0006275: Very poor performance of JvMemoryData on large datasets - Project JEDI

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Severity

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Date Submitted

Last Update

0006275

[JEDI VCL] 00 JVCL Components

major

always

2014-04-22 17:42

2015-09-14 13:20

Reporter

bazilio

View Status

public

Assigned To

AHUser

Priority

normal

Resolution

fixed

Status

resolved

Product Version

Daily / GIT

Summary

0006275: Very poor performance of JvMemoryData on large datasets

Description

We have heavy application for TJvMemoryData. It have few dynamically JV memorydataset with 100-200 fields and 10-100 rows. During perfoformance tuning of our application we reached following strange behavior of TJvMemory. Direct access via TField of first fields is fast but access to last fields is very slow.
  After investigation I found that the

TJvMemoryData.FindFieldData(Buffer: Pointer; Field: TField): Pointer;
contains very suspicious code

var
  Index: Integer;
  DataType: TFieldType;
begin
  Result := nil;
  if Length(FCopyFromDataSetFieldDefs) > 0 then
    Index := FCopyFromDataSetFieldDefs[Field.Index]
  else
    Index := FieldDefList.IndexOf(Field.FullName);

IndexOf(Field.FullName)!!!!! instead of access through Field.Index/

I wrote very little patch to avoid this.
Test project attached.
Any comments?

Additional Information

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No tags attached.

Attached Files

JVMemoryDataTest.zip [^] (11,536 bytes) 2014-04-22 17:42

Relationships

Notes
(0020953) AHUser (developer) 2014-04-24 22:54	Using Field.Index won't work if you make the CalcField the first field because then Field.Index is off by one. But using "Field.FieldNo - 1" is the solution. I also made the Open and the CopyFromDataSet much faster. With the change to Field.FieldNo the FCopyFromDataSetFieldDefs array isn't necessary anymore. Solved in master branch.

Issue History
Date Modified	Username	Field	Change
2014-04-22 17:42	bazilio	New Issue
2014-04-22 17:42	bazilio	File Added: JVMemoryDataTest.zip
2014-04-24 22:54	AHUser	Note Added: 0020953
2014-04-24 22:54	AHUser	Status	new => resolved
2014-04-24 22:54	AHUser	Fixed in Version	=> Daily / GIT
2014-04-24 22:54	AHUser	Resolution	open => fixed
2014-04-24 22:54	AHUser	Assigned To	=> AHUser
2015-09-14 13:20	obones	Fixed in Version	Daily / GIT => 3.48

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