LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #1   Report Post  
Posted to microsoft.public.excel.programming
external usenet poster
 
Posts: 28
Default very high cpu/ram usage: many Excel/SQL Server ADO return-trips

Hi there

I'm making many round-trips to SQL Server from Excel using a VBA module and
an ADO connection. Since I'm connecting to only one SQL Server database, I
keep the same connection open throughout the procedure, using the
"conn.Close( )" and "Set conn = Nothing" statements only at the very end.

Then, using this connection, I iterate through each record in the database
creating a new recordset each time, i.e. "For i = 1 to 117394 | Set rs =
conn.Execute( , ) | ... | Next i", etc. I know this must sound inefficient
and slow, which it is, but I find it's even slower to pull a single
recordset containing all records up-front and then loop through this using
"Do While Not rs.EOF | ... | rs.MoveNext | Loop", since the database is very
large (about 9GB), there are many complex joins between the tables (at least
40), and the requisite VBA code is a bit unwieldy to say the least.

I encounter the following problem: for the first few thousand records the
procedure is zippy, but thereafter the performance tapers off, becoming
progressively slower and slower; CPU usage rises to 100% and Excel ends up
absorbing all the available RAM and paging file memory. I presume that I am
not releasing objects from memory, though within the loop that creates a
recordset I also give the statements "rs.Close( )" and "Set rs = Nothing".

Can you shed any light on where the memory-intensive part of the operation
is, or perhaps I'm way off track.

Best regards
Loane



 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How do I create an xls for an OTR driver including trips and fees? wolfchild Excel Discussion (Misc queries) 2 March 18th 10 10:30 PM
Excel 2007 high cpu usage, format cell, wrap text Michael S. Wall Excel Discussion (Misc queries) 9 October 16th 09 07:34 PM
Return a High Number Anthony Excel Worksheet Functions 6 February 25th 08 03:25 PM
attn: shirley - genuinely high quality news server - mag - (1/1) ban Excel Worksheet Functions 0 February 3rd 07 04:31 AM
CPU Usage very high for Excel viewer WCNW Excel Discussion (Misc queries) 0 October 18th 05 12:37 AM


All times are GMT +1. The time now is 12:24 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 ExcelBanter.
The comments are property of their posters.
 

About Us

"It's about Microsoft Excel"