Passing large blob data

edwinsn · 2011-06-20 15:29:25

Hi Arnaud,

Performance-wise, what's the best way to pass TSqlRecord derived object with large blob data, say 10 MB's? The client will get large amount of blob data from the internet, and pass the data to the server which in turn save it to the DB (via your framework, of course), Q#1: is the named pipe protocol is the best choice?

I did some research, the developer of the original sqlite project suggested to design the table as such - store the blob data as the last field in the table, or even store the blob data in a separate table. Others said that increasing the page size of the DB will help in performance.

Q#2: Any other hints you can offer?

Thanks!

edwinsn · 2011-06-20 15:37:12

the background: I'm designing a DB to store millions of objects of different structure, so to make things simplified, the DB will only have two types of objects, or in other words, two tables:

TMyDocument = class(TSQLRecord)
PrimaryKey: Integer; //primary key of the object
MetaDataAsJSON: RawUTF8; //object properties in JSON format.
end;

//store blob datas of TMyDocument, can have many instances that are associated with TMyDocument.
TMyBlob = class(TSQLRecord)
PKey: Integer;//primary key
FKey: Integer;//foreign key, maps to TMyDocument.PrimaryKey
MetaDataAsJSON: blob;//blob data, I still don't know what data type to use here, but you should get my point.
end;

Last edited by edwinsn (2011-06-20 15:39:18)

ab · 2011-06-20 17:42:44

See the documentation, about BLOB data.

1. You'll have to define the BLOB fields as TSQLRawBlob
2. Let the default Blob retrieval setting, i.e. retrieve BLOB explicitely
3. Use RetrieveBlob() and UpdateBlob() methods

You have a good example of handling BLOB data in the main SynFile demo.

See the corresponding source code and the associated pages in the documentation (SAD document).

edwinsn · 2011-06-21 01:56:58

Hi Arnaud,

Thank you very much. That helps.

mORMot Open Source

#1 2011-06-20 15:29:25

Passing large blob data

#2 2011-06-20 15:37:12

Re: Passing large blob data

#3 2011-06-20 17:42:44

Re: Passing large blob data

#4 2011-06-21 01:56:58

Re: Passing large blob data

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