2005/6/28, Tom Lane <[EMAIL PROTECTED]>: > Jean-Max Reymond <[EMAIL PROTECTED]> writes: > > I have a stored procedure written in perl and I doubt that perl's > > garbage collector is working :-( > > after a lot of work, postmaster has a size of 1100 Mb and I think > > that the keyword "undef" has no effects. > > Check the PG list archives --- there's been previous discussion of > similar issues. I think we concluded that when Perl is built to use > its own private memory allocator, the results of that competing with > malloc are not very pretty :-(. You end up with a fragmented memory > map and no chance to give anything back to the OS.
thanks Tom for your advice. I have read the discussion but a small test is very confusing for me. Consider this function: CREATE FUNCTION jmax() RETURNS integer AS $_$use strict; my $i=0; for ($i=0; $i<10000;$i++) { my $ch = "0123456789"x100000; my $res = spi_exec_query("select * from xdb_child where doc_id=100 and ele_id=3 "); } my $j=1;$_$ LANGUAGE plperlu SECURITY DEFINER; ALTER FUNCTION public.jmax() OWNER TO postgres; the line my $ch = "0123456789"x100000; is used to allocate 1Mb. the line my $res = spi_exec_query("select * from xdb_child where doc_id=100 and ele_id=3 limit 5"); simulates a query. without spi_exec_quer, the used memory in postmaster is a constant. So, I think that pl/perl manages correctly memory in this case. with spi_exec_query, postmaster grows and grows until the end of the loop. Si, it seems that spi_exec_query does not release all the memory after each call. For my application (in real life) afer millions of spi_exec_query, it grows up to 1Gb :-( -- Jean-Max Reymond CKR Solutions Open Source Nice France http://www.ckr-solutions.com ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly