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Hello all, We recently moved our production database systems from a 9.4 running on a self-managed EC2 instance to 9.6.10 on Amazon’s AWS (same RAM, CPU). After the move, we’re finding that certain queries that we run
against a GIN full-text index have some occasionally very slow executions and I’m struggling to figure out what to do about it. I would be very grateful for any ideas!
Thanks, Scott The setup we have is a 32-core, 244 GB RAM primary with a same-sized read replica. The queries are running off the replica, but performance is roughly the same between the master and the replica.
Here’s a query that’s performing badly:
SELECT ls.location
AS locationId FROM location_search ls
WHERE ls.client = 83
AND search_field_tsvector @@ to_tsquery('9000:* &Smith''s:* &Mill:*')
AND ls.favorite = TRUE
LIMIT 1 The mean time for this query (and others like it) is about 900ms, but the std deviation is over 1000ms and the max is 11000ms.
The explain looks like this: Limit (cost=1516.25..1520.52 rows=1 width=223) (actual time=4506.482..4506.482 rows=0 loops=1) Buffers: shared hit=9073 -> Bitmap Heap Scan on location_search ls (cost=1516.25..1520.52 rows=1 width=223) (actual time=4506.480..4506.480 rows=0 loops=1) Recheck Cond: (search_field_tsvector @@ to_tsquery('9000:* &Smith''s:* &Mill:*'::text)) Filter: (favorite AND (client = 83)) Rows Removed by Filter: 8 Heap Blocks: exact=12 Buffers: shared hit=9073 -> Bitmap Index Scan on location_search_tsvector_idx (cost=0.00..1516.25 rows=1 width=0) (actual time=4506.450..4506.450 rows=12 loops=1) Index Cond: (search_field_tsvector @@ to_tsquery('9000:* &Smith''s:* &Mill:*'::text)) Buffers: shared hit=9061 Planning time: 0.240 ms Execution time: 4509.995 ms The table has about 30 million rows in it. The table and index definition are:
CREATE TABLE public.location_search ( id bigint NOT NULL DEFAULT nextval('location_search_id_seq'::regclass), person_location bigint, person bigint, client_location bigint, client bigint, location bigint, org_unit_id bigint, latitude numeric(10,7), longitude numeric(10,7), geofence numeric(10,7), address_line_one text COLLATE pg_catalog."default", address_line_two text COLLATE pg_catalog."default", city text COLLATE pg_catalog."default", state text COLLATE pg_catalog."default", postal_code text COLLATE pg_catalog."default", country text COLLATE pg_catalog."default", full_address text COLLATE pg_catalog."default", is_google_verified boolean, address_source text COLLATE pg_catalog."default", active boolean, name character varying(255) COLLATE pg_catalog."default", external_client_location_id character varying(500) COLLATE pg_catalog."default", custom_field_values hstore, location_tags hstore, legacy_location_id bigint, favorite boolean, search_field_tsvector tsvector ) WITH ( OIDS = FALSE ) TABLESPACE pg_default; CREATE INDEX location_search_tsvector_idx ON public.location_search USING gin (search_field_tsvector) TABLESPACE pg_default; Right now the output of pgstatginindex is this:
version pending_pages pending_tuples 2 214 9983 Lastly, here are some of the relevant config entries: autovacuum on autovacuum_analyze_scale_factor 0 autovacuum_analyze_threshold 50 autovacuum_freeze_max_age 400000000 autovacuum_max_workers 3 autovacuum_multixact_freeze_max_age 400000000 autovacuum_naptime 30s autovacuum_vacuum_cost_delay 20ms autovacuum_vacuum_cost_limit -1 autovacuum_vacuum_scale_factor 0 autovacuum_vacuum_threshold 50 cpu_index_tuple_cost 0 cpu_operator_cost 0 cpu_tuple_cost 0 cursor_tuple_fraction 0 effective_cache_size 125777784kB effective_io_concurrency 1 gin_fuzzy_search_limit 0 gin_pending_list_limit 4MB maintenance_work_mem 4027MB seq_page_cost 1 shared_buffers 62888888kB work_mem 200000kB SCOTT RANKIN Motus, LLC Follow us on LinkedIn |
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