Firebird-Blob-Value over 30MB could not loaded

[AsterixBT]

Hello,

I have following enviroment:
Delphi 10.1 Berlin, IBDAC Version 5.7.27, SQL-Firebird 2.5.6

The Firebird-Database has: 2073 Tables, 2214 Views, 6111 Procedure, 6465 Triggers and a size of 12 GB
One small Table in the database has this structure:
CREATE TABLE TBLOB ( ID INTEGER NOT NULL, TEXT BLOB SUB_TYPE 0 SEGMENT SIZE 80);
In this table I have one record. The blobfield value ist a XML-file with a size of 58MB.
Now I have a TDBMemo-Field in a Delphiform to display the record, but IBDAC could not load the blob.
If i make the blobvalue less than 30 MB, it works fine.
Also the same without TDBMemo, wenn I try to copy the Blobstream from IBDAC-field to a other memorystream or filestream.
I try all Optionssettings inTIBCQuery: CacheBlobs (on/off), DefferedBlobRead (on/off), StreamedBlobs (on/off) and all combination of this settings. Nothing happend.

One important info about this topic.
When I take the same Firebirddatabase, make it empty, put only the blob-record into the database, then it works. The full database is not corrupt. Before testing I make Backup/Restore.

I tested with different firebird-databases, different computers and different networks and differnent firebirbservices.

Has anyone a idee?

Best regards
AsterixBT
(Germany)

[ViktorV]

In order to get a detailed answer, please compose a full sample demonstrating the specified behavior and send it to us using the contact form https://www.devart.com/company/contactform.html, including scripts for creating and filling database objects.

[AsterixBT]

Hello,

o.k., I make a sample.
But it takes a few days, because next week I'am not in the office.

Thank you!

AsterixBT

[AsterixBT]

Hello!

Today I want to create a enviroment (database, script, Delphisource) for testing.
So I take a firebird-database from our network on my local computer.
On local network I can not reproduce the error. I try the same on two other computers.
When the database with the big blob value is on local computer, it works.
So I think, it can be a timeout from the fbclient and some cache-handling.

I have to make more tests before.

Best regards
Gerd

[ViktorV]

When you have results on this issue, please let us know.