I'm trying to compile PG on Ubuntu in order to hack tuplesort.c code
I just downloaded and unpacked the source code and red README and INSTALL files.
I'm going to
./configure --enable-debug --enable-cassert --enable-depend
then I would
make
make install
Can I improve something adding some missing option/command to the above steps?
Where and how to apply the TRACE_SORT option?
Any other useful options?
Sorry, I'm not so expert on Linux/PostgreSQL/gcc/make etc etc.
Thanks for your time.
Date: Mon, 26 Nov 2007 11:09:54 -0800
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
CC: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Replacement Selection
[EMAIL PROTECTED] wrote:
I also implemented
Replacement Selection (RS) so if I'm able to integrate my RS I hope I
would be able to integrate the others too.
The existing code implements RS. Tom asked you to describe what improvements
you hope to make; I'm confident that he already understands how to implement
RS. :-)
**
Why don't you compile with TRACE_SORT enabled and watch the log output.
The function in tuplesort.c that you should start with is puttuple_common().
in puttuple_common(), the transition from an internal to external sort is
performed at the bottom of the TSS_INITIAL case in the main switch
statement. The function dumptuples() heapifies the in-core tuples (divides
the in-core tuples into initial runs and then advances the state to
TSS_BUILDRUNS). All subsequent tuples will hit the TSS_BUILDRUNS case and
will insert tuples into the heap; emitting tuples for the current run as it
goes.
I recommend you run the code in the debugger on a external-sorting query:
watch two or three tuples go into the heap and you'll get the idea.
The top of the heap is at state-memtuples[0] the heap goes down from there.
New tuples are added there and the heap is adjusted (Using the
tuplesort_heap_siftup() function).
-Tim
_
Express yourself instantly with MSN Messenger! Download today it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
