Re: Phantom Inserts
Date: 24 Feb 95 11:21:45 GMT
Message-ID: <3ikkjp$qi6_at_jac.zko.dec.com>
In article <793588545snz_at_granby.demon.co.uk>, bh_at_granby.demon.co.uk (Bruce Horrocks) writes...
. . .
>
>Funny how both the responses form Oracle personnel mentioned Rdb
>rather than (original) Oracle.
Since the original posting was in the comp.databases.rdb newsgroup and we tend to follow it closely...
. . .>>BTW, how important is the protection against phantom inserts anyway?
>>
>>It doesn't seem common in applications that I have seen.
>
>I don't think that I've ever had to worry about it in any application
>that I've written. Doing the same select twice in a row in the same
>transaction would be so obviously inefficient that I would try to
>design around it as a matter of course.
>
>Regards,
>
>--
>-------------------------------------------------------------------------------
>Bruce Horrocks
>Hampshire, England Object Oriented programmers only
> need two methods - Create and Scoop-Up
>bh_at_granby.demon.co.uk
>-------------------------------------------------------------------------------
But phantom protection is in this tread has been shown in its most primitive form...of really pairing a select and either an insert/update or select together. When a database engine supports other features that the industry requires such as referential integrity it becomes much more complex [but can always be broken down to the primitives presented]. The fact of the matter is, when a database engine supports referential, the many applications that you have developed would have no clue of this requirement. The bottom line is that although your statement and mind set is true for the applications that you've developed...phantom prevention can be a requirement for the database that you run your application against, but you never see it.
Again, since this is posted in the Oracle Rdb conference...yes Rdb does support this.
- Jay Feenan ***
- Oracle Rdb Engineering ***
- ***
- opinions expressed here are solely my own and not those of my ***
- employer. ***
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