performance-tuning

Improving WPF memory usage

Hello developers Is there any way you can store the UI state to disk when a WPF form has been minimised. I have a complex GUI with few Tab Controls and it consumes quite a bit of memory which is kept allocated when the application is not active. I was hoping one of you may have got this working along the lines (or similar) Application...

PL/SQL profiler missing data

We are using pl/sql profiler to collect metrics. We noticed that on one of the environment the plsql_profiler_runs table is populated with the total execution time but the finer details that gets collected in the table plsql_profiler_data is missing. Any idea why this would be happening? We do use dbms_profiler.flush_data() before stopp...

Is there a PHP benchmark that meets these specific criteria?

The actual question at the bottom... first some background info: I'm working on a tool which converts PHP code to Scala. As one of the finishing touches, I'm in need of a really good (er, somewhat biased) benchmark. By dumb luck my first benchmark attempt was with some code which uses bcmath extensively, which unfortunately is 1000x sl...

After writing SQL statements in MySQL, how to measure the speed / performance of them?

I saw something from an "execution plan" article: 10 rows fetched in 0.0003s (0.7344s) (the link: http://explainextended.com/2009/09/18/not-in-vs-not-exists-vs-left-join-is-null-mysql/ ) How come there are 2 durations shown? What if I don't have large data set yet. For example, if I have only 20, 50, or even just 100 records, I can...

Does the @inline annotation in Scala really help performance?

Or does it just clutter up the code for something the JIT would take care of automatically anyway. ...

Is count(*) really expensive ?

I have a page where I have 4 tabs displaying 4 different reports based off different tables. I obtain the row count of each table using a select count(*) from <table> query and display number of rows available in each table on the tabs. As a result, each page postback causes 5 count(*) queries to be executed (4 to get counts and 1 for ...

Does it make sense to create index on field with less changeability ?

I heard opinion that it make no sense to create indexes when field has less changeability. Eg if it stores only A,B,C,D values then there wouldn't be benefit of having such index, and further more SQL server will not use it at all when executing query. I wonder your opinion on that matter? EDIT Sample usage Select * FROM Table WHERE ...

Python performance improvement request for winkler

I'm a python n00b and I'd like some suggestions on how to improve the algorithm to improve the performance of this method to compute the Jaro-Winkler distance of two names. def winklerCompareP(str1, str2): """Return approximate string comparator measure (between 0.0 and 1.0) USAGE: score = winkler(str1, str2) ARGUMENTS: str1 The ...

Sql serve Full Text Search with Containstable is very slow when Used in JOIN!

Hello, I am using sql 2008 full text search and I am having serious issues with performance depending on how I use Contains or ContainsTable. Here are sample: (table one has about 5000 records and there is a covered index on table1 which has all the fields in the where clause. I tried to simplify the statements so forgive me if there ...

Is my understanding of "select distinct" correct?

We recently discovered a performance problem with one of our systems and I think I have the fix but I'm not certain my understanding is correct. In simplest form, we have a table blah into which we accumulate various values based on a key field. The basic form is: recdate date rectime time system varchar(20) count integer ac...

Writing cfquery inside cfoutput tag ?

I am writing the cfquery inside the cfoutput tag. It can be written outside the cfoutput tag. My question here is do we have any performance issues if we write the cfquery inside the cfoutput ? ...

Flash causing jerky javascript animations

Hi Guys, I'm developing a site which has a flash background playing a small video loop scaled to fill the whole background. Over the top I have a number of HTML elements which are animated using javascript. The problem I am having is that (predominantly in FF, but also in others to a lesser degree) the flash seems to be causing my javas...

Project Performance Evaluation and Finding Weak Areas

I'm working in J2EE web project, which has lots of Java, SQL scripts, JS, AJAX stuff. Its been 5 years for project still running fine. I have assigned with work of performance evaluation on the project as there might be some memory usage issues, DB fetching logic delays and other similar weak performance areas. From where should I begin...

Python faster way to read fixed length fields form a file into dictionary

I have a file of names and addresses as follows (example line) OSCAR ,CANNONS ,8 ,STIEGLITZ CIRCUIT And I want to read it into a dictionary of name and value. Here self.field_list is a list of the name, length and start point of the fixed fields in the file. What ways are there to speed up this method? (python 2.6) de...

SQL Server Express performance issue

Hi folks ! I know my questions will sound silly and probably nobody will have perfect answer but since I am in a complete dead-end with the situation it will make me feel better to post it here. So... I have a SQL Server Express database that's 500 Mb. It contains 5 tables and maybe 30 stored procedure. This database is use to store a...

How can i test my DB speed? (Learning)

I have design a database. Theres no columns with indexing, nor any code for optimizing. I am positive i should index certain columns since i search them a lot. My question is HOW do i test if any part of my database will be slow? ATM I am using sqlite and i will be switching to either MS Sql or MySql based on my host provider. Will crea...

Oracle EXECUTE IMMEDIATE changes explain plan of query.

I have a stored procedure that I am calling using EXECUTE IMMEDIATE. The issue that I am facing is that the explain plan is different when I call the procedure directly vs when I use EXECUTE IMMEDIATE to call the procedure. This is causing the execution time to increase 5x. The main difference between the plans is that when I use exec...

Design a SMTP server for High Volume Outbound Email

We are developing an application which will require to send around 30 outbound emails per second. We have a server running SMTP but this machine in cloud hosted and I do not have any idea what kind of configuration will I require to support such a load. I do not even know if this load is considered to be average or high. Do i need to do ...

Will creating index help in this case

I'm still a learning user of SQL-SERVER2005. Here is my table structure CREATE TABLE [dbo].[Trn_PostingGroups]( [ControlGroup] [char](5) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, [PracticeCode] [char](5) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL, [ScanDate] [smalldatetime] NULL, [DepositDate] [smalldatetime] NULL, [NameOfFile]...

Followup: Table Per Concrete Type Performance/Scaling

This is a followup/post question to another question; as I have discovered a solution that has led me to a new problem. http://stackoverflow.com/questions/2802902/classes-to-entities-like-class-inheritence-problems We're building this game system, so to speak; and I am using Table Per Concrete Type concept to perform inheritance modeli...