Index and Deleted

From: Anders Eriksson (anders.eriksson_at_morateknikutveckling.se)
Date: 01/24/05 

Date: Mon, 24 Jan 2005 08:22:50 +0100

Hello!

I'm using ADO from VC++ to read/write a dBase IV database.
Connection string: _T("Provider=Microsoft.Jet.OLEDB.4.0;User ID=Admin;Data
Source=tempdata;Mode=ReadWrite|Share Deny None;Extended Properties=dBASE
IV;Persist Security Info=False");

I have these columns:
 FIXNR STRING
 STATUS STRING
 DATA STRING (this is actually 120 different columns)

The database is indexed on FIXNR and on STATUS.

I then use this SQL to create a recordset
"SELECT * FROM TEMPDATA WHERE STATUS = 'Reg' ORDER BY FIXNR"

The application that creates the database and writes data to it is written
in Visual dBase and it will delete the record once I'm done with it.

If the database grows this strange thing will happen

If the records IS NOT deleted it will take men 1 second to open a recordset
and read the first record in the recordset.

If the records ARE deleted the same operation will take 350 seconds

The database contained 25000 records (140MB).

Anyone that understand why there is this difference in time??

// Anders

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