[Mono-bugs] [Bug 79707][Nor] New - DataTable.Select is linear

bugzilla-daemon at bugzilla.ximian.com bugzilla-daemon at bugzilla.ximian.com
Fri Oct 20 13:16:58 EDT 2006

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Changed by prensing at cimetrics.com.


--- shadow/79707	2006-10-20 13:16:58.000000000 -0400
+++ shadow/79707.tmp.9604	2006-10-20 13:16:58.000000000 -0400
@@ -0,0 +1,50 @@
+Bug#: 79707
+Product: Mono: Class Libraries
+Version: 1.1
+OS Details: Fedora Core 5
+Status: NEW   
+Priority: Normal
+Component: Sys.Data
+AssignedTo: mono-bugs at ximian.com                            
+ReportedBy: prensing at cimetrics.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+Summary: DataTable.Select is linear
+Please fill in this template when reporting a bug, unless you know what you
+are doing.
+Description of Problem:
+The DataTable.Select() method is behaving as an Order N process. 
+I wrote a small program which fills a table with N rows. I then use Select
+to fetch each item. The program timing goes as N^2 (ie N queries, each
+taking O(N) time).
+On Linux with Mono, for 10,000 rows, the program takes 141 seconds. On
+Windows with .NET (pretty much the same machine), the same program takes
+0.4 seconds.
+This is a repeat of bug 77691. The memory growth was fixed, but the speed
+is still atrocious.
+Steps to reproduce the problem:
+1. Load Datatable with lots of rows
+2. Call Select() many times
+3. Watch the clock
+Actual Results:
+Speed is very poor.
+Expected Results:
+The library should build an index on the column and use that for subsequent
+How often does this happen? 
+Additional Information:

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