memory leak under heavy load? - Mailing list pgsql-general

hi
i think i've encountered a bug in postgresql 8.1.
yet - i'm not reallty info submitting it to -bugs, as i have no way to successfully redo it again.

basically
i have server, with dual opteron, 4g of memory, 2gb of swap. everything working under centos 4.2.

postgresql 8.1 compiled from sources using:
./configure \
    --prefix=/home/pgdba/work \
    --without-debug \
    --disable-debug \
    --with-pgport=5810 \
    --with-tcl \
    --with-perl \
    --with-python \
    --without-krb4 \
    --without-krb5 \
    --without-pam \
    --without-rendezvous \
    --with-openssl \
    --with-readline \
    --with-zlib \
    --with-gnu-ld

postgresql.conf looks like this (i removed commented lines):
listen_addresses = '*'       
max_connections = 250
superuser_reserved_connections = 10
password_encryption = on
shared_buffers = 50000           
temp_buffers = 1000           
max_prepared_transactions = 250       
work_mem = 10240           
maintenance_work_mem = 131072         
max_fsm_pages = 500000           
max_fsm_relations = 5000       
fsync = off               
wal_buffers = 100           
commit_delay = 1000           
commit_siblings = 5           
checkpoint_segments = 100       
effective_cache_size = 196608       
random_page_cost = 1.5           
default_statistics_target = 50       
log_destination = 'stderr'       
redirect_stderr = on           
log_directory = '/home/pgdba/logs/'       
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
log_rotation_age = 1440       
log_rotation_size = 502400       
log_min_duration_statement = 5000   
log_connections = on
log_duration = off
log_line_prefix = '[%t] [%p] <%u@%d> '           
log_statement = 'none'           
stats_start_collector = on
stats_command_string = on
stats_block_level = on
stats_row_level = on
stats_reset_on_server_start = on
autovacuum = off           
autovacuum_naptime = 60       
autovacuum_vacuum_threshold = 1000   
autovacuum_analyze_threshold = 500   
autovacuum_vacuum_scale_factor = 0.4   
autovacuum_analyze_scale_factor = 0.2   
check_function_bodies = on
lc_messages = 'en_US.UTF-8'           
lc_monetary = 'en_US.UTF-8'           
lc_numeric = 'en_US.UTF-8'           
lc_time = 'en_US.UTF-8'               
custom_variable_classes = 'plperl'       
plperl.use_strict = true

everything works nice,
but:
i run a loop of about 400 thousands inserts in transactions - two inserts in a transaction.
in totaal i had nearly 200 000 transactions - all very fast, and with no (or very little) time between them.
insert were made to 2 distinct tables, and (maybe that's important) about 99% failed because of "unique index violation".

what i say is that postmaster user started to "eat" memory.
it allocated *all* memory (both ram and swap), and then died.
load on the machine jumped to something around 20.

it is very strange for me. since next such run didn't break the postgres, but then - another one did.
i am unable to replay the scenario with 100% guarantee it will crash the backend.
as for the inserts - there were no triggers, no rules.
not even foreign keys. encodign is utf8.

is this something that anybody else encountered? what can i do to make it possible to fix the problem?

and yes - i know thay i should do copy instead of inserts, and bigger transactions, but i would like to have the problem fixed and not a workaround. actually i did a woraround for now and it works - every 100 transactions i disconnect and reconnect again. this way it works.

depesz