Board index » delphi » SQL Server 7 and Blobs, Error: Blob Handle Invalid

SQL Server 7 and Blobs, Error: Blob Handle Invalid

I have problems fetching rows using SQL through the SQLExplorer and TQuery
from SQL Server tables. I get the error Invalid Blob Handle. If I fetch a
small subset of the table using a WHERE clause it works fine.
Most of the Blobs which are just text Memos are empty anyway.

I can view the table using the Data page of SQL Explorer, however I cannot
pass the SQL statements on the SQL page.

I have created the BDE Alias under Delphi 4 and am using the latest patch
and BDE version. I have also tried increasing Blob Size to 64 ( double ) and
Blobs To Cache to 128 ( double again ), no luck.

Any ideas? Tia

Dave Bhatia

 

Re:SQL Server 7 and Blobs, Error: Blob Handle Invalid


Try BLOBS TO CACHE in thousands (2000, etc.).  128 is not very many.

V/R
Russell L. Smith

Quote
Dave Bhatia wrote in message <75m81m$8c...@forums.borland.com>...
>I have created the BDE Alias under Delphi 4 and am using the latest patch
>and BDE version. I have also tried increasing Blob Size to 64 ( double )
and
>Blobs To Cache to 128 ( double again ), no luck.

Re:SQL Server 7 and Blobs, Error: Blob Handle Invalid


The BLOBS TO CACHE should be greater than the no.of rows you are fecthing on a
result set.
ie, if your query returns 1000 rows make sure your BLOBS TO CACHE is atleast
1000.
All these problem will go away if you work with properly INDEXED tables.

T.Ramesh.

Quote
Dave Bhatia wrote:
> I have problems fetching rows using SQL through the SQLExplorer and TQuery
> from SQL Server tables. I get the error Invalid Blob Handle. If I fetch a
> small subset of the table using a WHERE clause it works fine.
> Most of the Blobs which are just text Memos are empty anyway.

> I can view the table using the Data page of SQL Explorer, however I cannot
> pass the SQL statements on the SQL page.

> I have created the BDE Alias under Delphi 4 and am using the latest patch
> and BDE version. I have also tried increasing Blob Size to 64 ( double ) and
> Blobs To Cache to 128 ( double again ), no luck.

> Any ideas? Tia

> Dave Bhatia

Re:SQL Server 7 and Blobs, Error: Blob Handle Invalid


What about TQuery and cached updates?  I haven't found that indexing makes a
difference.  Maybe I am missing something.

V/R
Russell L. Smith

Quote
Ramesh Theivendran wrote in message <367EF4B0.E7E90...@inprise.com>...
>All these problem will go away if you work with properly INDEXED tables.

Re:SQL Server 7 and Blobs, Error: Blob Handle Invalid


Unique Index makes a difference on Live TQuery. Dead query and Cached updates
will still have the problem.

T.Ramesh.

Quote
Russell L. Smith wrote:
> What about TQuery and cached updates?  I haven't found that indexing makes a
> difference.  Maybe I am missing something.

> V/R
> Russell L. Smith

> Ramesh Theivendran wrote in message <367EF4B0.E7E90...@inprise.com>...
> >All these problem will go away if you work with properly INDEXED tables.

Re:SQL Server 7 and Blobs, Error: Blob Handle Invalid


don't be afaid to set the 'blobs to cache' up there. You have to cover the
worst case query answer dataset situation.

You'll run into the problem when the user attempts scroll or jump BACK more
blobs then the setting. I up'd mine to 1500. Never had a problem again.

Gene

(MS SQL Server)

-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/       Search, Read, Discuss, or Start Your Own    

Other Threads