Does it make a differance?

Results 1 to 3 of 3

Thread: Does it make a differance?

  1. #1
    Join Date
    Dec 1969

    Default Does it make a differance?

    I have a few web ASP scripts that look at information from an SQL 2000 database. Now on some of those scripts they only look at one or 2 of the columns from a table. Is there a difference in performance when I pull all the columns or just the ones it looks at?

  2. #2
    Join Date
    Dec 1969

    Default Yes (eop)


  3. #3
    Join Date
    Dec 1969

    Default It can make a *huge* difference

    Depending on which columns you are omitting. Think about it: SQL Server is running in another process (could even be on another machine). You send this request "across the wire" [the "wire" might stay entirely in one machine or might not, but in any case the request has to be "marshalled" from one program to the other]. SQL Server responds by sending back info, again across the wire. It&#039;s not like the data is just sitting in a chunk of memory waiting for either some or all of it to be used. It has to be pulled from the on-disk files into buffers and then from the buffers into a format usable by ODBC or OLD DB and then converted from that form to Variants that can be used by ADO and VBS. And likely there is at least one more conversion in there. And at least one or two movements of the data, even without conversion. The more data to move, the slower.<BR><BR>

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts