Speed of Blob-writing...

[Ruslan Zasukhin]

On 2/8/10 10:47 PM, "Thomas Flemming" <tf at ttqv.com> wrote:

Hi Thomas,

> its again about speed :-)
> 
> Im storing map data as Blobs.
> Works perfect and is very fast in reading.
> 
> For example reading of 10 mapsegments, each a blob of 2MB is just 200ms in
> total, including decompression.
> 
> But why is writing of the same data so slow?
> 
> The same 10 mapsegments needs 6000ms just for the fldTexture.WriteData(b).
> 
> I created the table like this:
> 
>    Dim s As String = "CREATE TABLE ""map_data"" ( " & _
>                           """idx_db"" ULLONG  NOT NULL UNIQUE INDEXED," & _
>                           """idx_level"" BYTE  NOT NULL INDEXED," & _
>                           """texture"" BLOB (1024) COMPRESSED ); "
>    mDatabase.SqlExecute(s)
> 
> 
> A larger segment-size does not change the time for writing.
> When I create the field without compression its faster, but still takes
> 3000ms.

Well, I think it is know that

A) WRITE is slower than READ even for HDD.

B) COMPRESSION is slower of decompression.
    you can easy see this in any archivator.

May be try to set less compression level. Will be faster but size little
bigger


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]