share cursors. Right now client2 can not access
> a cursor from client1 right? Even if it is serverside. With save/load this
> would work.

Hmm, really incredible features :-)


-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
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e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

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