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
