Autovacuum Error Message out of memory - Mailing list pgsql-general

Hello everyone

I have the following error in my postgres-log:
************************************************** ***********
TopMemoryContext: 95584 total in 8 blocks; 4824 free (11 chunks); 90760 used
Operator class cache: 8192 total in 1 blocks; 3848 free (0 chunks); 4344 used
TopTransactionContext: 24576 total in 2 blocks; 23960 free (15 chunks); 616 used
TOAST to main relid map: 24576 total in 2 blocks; 9960 free (5 chunks); 14616 used
AV worker: 24576 total in 2 blocks; 19984 free (9 chunks); 4592 used
Autovacuum Portal: 8192 total in 1 blocks; 8176 free (0 chunks); 16 used
Vacuum: 8192 total in 1 blocks; 8136 free (0 chunks); 56 used
smgr relation table: 8192 total in 1 blocks; 2816 free (0 chunks); 5376 used
TransactionAbortContext: 32768 total in 1 blocks; 32752 free (0 chunks); 16 used
Portal hash: 8192 total in 1 blocks; 3912 free (0 chunks); 4280 used
PortalMemory: 0 total in 0 blocks; 0 free (0 chunks); 0 used
Relcache by OID: 8192 total in 1 blocks; 3376 free (0 chunks); 4816 used
CacheMemoryContext: 405552 total in 19 blocks; 34864 free (1 chunks); 370688 used
pg_toast_75308101_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_index_indrelid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_opclass_am_name_nsp_index: 1024 total in 1 blocks; 192 free (0 chunks); 832 used
pg_foreign_data_wrapper_name_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_enum_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_class_relname_nsp_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_foreign_server_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_statistic_relid_att_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_cast_source_target_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_language_name_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_authid_oid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_amop_fam_strat_index: 1024 total in 1 blocks; 88 free (0 chunks); 936 used
pg_index_indexrelid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_ts_template_tmplname_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_config_map_index: 1024 total in 1 blocks; 192 free (0 chunks); 832 used
pg_opclass_oid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_foreign_data_wrapper_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_auth_members_member_role_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_dict_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_conversion_default_index: 1024 total in 1 blocks; 128 free (0 chunks); 896 used
pg_operator_oprname_l_r_n_index: 1024 total in 1 blocks; 128 free (0 chunks); 896 used
pg_trigger_tgrelid_tgname_index: 1024 total in 1 blocks; 240 free (0 chunks); 784 used
pg_enum_typid_label_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_config_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_user_mapping_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_opfamily_am_name_nsp_index: 1024 total in 1 blocks; 192 free (0 chunks); 832 used
pg_type_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_aggregate_fnoid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_constraint_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_rewrite_rel_rulename_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_parser_prsname_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_config_cfgname_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_parser_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_operator_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_namespace_nspname_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_ts_template_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_amop_opr_fam_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_ts_dict_dictname_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_auth_members_role_member_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_type_typname_nsp_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_opfamily_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_class_oid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_proc_proname_args_nsp_index: 1024 total in 1 blocks; 192 free (0 chunks); 832 used
pg_attribute_relid_attnum_index: 1024 total in 1 blocks; 240 free (0 chunks); 784 used
pg_proc_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_language_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_namespace_oid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_database_oid_index: 1024 total in 1 blocks; 304 free (0 chunks); 720 used
pg_amproc_fam_proc_index: 1024 total in 1 blocks; 88 free (0 chunks); 936 used
pg_authid_rolname_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_foreign_server_name_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_attribute_relid_attnam_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_conversion_oid_index: 1024 total in 1 blocks; 344 free (0 chunks); 680 used
pg_user_mapping_user_server_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
pg_conversion_name_nsp_index: 1024 total in 1 blocks; 280 free (0 chunks); 744 used
MdSmgr: 8192 total in 1 blocks; 7648 free (0 chunks); 544 used
LOCALLOCK hash: 8192 total in 1 blocks; 3912 free (0 chunks); 4280 used
Timezones: 79320 total in 2 blocks; 5968 free (0 chunks); 73352 used
ErrorContext: 8192 total in 1 blocks; 8176 free (0 chunks); 16 used
2011-02-18 16:33:46.262 CET [2068:1] @ FEHLER: Speicher aufgebraucht
2011-02-18 16:33:46.262 CET [2068:2] @ DETAIL: Fehler bei Anfrage mit Größe 893716290.
************************************************** ***********

DB is running on Windows 2008 R2 with 24Gb Ram (Dedicated DB Server). The error seems to be a Autovacuum problem. DB Version is 8.4.6.

My primary config-changes are:

#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
max_connections = 500

#------------------------------------------------------------------------------
# RESOURCE USAGE (except WAL)
#------------------------------------------------------------------------------
shared_buffers = 256MB
temp_buffers = 128MB
work_mem = 64MB
maintenance_work_mem = 1024MB
vacuum_cost_delay = 100ms
vacuum_cost_page_hit = 4
vacuum_cost_limit = 150

#------------------------------------------------------------------------------
# WRITE AHEAD LOG
#------------------------------------------------------------------------------
wal_buffers = 128kB
checkpoint_segments = 100
checkpoint_timeout = 15min

#------------------------------------------------------------------------------
# AUTOVACUUM PARAMETERS
#------------------------------------------------------------------------------
autovacuum = on
log_autovacuum_min_duration = -1
autovacuum_max_workers = 3
autovacuum_naptime = 5min
autovacuum_vacuum_threshold = 600
autovacuum_analyze_threshold = 300
autovacuum_vacuum_scale_factor = 0.3
autovacuum_analyze_scale_factor = 0.15
autovacuum_vacuum_cost_delay = -1

Any idea?