Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread Christoph Läubrich
Can you refer to a document where it describes: > A caching thread pool does more than reducing the overhead of allocating threads. > It reduces the cost of idle threads to zero (as opposed to keeping their stack around at a price of up to 16GB memory). From the javadoc I can't see that this

Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread cowwoc
Inlined replies below. On 18/02/2012 9:54 AM, Christoph Läubrich wrote: A CachedThreadpool won't change anything here, it is only usefull if you have many*short living threads* because it reduces the overhead assosiated with *allocating* a thread. The Thread count is manly bound by the thr

Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread cowwoc
Not true. Take another look at his charts: * The default stack size for threads under 64-bit JVMs is 1MB. Source: http://www.oracle.com/technetwork/java/hotspotfaq-138619.html * At 64-bit with 512k stack (notice, this is smaller than the default) he is still limited to 32k threads an

use of csvread ignoring comments

2012-02-18 Thread h2
Hi I have a csv file in the format #Comment1 #Comment2 #Comment3 ID,NAME,LEVEL 1,JOHN,3 2,MIKE,4 . . One way of reading this might be to specify the columns in csvread as CSVREAD('test.csv', 'ID|NAME|LEVEL', 'charset=UTF-8 fieldSeparator=|') and use a 'where' clause when

Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread Noel Grandin
The latest versions of Java support 10s of thousands of threads. When they are idle the OS swaps out the memory pages and there is very little overhead. http://vanillajava.blogspot.com/2011/07/java-what-is-limit-to-number-of-threads.html http://stackoverflow.com/questions/2117072/java-thread-creat

Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread Christoph Läubrich
A CachedThreadpool won't change anything here, it is only usefull if you have many* short living threads* because it reduces the overhead assosiated with *allocating* a thread. The Thread count is manly bound by the threads stack size and the OS and not by the JVM itself. If the thread is really

Re: Support for thread-pools (log/lock-threads)

2012-02-18 Thread cowwoc
Thomas, My understanding is that idle threads (even if they are one per database) will eat up valuable memory. The last time I checked Java would only allow you to launch a few thousand threads (2000 or so). By introducing a thread pool you're allowing the user to run more databases but h