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Tue, Oct 17 2006 3:51 PMPermanent Link

"Jerry Hayes"
> While we are still on this subject, is the description of each table in
> the catalog or in the table
> header? I know there was a discussion in this newsgroup about this and
> some people
> felt the description of the table should be in each table, but my feeling
> is that the description
> of each table should be in the catalog - and I think this will have some
> advantages like
> perhaps faster table restructuring?

Probably wouldn't impact restructuring much, since the initial structure
read probably goes to memory anyway.

*However* it would be nice to have all structures and defs capable of being
in the catalog, so you could do something like:

create table x [from catalog y]

Tue, Oct 17 2006 4:13 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

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Email timyoung@elevatesoft.com

Manfredt,

<< Is it possible, in later versions of ElevateDB, to combine the index file
into its table file like in NexusDB? The single catalog file per database
and seperate file for each table is excellent. >>

No.  EDB uses fixed-length rows like DBISAM, so they cannot be combined with
index pages.

<< While we are still on this subject, is the description of each table in
the catalog or in the table header? >>

Every bit of metadata is in the catalog.  Nothing is stored in the tables
except the data and some bits of information to make sure that the table is
in synch with the catalog.

<< I know there was a discussion in this newsgroup about this and some
people felt the description of the table should be in each table, but my
feeling is that the description of each table should be in the catalog - and
I think this will have some advantages like perhaps faster table
restructuring? >>

It doesn't really affect restructuring that much, but it does make the table
files themselves slightly smaller, and compacts the metadata quite a bit.
The entire Elevate Software database (~70 tables with indexes, etc.) catalog
file is only 93k.  Of course, the catalog gets bigger as you add more bound
SQL items such as views, stored procedures, triggers, etc.

--
Tim Young
Elevate Software
www.elevatesoft.com


Wed, Oct 18 2006 10:45 AMPermanent Link

"Godfrey"
Hi Tim

Will EDB be more resistant to corrupted indexes than Dbisam?

Thanks
Godfrey


"Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in message
news:DCAD4335-3E95-430B-9259-50DD5DA885F4@news.elevatesoft.com...
> Manfredt,
>
> << Is it possible, in later versions of ElevateDB, to combine the index
> file into its table file like in NexusDB? The single catalog file per
> database and seperate file for each table is excellent. >>
>
> No.  EDB uses fixed-length rows like DBISAM, so they cannot be combined
> with index pages.
>
> << While we are still on this subject, is the description of each table in
> the catalog or in the table header? >>
>
> Every bit of metadata is in the catalog.  Nothing is stored in the tables
> except the data and some bits of information to make sure that the table
> is in synch with the catalog.
>
> << I know there was a discussion in this newsgroup about this and some
> people felt the description of the table should be in each table, but my
> feeling is that the description of each table should be in the catalog -
> and I think this will have some advantages like perhaps faster table
> restructuring? >>
>
> It doesn't really affect restructuring that much, but it does make the
> table files themselves slightly smaller, and compacts the metadata quite a
> bit. The entire Elevate Software database (~70 tables with indexes, etc.)
> catalog file is only 93k.  Of course, the catalog gets bigger as you add
> more bound SQL items such as views, stored procedures, triggers, etc.
>
> --
> Tim Young
> Elevate Software
> www.elevatesoft.com
>
>
>

Wed, Oct 18 2006 12:54 PMPermanent Link

"J. B. Ferguson"
Godfrey,

I have never had a corrupted index in DBIsam C/S mode. Are you running
in local mode? *Any* database can incur corrupted indices in local mode
if a user incorrectly shuts down the computer or an application,
especially if the DB is dirty.

--
Regards,
Jan Ferguson


Godfrey wrote:

> Hi Tim
>
> Will EDB be more resistant to corrupted indexes than Dbisam?
>
> Thanks
> Godfrey
>
>
> "Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in
> message
> news:DCAD4335-3E95-430B-9259-50DD5DA885F4@news.elevatesoft.com...
> > Manfredt,
> >
> > << Is it possible, in later versions of ElevateDB, to combine the
> > index  file into its table file like in NexusDB? The single catalog
> > file per  database and seperate file for each table is excellent. >>
> >
> > No.  EDB uses fixed-length rows like DBISAM, so they cannot be
> > combined  with index pages.
Wed, Oct 18 2006 4:02 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

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Email timyoung@elevatesoft.com

Godfrey,

<< Will EDB be more resistant to corrupted indexes than Dbisam? >>

There are internal "placemarks" in EDB for fail-safe writes that will be
implemented in the first minor release (not build) to EDB.  That and cached
updates are the two main things that will be in the first minor release.

--
Tim Young
Elevate Software
www.elevatesoft.com

Thu, Oct 19 2006 2:23 AMPermanent Link

"Godfrey"
I am using local mode.

Unfortunately I deal with the low end pos market.  These guys dont like
spending money on hardware
and they treat there systems very badly. I have tried to educate them.

Maybe I should switch to C/S but offen it is just a single terminal.

Regards
Godfrey

"J. B. Ferguson" <jbNOSPAMfergusonATgmailDOTcom> wrote in message
news:041D40D4-9A36-46B7-8BAB-8FA84241A924@news.elevatesoft.com...
> Godfrey,
>
> I have never had a corrupted index in DBIsam C/S mode. Are you running
> in local mode? *Any* database can incur corrupted indices in local mode
> if a user incorrectly shuts down the computer or an application,
> especially if the DB is dirty.
>
> --
> Regards,
> Jan Ferguson
>
>
> Godfrey wrote:
>
>> Hi Tim
>>
>> Will EDB be more resistant to corrupted indexes than Dbisam?
>>
>> Thanks
>> Godfrey
>>
>>
>> "Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in
>> message
>> news:DCAD4335-3E95-430B-9259-50DD5DA885F4@news.elevatesoft.com...
>> > Manfredt,
>> >
>> > << Is it possible, in later versions of ElevateDB, to combine the
>> > index  file into its table file like in NexusDB? The single catalog
>> > file per  database and seperate file for each table is excellent. >>
>> >
>> > No.  EDB uses fixed-length rows like DBISAM, so they cannot be
>> > combined  with index pages.

Thu, Oct 19 2006 2:30 AMPermanent Link

Manfredt Kavetu
Jerry, Tim, thanks for your informative reply.

--
Manfredt Kavetu
Thu, Oct 19 2006 3:49 AMPermanent Link

Roy Lambert

NLH Associates

Team Elevate Team Elevate

Godfrey


I do get corrupted indices occasionally (DBISAM isn't perfect). Two thoughts 1) always use the latest version 2) if you are getting corruption then look at FlushBuffers to make sure (well as best you can) that data is on the disk not in memory.

Roy Lambert
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