OpenEuphoria

Re: odbc resources

• Posted by Matt Lewis <matthewwalkerlewis at gmail.com> Nov 14, 2005
• 485 views

Craig Welch wrote:
> 
> I'm experimenting with odbc, with SQL Server behind it. I'm running a 
> program to read in a 30,000 record file line by line, and insert it into 
>   a table. (I know there are better ways of doing that, but it's a 
> learning exercise, both for odbc and SQL).
> 
> The data are the test records that come with the Tsunami database.
> 
> As the record count increases, the PC slows considerably, paging goes 
> through the roof, and eventually it's processing 4 transactions per 
> second. It starts at about 500 per second.
> 
> I put in an abend statement after 10,000 records. Here is a section of 
> the dump that makes me wonder:
> 
> handle_odbc = {9501740,9501900,-1}
>      handle_children = {
>                          {2},
>                          {3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
> 
> etc ... to the limit that ex.err will display.

> 
> Any thoughts?

OK, I think I know what's happening.  I'm not reusing the bookkeeping 
sequence handle_children properly.

Here's what the end of allocHandleODBC() should look like:

if parent then
    	-- try to reuse the children handles:
    	ix = find( -1, handle_children[parent] )
    	if not ix then
    		handle_children[parent] &= id
    	else
    		handle_children[parent][ix] = id
    	end if
        
        handle_parent[id] = parent
    end if
    
    return id
end function

...and the for-loop in the middle of freeHandleODBC():

for i = 1 to length( handle_children[id] ) do
        freeHandleODBC( handle_children[id][i] )
        
        -- mark this as ready for reuse
        handle_children[id][i] = -1
    end for

Matt Lewis