Subject | Re: [IBDI] Firebird 1 |
---|---|
Author | David Jencks |
Post date | 2001-06-01T03:12:34Z |
I tend to agree with you.
Do you have a problem with exposing the FIRST n functionality to possibly
limit the size of the data packets returned from the server?
david jencks
Do you have a problem with exposing the FIRST n functionality to possibly
limit the size of the data packets returned from the server?
david jencks
On 2001.05.31 22:52:47 -0400 Jason Wharton wrote:
> All this talk about the server delivering portions of a dataset based on
> ROWNUM ranges is nauseating.
>
> AFAIK, InterBase/Firebird does not have the concept of a row number on
> the
> server. This belongs on a client that is actually fetching data and
> counting
> rows as it goes and keeping them in a cache of its own. The server should
> not be required to keep hordes of caches around just to spit out small
> slices of datasets efficiently. Nor should it be made to re-execute
> queries
> over and over again just to increment through data.
>
> What should be happening is using bookmarks derived from meaningful data
> in
> your table that allows the server to quickly pull records from the next
> segment and then it just brings back rows until you don't want any more.
> When you want more records you somehow say, this is the new starting
> point
> and I want some more records starting from there. Interbase/Firebird
> handles
> that very well. IBO even automates with its various searching facilities.
>
> By doing it this way you are able to walk a batch of records more
> accurately. Row Nums are potentially inaccurate. They are always relative
> at
> best.
>
> e.g. Someone is browsing a web site and they see recs 1-50, while they
> are
> doing that one of the records they are looking at becomes deleted and
> then
> when they page to rows 51-100 the record that used to be 51 is now 50 and
> guess what, they never see that record. If instead their request for more
> records was based on records after the value for record 50 they would
> pick
> up that record and not miss it. using a snapshot transaction is
> definitely
> not a solution to this problem either.
>
> ROWNUM is simply for lazy programmers who don't really care if their
> applications work 100%. I vote for them to be banished from the engine
> even
> if any such semantics are already there. This part of the complexity
> should
> be solved on a middle tier or client. A server's job is to do
> transactions,
> optimize whatever queries I throw at it and keep data integrity.
>
> I suppose if you really want them it is a snap to write select stored
> procedures that provide a row num facility...
>
> Jason Wharton
> CPS - Mesa AZ
> http://www.ibobjects.com
>
>
>
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