Hi geniuses,
I have a core database question in MS Access and SQL Server.
Assume the following table in MS Access or SQL Server:
Employees table:
EmpID, Name, Hiredate, Photo;
and the following query:
"SELECT EmpID, Name, Hiredate FROM Employees;"
The question is, "does the blob object (Photo) affect the performance of the query even when not included in the select statement?"
I mean, will I gain some additional performance when separating the blob fields to another table?
Thanks for the answer.
You should ask this question in the ms - sql forums,
From my point of view it should not, and i do not have an idea of the implementation of any of the ms databases till now,
anyone has related notes please direct on this, looks interesting.
|||if you don′t select the image / binary column there should be no performance issue.
Jens K. Suessmeyer.
http://www.sqlserver2005.de
|||Unless you have specifically created the table with the image/binary data 'in the row', it is NOT stored in the table.
sp_tableoption N'MyTable', 'large value types out of row', 'ON'
is the default. In the table, there is only a 'pointer' in the actual location.
In any case, NOT including the image/binary field in the SELECT statement will definintely enhance performance. But there will be little effect noticed by moving the image/binary pointer (16 bytes) to another table.
No comments:
Post a Comment