Re: Is my database now too big? - Mailing list pgsql-admin

Tom Lane wrote:
> Darren Reed <darrenr@fastmail.net> writes:
> > # /usr/pkg/bin/psql -U postgres template1
> > psql: FATAL:  out of memory
> > DETAIL:  Failed on request of size 20.
>
> I'm starting to think there is something very broken about your machine :-(.
> Have you run any hardware diagnostics on it lately?  The level of
> flakiness you're seeing starts to suggest bad RAM to me.
>

No, I haven't run any diagnostics.

But I'm not convinced the hardware is a problem because the flakiness
has only really
been a problem when I started doing more than just inserts and updates.
The table that
has shown the most problems (ifl) is a table of work to do, so I'm
inserting records,
doing a select of random items out of it and also deleting records (once
the work is
complete.)  Multiple processes can be trying to simultaneously be doing
all of these,
which should not be anything out of the ordinary.  Or maybe this
workload is just making
the database stress the hardware more?

> Anyway, the above error should have also produced a map of per-context
> memory usage in the postmaster log (ie, postmaster stderr).  If you
> could show us that, it might be revealing.
>

I think what you're referring to is this:

TopMemoryContext: 32768 total in 3 blocks; 7776 free (8 chunks); 24992 used
Operator class cache: 8192 total in 1 blocks; 4936 free (0 chunks); 3256
used
TopTransactionContext: 8192 total in 1 blocks; 7856 free (0 chunks); 336
used
MessageContext: 267378688 total in 43 blocks; 1768 free (45 chunks);
267376920 used
smgr relation table: 8192 total in 1 blocks; 3904 free (0 chunks); 4288 used
Portal hash: 8192 total in 1 blocks; 3912 free (0 chunks); 4280 used
PortalMemory: 8192 total in 1 blocks; 8176 free (1 chunks); 16 used
Relcache by OID: 8192 total in 1 blocks; 3896 free (0 chunks); 4296 used
CacheMemoryContext: 253952 total in 5 blocks; 11880 free (1 chunks);
242072 used
pg_attrdef_adrelid_adnum_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_type_typname_nsp_index: 1024 total in 1 blocks; 328 free (0 chunks);
696 used
pg_type_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_trigger_tgrelid_tgname_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_statistic_relid_att_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_auth_members_member_role_index: 1024 total in 1 blocks; 328 free (0
chunks);696 used
pg_auth_members_role_member_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_rewrite_rel_rulename_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_proc_proname_args_nsp_index: 1024 total in 1 blocks; 256 free (0
chunks); 768 used
pg_proc_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_operator_oprname_l_r_n_index: 1024 total in 1 blocks; 192 free (0
chunks); 832 used
pg_operator_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_opclass_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_opclass_am_name_nsp_index: 1024 total in 1 blocks; 256 free (0
chunks); 768 used
pg_namespace_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632
used
pg_namespace_nspname_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
pg_language_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_language_name_index: 1024 total in 1 blocks; 392 free (0 chunks); 632
used
pg_inherits_relid_seqno_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_index_indexrelid_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
pg_authid_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_authid_rolname_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
pg_database_datname_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
pg_conversion_oid_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
pg_conversion_name_nsp_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_conversion_default_index: 1024 total in 1 blocks; 192 free (0
chunks); 832 used
pg_class_relname_nsp_index: 1024 total in 1 blocks; 328 free (0 chunks);
696 used
pg_class_oid_index: 1024 total in 1 blocks; 392 free (0 chunks); 632 used
pg_cast_source_target_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_attribute_relid_attnum_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_attribute_relid_attnam_index: 1024 total in 1 blocks; 328 free (0
chunks); 696 used
pg_amproc_opc_proc_index: 1024 total in 1 blocks; 256 free (0 chunks);
768 used
pg_amop_opr_opc_index: 1024 total in 1 blocks; 328 free (0 chunks); 696 used
pg_amop_opc_strat_index: 1024 total in 1 blocks; 256 free (0 chunks);
768 used
pg_amop_opc_strat_index: 1024 total in 1 blocks; 256 free (0 chunks);
768 used
pg_aggregate_fnoid_index: 1024 total in 1 blocks; 392 free (0 chunks);
632 used
MdSmgr: 8192 total in 1 blocks; 8152 free (0 chunks); 40 used
LockTable (locallock hash): 8192 total in 1 blocks; 3912 free (0
chunks); 4280 used
Timezones: 47592 total in 2 blocks; 5968 free (0 chunks); 41624 used
ErrorContext: 8192 total in 1 blocks; 8176 free (0 chunks); 16 used
ERROR:  out of memory
DETAIL:  Failed on request of size 20.
TopMemoryContext: 32768 total in 3 blocks; 7776 free (8 chunks); 24992 used

The standout problem is the "MessageContext" count.

Darren