#28334 closed Cleanup/optimization (fixed)
contrib.postgresql overwhelms database with "select from pg_type" queries on each request
Reported by: | Igor Gumenyuk | Owned by: | Igor Gumenyuk |
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Component: | contrib.postgres | Version: | 1.11 |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Ready for checkin | |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description (last modified by )
On each newly created database connection django.contrib.postgresql
tries to register hstore type for this connection via connection_created
signal and register_hstore
function.
https://github.com/django/django/blob/master/django/contrib/postgres/apps.py#L20
https://github.com/django/django/blob/stable/1.11.x/django/contrib/postgres/signals.py#L16
Behind the scenes register_hstore
runs sql query to get oid
of hstore
type:
https://github.com/psycopg/psycopg2/blob/master/lib/extras.py#L885
This happens on every(!) request (unless persistent connections enabled)
SELECT t.oid, %s
FROM pg_type t JOIN pg_namespace ns
ON typnamespace = ns.oid
WHERE typname = 'hstore';
This is just huge overhead, since register_hstore
accepts oid
argument to avoid hitting database every call.
We have seen significant latency spikes because of this.
Possible solution would be to have configurable GET_HSTORE_OID_FUNC
in DATABASES->OPTIONS
setting which can be cached in any way.
This will also maintain backwards compatibility.
I can send patch for this if proposed solution is acceptable to be merged in master.
Change History (13)
comment:1 by , 7 years ago
Description: | modified (diff) |
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comment:2 by , 7 years ago
Triage Stage: | Unreviewed → Accepted |
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comment:3 by , 7 years ago
Owner: | set to |
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Status: | new → assigned |
comment:5 by , 7 years ago
Patch needs improvement: | set |
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There are test failures on the pull request.
comment:6 by , 7 years ago
Patch needs improvement: | unset |
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comment:8 by , 7 years ago
Needs tests: | set |
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comment:9 by , 7 years ago
Needs tests: | unset |
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comment:10 by , 7 years ago
Patch needs improvement: | set |
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comment:11 by , 7 years ago
Patch needs improvement: | unset |
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Triage Stage: | Accepted → Ready for checkin |
PR