Hi In a stored procedure (which has a date parameter named 'paramDate' ) I have a query like this one select id, name from customer where period_aded = to_char(paramDate,'mm/yyyy') will Oracle convert paramDate to string for each row? I was sure that Oracle wouldn't but I was told that Oracle will. In fact I thought that if the param...
I have a DB table which consists of 2.5 billion records. There are duplicates to the tune of 11 million. Which is the fastest way to delete these 11 million records? ...
Hi, What free tools do you know that can be used for tuning multithreaded applications? If there are any. ...
Hi, I run a Mysql 5.0.26 (Myisam tables). To improve the search results, I am doing some fine tuning. I have noticed that the characters considered as word characters do not match the constraints of (Swiss-) French... and English too. :( I would like to: ADD the character "-" in the "word character" list REMOVE the character "'" from...
I recently compared Windows Vista internal Webdav client (mini-redirector) to WebDrive, because Vista seemed to be very slow. I found that Windows Vista uses only 1 HTTP connection and needs 9 requests on average to upload one file, while WebDrive uses 2 HTTP connections for uploading by default (can be configured to use more), and need...
I've got these two queries: SELECT SELECT NamesRecord.NameID, NamesRecord.FulfillmentAddressID NameFulfillmentAddressID, ContractRecord.FulfillmentAddressID, ContractRecord.BillingAddressId FROM Magnet.dbo.ContractRecord ContractRecord INNER JOIN Magnet.dbo.NamesRecord NamesRecord ON NamesRecord.NameId = ContractRecord.DonorId WHERE ...
We need to read and count different types of messages/run some statistics on a 10 GB text file, e.g a FIX engine log. We use Linux, 32-bit, 4 CPUs, Intel, coding in Perl but the language doesn't really matter. I have found some interesting tips in Tim Bray's WideFinder project. However, we've found that using memory mapping is inherent...
Here's the setup: I have an algorithm that can succeed or fail. I want it to succeed with highest probability possible. Probability of success depends on some parameters (and some external circumstances): struct Parameters { float param1; float param2; float param3; float param4; // ... }; bool RunAlgorithm (const Parameters...
Over the past year I've made huge improvements in my application's Java heap usage--a solid 66% reduction. In pursuit of that, I've been monitoring various metrics, such as Java heap size, cpu, Java non-heap, etc. via SNMP. Recently, I've been monitoring how much real memory (RSS, resident set) by the JVM and am somewhat surprised. ...
Hello, Firebug is awesome in reporting the relative time when an HTTP request was made with respect to the 'DomContentLoaded' and 'load' time. However, once the 'load' event occurs (seen by the red line on the timeline), the requests thereafter do not have any information about how later they occurred with respect to the two events. To...
SELECT DISTINCT group_id , supplier_id , supplier_name , site_division_id , site_division_name FROM view_supplier_site WHERE supplier_id IN (SELECT DISTINCT supplier_id FROM view_supplier WHERE YEAR IN (2008, 2009) AND received_quantity > 0...
I have been tasked with improving the performance of a slow running process which updates some data in a PostGres 8.3 database (running on Solaris, updates are driven by Perl 5.8 scripts through SOAP). About 50% of the time consumed I have very little control over so tuning my 50% is quite important. There are usually about 4,500,000 r...
I have heard several people claiming that you can not scale the JVM heap size up. I've heard claims of the practical limit being 4 gigabytes (I heard an IBM consultant say that), 10 gigabytes, 32 gigabytes, and so on... I simply can not believe any of those numbers and have been wondering about the issue now for a while. So, I have thr...
What are the means to schedule automatic "analyze tables". Is it possible to request an automatic "analyze tables" when a lot of data change througt insert and deletes? What are the means to parametrize the automatic analyze tables process, i.e. to set rules when it should be triggered. ...
I want to know few things about ASP.NET MVC with NHibernate. Is NHibernate the best ORM used with ASP.NET MVC? If so, will NHibernate slow down the application? What can be done to improve performance of an ASP.NET MVC application with NHibernate? ...
I've been having it analyze my queries and pushing the recommendations for some time now. Are there any potential pitfalls with doing this? Would I be better of creating my own indexes by hand? ...
I'm in the process of tuning a pet project of mine to improve its performance. I've already busted out the profiler to identify hotspots but I'm thinking understanding Pythons performance characteristics a little better would be quite useful going forward. There are a few things I'd like to know: How smart is its optimizer? Some moder...
Hello, I have been trying to find a better Tokyo Cabinet (or Tokyo Tyrant) configuration for my application, but I don't know exactly how. I know what some parameters mean but I want to have a fine tuning control, so I need to know the impact of each one. The Tokyo documentation is really good but not at this point. Does any one can hel...
We have two tables like so: Event id type ... a bunch of other columns ProcessedEvent event_id process There are indexes defined for Event(id) (PK) ProcessedEvent (event_id, process) The first represents events in an application. The second represents the fact that a certain event got processes by a certain...
We have currently a Postgres database with a 100 of tables 20 of them with more than 5 000 000 rows, the master DB server runs on Debian 32MB RAM 8 Processors. Additionaly to the master DB we have a Slave DB replicated using Slony. Our application uses Java and Hibernate framework for SQL query, c3p0 as connection pool. Our problem is...