Re: [HACKERS] Gsoc2012 Idea --- Social Network database schema

2012-03-18 Thread HuangQi
: On Sat, Mar 17, 2012 at 8:48 PM, HuangQi huangq...@gmail.com wrote: About the second topic, so currently TABLESAMPLE is not implemented inside Postgres? I didn't see this query before, but I googled it just now and the query seems very weird and interesting. http://www.fotia.co.uk/fotia

[HACKERS] Gsoc2012 Idea --- Social Network database schema

2012-03-17 Thread HuangQi
Hi, all I am a student of Computer Science and Applied Math in a university in Singapore. I'm planning to join Google Summer Code 2012 on PostgreSQL. It's quite an honor to join the postgresql hacker community. I have some postgresql developing experience while doing my school project. I'm

Re: [HACKERS] Gsoc2012 Idea --- Social Network database schema

2012-03-17 Thread HuangQi
(Sorry, Daniel. Forgot to cc pgsql-hackers.) Hi, Daniel Thanks a lot for your response. As I can see for now, in my FYP, as the acyclic schema has the property that it has a join tree. I will check how many join trees it has and investigate any best option for the RSN schema. If it does

Re: [HACKERS] [Hackers]Backend quey plan process

2011-06-28 Thread HuangQi
On 28 June 2011 22:36, Alvaro Herrera alvhe...@commandprompt.com wrote: Excerpts from HuangQi's message of lun jun 27 23:56:22 -0400 2011: BTW, which email system are you using to send to postgres mailing list? As you can keep the top-answering and maintain the title of your email

[HACKERS] [Hackers]Backend quey plan process

2011-06-27 Thread HuangQi
Hi, I've been tracing the data structure in the query plan process for a while. But then I found the data structure manipulation is really so confusing. Could some guy tell me where could I find any guide on how to figure out the process and data structure usage? Is there any good resource

[HACKERS] debugging tools inside postgres

2011-06-24 Thread HuangQi
Hi, I'm trying to debug a modification for the query planner. But I found it seems the data structure of my planned query is incorrect. I was trying to print out the data structure by use the p command in gdb which is quite inconvenient and takes time. May I know is there any embedded function

Re: [HACKERS] debugging tools inside postgres

2011-06-24 Thread HuangQi
2011/6/24 Shigeru Hanada shigeru.han...@gmail.com (2011/06/24 15:35), HuangQi wrote: Hi, I'm trying to debug a modification for the query planner. But I found it seems the data structure of my planned query is incorrect. I was trying to print out the data structure by use the p

Re: [HACKERS] debugging tools inside postgres

2011-06-24 Thread HuangQi
On 24 June 2011 23:21, Tom Lane t...@sss.pgh.pa.us wrote: Shigeru Hanada shigeru.han...@gmail.com writes: (2011/06/24 15:35), HuangQi wrote: I'm trying to debug a modification for the query planner. But I found it seems the data structure of my planned query is incorrect. I was trying

Re: [HACKERS] gdb with postgres

2011-06-07 Thread HuangQi
On 6 June 2011 21:57, Kevin Grittner kevin.gritt...@wicourts.gov wrote: HuangQi huangq...@gmail.com wrote: (gdb) b qp_add_paths_to_joinrel Breakpoint 1 at 0x1a6744: file joinpath.c, line 67. (gdb) attach 23903 If I enter c, gdb will directly finish executing this process and current

[HACKERS] gdb with postgres

2011-06-06 Thread HuangQi
Hi, I was using gdb to debug postgres. In order to debug the backend of running query, I start postgres first and use select * from pg_backend_pid() to ask for backend pid. Then I start gdb in another bash window with gdb postgres and attach the pid obtained above and set the breakpoint. Then I

Re: [HACKERS] gdb with postgres

2011-06-06 Thread HuangQi
Sorry, but recompile with this flag still doesn't work. On 6 June 2011 15:46, Pavan Deolasee pavan.deola...@gmail.com wrote: On Mon, Jun 6, 2011 at 1:13 PM, HuangQi huangq...@gmail.com wrote: Hi, I was using gdb to debug postgres. In order to debug the backend of running query, I start

Re: [HACKERS] gdb with postgres

2011-06-06 Thread HuangQi
If I enter c, gdb will directly finish executing this process and current query will finish. Furthermore, if I enter next query, gdb will not debug it and stay in continue status. On 6 June 2011 21:44, Robert Haas robertmh...@gmail.com wrote: On Mon, Jun 6, 2011 at 3:43 AM, HuangQi huangq

Re: [HACKERS] Hacking gram.y Error syntax error at or near MERGEJOIN

2011-06-03 Thread HuangQi
Thanks all for your ideas. Though wired, I reinstalled the Postgres and tried again. This error message disappears. The parser now works good. On 3 June 2011 01:13, Alvaro Herrera alvhe...@commandprompt.com wrote: Excerpts from HuangQi's message of jue jun 02 11:17:21 -0400 2011: Hi, thanks a

[HACKERS] Hacking gram.y Error syntax error at or near MERGEJOIN

2011-06-02 Thread HuangQi
Hi, I'm doing a hacking project which hacks the gram.y file and some other so that postgres can execute some query plan language to run a particular plan. I did some modifications and try run it. It compiled and installed successfully. But when I was trying to run a MergeJoin operation with

Re: [HACKERS] Hacking gram.y Error syntax error at or near MERGEJOIN

2011-06-02 Thread HuangQi
/src/include/parser/kwlist.h (depends on pg version) attention - keywords must be in alphabet order Regards Pavel Stehule 2011/6/2 HuangQi huangq...@gmail.com: Hi, I'm doing a hacking project which hacks the gram.y file and some other so that postgres can execute some query plan

Re: [HACKERS] Hacking gram.y Error syntax error at or near MERGEJOIN

2011-06-02 Thread HuangQi
, Heikki Linnakangas heikki.linnakan...@enterprisedb.com wrote: On 02.06.2011 15:16, Andrew Dunstan wrote: On 06/02/2011 03:28 AM, HuangQi wrote: Hi, I'm doing a hacking project which hacks the gram.y file and some other so that postgres can execute some query plan language to run