Slow Query Help - Mailing list pgsql-performance
From | Will Platnick |
---|---|
Subject | Slow Query Help |
Date | |
Msg-id | ED51F03F1D2C469EB2F7FF91C677AD4F@gmail.com Whole thread Raw |
Responses |
Re: Slow Query Help
Re: Slow Query Help |
List | pgsql-performance |
We upgraded from PG 9.1 to 9.2. Since the upgrade, the # of active queries has raised significantly, especially during our peak time where lots of users are logging in. According to New Relic, this query is now taking up the most amount of time during peak activity and my pg_stat_activity and slow log sampling agrees. We have 3 DB servers referenced here, production running 9.2.2, semi-idle (idle except for replication when I ran the test) running 9.2.2, and 9.1.3 completely idle with an old dump restored.
HW: All servers have the same amount of RAM and CPU and all our indexes fit in RAM. HD's differ, but they're all SSD and since the explain analyze's are all indexes, I'm going to assume it doesn't mean that much in the context.
Configuration across all three servers is the same.
Table was auto vacuumed today.
Idle DB running 9.1.3
http://explain.depesz.com/s/7DZ
Semi-Idle DB running 9.2.2 (transactions ran previously and replication happening, but no active traffic when query was ran)
http://explain.depesz.com/s/fEE
Production DB running 9.2.2 (Incredibly Active)
http://explain.depesz.com/s/qVW
Table "public.users"
Column | Type | Modifiers
-------------------+--------------------------+----------------------------------------------------
id | integer | not null default nextval('users_id_seq'::regclass)
created_dt | timestamp with time zone | default now()
last_login_dt | timestamp with time zone | default now()
email | character varying | not null
verified | boolean | default false
first_name | character varying |
last_name | character varying |
username | character varying(50) | not null
location | character varying |
im_type | character varying |
im_username | character varying |
website | character varying |
phone_mobile | character varying(30) |
postal_code | character varying(10) |
language_tag | character varying(7) | default 'en'::character varying
settings | text | default ''::text
country | character(2) | default ''::bpchar
timezone | character varying(50) | not null default 'UTC'::character varying
verify_hash | character varying |
bio | character varying(160) |
twitter | character varying |
facebook | character varying |
search_updated_dt | timestamp with time zone | not null default now()
source | character varying |
auto_verified | boolean |
password | character(60) |
google | character varying |
gender | smallint | not null default 0
birthdate | date |
weibo | character varying |
Indexes:
"users_pkey" PRIMARY KEY, btree (id)
"u_auth_email_index" UNIQUE, btree (lower(email::text))
"u_auth_uname_index" UNIQUE, btree (lower(username::text))
"u_auth_verify_hash_idx" UNIQUE, btree (verify_hash)
"users_search_updated_dt_idx" btree (search_updated_dt DESC)
pgsql-performance by date: