Re: [HACKERS] Multi CPU Queries - Feedback and/or suggestions wanted!

2008-10-21 Thread Myron Scott
is available if it's of any help. http://weaver2.dev.java.net Myron Scott On Oct 20, 2008, at 11:28 PM, Chuck McDevitt wrote: There is a problem trying to make Postgres do these things in Parallel. The backend code isn’t thread-safe, so doing a multi-thread implementation requires

Re: [HACKERS] Support Parallel Query Execution in Executor

2006-04-11 Thread Myron Scott
On Tue, 2006-04-11 at 07:47, Myron Scott wrote: > client > or additional processing. Am I missing something in this analysis? > > I've attached my dtrace script. > To answer my own question, I suppose my processors are relatively slow compared to most

Re: [HACKERS] Support Parallel Query Execution in Executor

2006-04-11 Thread Myron Scott
27;ing the attributes for transmission back to the client or additional processing. Am I missing something in this analysis? I've attached my dtrace script. Myron Scott #!/usr/sbin/dtrace -s pid$1::ExecInitSeqScan:entry { ts = timestamp; vts = vtimestamp; timeon = 1

Re: [HACKERS] Support Parallel Query Execution in Executor

2006-04-09 Thread Myron Scott
On Apr 9, 2006, at 9:26 AM, Martijn van Oosterhout wrote: On Sun, Apr 09, 2006 at 08:23:36AM -0700, Myron Scott wrote: This is the part I'm curious about - is this using the shared_buffers region in a circular buffer fashion to store pre-fetched pages? Yes. That is basically what the

Re: [HACKERS] Support Parallel Query Execution in Executor

2006-04-09 Thread Myron Scott
On Apr 8, 2006, at 10:29 PM, Luke Lonergan wrote: Myron, First, this sounds really good! On 4/8/06 9:54 PM, "Myron Scott" <[EMAIL PROTECTED]> wrote: I added a little hack to the buffer code to force pages read into the buffer to stay at the back of the free buffer list

Re: [HACKERS] Support Parallel Query Execution in Executor

2006-04-08 Thread Myron Scott
e in total time using the delegated scan. A very crude, simple test but I think it shows some promise. I know I used threads but you could probably just as easily use a slave process and pass ItemPointers via pipes or shared memory. Thanks, Myron Scott ---

Re: [HACKERS] Threads vs Processes

2003-09-25 Thread Myron Scott
hout affecting other parts of the codebase. Myron Scott ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]

Re: Discontent with development process (was:Re: [HACKERS] pgaccess - the discussion is over)

2002-05-14 Thread Myron Scott
eeds to be a hashtable --- you wouldn't ever be doing >lookups in it, would you? Just a simple list of things-to-copy ought to >do fine. > > I'm thinking in a threaded context where a method may need to lookup a global that is not passed in. But for copying

Re: Discontent with development process (was:Re: [HACKERS] pgaccess - the discussion is over)

2002-05-14 Thread Myron Scott
own globals structure and register them with the hashtable. This would not impact readablity and make the gobal environment easy to copy. IMHO, this is possible with minimal performance impact. Myron Scott [EMAIL PROTECTED] ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html

Re: [HACKERS] Spinlock performance improvement proposal

2001-09-26 Thread Myron Scott
> But note that Myron did a number of things that are (IMHO) orthogonal yes, I did :) > to process-to-thread conversion, such as adding prepared statements, > a separate thread/process/whateveryoucallit for buffer writing, ditto > for vacuuming, etc. I think his results cannot be taken as in

Re: [HACKERS] Spinlock performance improvement proposal

2001-09-26 Thread Myron Scott
that process. This was and seems to still be the major drawback to using threads. Myron Scott [EMAIL PROTECTED] ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html

Re: [HACKERS] Using Threads

2001-02-06 Thread Myron Scott
multi-threaded got closer to 7.1 for inserts. I haven't tested other other types of commands yet. Myron Scott [EMAIL PROTECTED]

Re: [HACKERS] Using Threads?

2001-02-05 Thread Myron Scott
java side of the JNI interface yet but the C++ side is there. It's still not stable but it is much better than the last. Myron Scott [EMAIL PROTECTED]

Re: [HACKERS] Using Threads?

2001-01-02 Thread Myron Scott
hread low and commit as many transactions as possible simulateously. Maybe, I should rethink this. As for client threads, that is managed by TAO and I haven't really played with that configuration. Myron Scott [EMAIL PROTECTED]

Re: [HACKERS] Using Threads?

2001-01-02 Thread Myron Scott
Karel Zak wrote: > On Tue, 2 Jan 2001, Myron Scott wrote: > > >> spinlocks rewritten to mutex_ >> locktable uses sema_ >> some cond_ in bufmgr.c > > > Interesting, have you some comperation between IPC PostgresSQl anf > your thread based P

Re: [HACKERS] Using Threads?

2001-01-01 Thread Myron Scott
spinlocks rewritten to mutex_ locktable uses sema_ some cond_ in bufmgr.c Myron Karel Zak wrote: > On Mon, 1 Jan 2001, Myron Scott wrote: > > >> For anyone interested, >> >> I have posted my multi-threaded version of PostgreSQL here. >> >> http://www

Re: [HACKERS] Using Threads?

2001-01-01 Thread Myron Scott
For anyone interested, I have posted my multi-threaded version of PostgreSQL here. http://www.sacadia.com/mtpg.html It is based on 7.0.2 and the TAO CORBA ORB which is here. http://www.cs.wustl.edu/~schmidt/TAO.html Myron Scott [EMAIL PROTECTED]

Re: [HACKERS] Using Threads?

2000-12-04 Thread Myron Scott
I would love to distribute this code to anybody who wants it. Any suggestions for a good place? However, calling the work a code redesign is a bit generous. This was more like a brute force hack. I just moved all the connection related global variables to a thread local "environment variable"

Re: [HACKERS] Using Threads?

2000-12-04 Thread Myron Scott
to generate threadsafe code as well. I use it as a linked library with my own fe<->be protocol. This ended up being much much more than I bargained for and looking back would probably not have tried had I known any better. Myron Scott On Mon, 27 Nov 2000, Junfeng Zhang wrote: >