Is the slow PostgreSQL query still in effect?

Is the slow PostgreSQL query still in effect?

The slow Postgres query is gone. The 0.1% unlucky few who would have been affected by the issue are happy too. Seeing the impact of the change using Datadog allowed us to instantly validate that altering that part of the query was the right thing to do.

Is it possible to drop an index in PostgreSQL?

There are two workarounds: Drop the index that misleads PostgreSQL. If that is possible, it is a simple solution. But usually one cannot do that, because the index is either used to enforce a unique constraint, or it is needed by other queries that benefit from it.

How does a sequential scan improve PostgreSQL query performance?

The PostgreSQL execution plan for this query was unexpected. Even though both tables have Indexes, PostgreSQL decided to do a Hash Join with a sequential scan on the large table. The sequential scan on a large table contributed to most of the query time.

When does Postgres create a unique index for a table?

from postgres documentation: PostgreSQL automatically creates a unique index when a unique constraint or primary key is defined for a table. postgresql.org/docs/9.4/static/indexes-unique.html – maggu May 26 ’18 at 2:36.

What does it mean when a query is running in PostgreSQL?

If a query (or set of queries) in question has the status of ‘active’, then it’s actually running. If the whole query isn’t available in pg_stat_activity, fetch it from the developers or the postgresql log and start exploring the query planner.

What does ” waiting ” mean in PostgreSQL 9.5?

(PostgreSQL 9.5 and before only has a boolean column called ‘waiting’, true if waiting, false if not. 1.1. Is the query waiting / blocked? If there is a specific query or queries that are “slow” or “hung”, check to see if they are waiting for another query to complete.

Is there a problem with the PostgreSQL database?

Whether it’s a panicked email, or an open ticket for “the database feels slow”, this common task can generally be followed with a few steps to check whether or not there is a problem with PostgreSQL, and what that problem may be. This is by no extent an exhaustive guide, nor do the steps need to be done in any specific order.

How to select top n rows in PostgreSQL?

Window functions provide the ability to perform calculations across sets of rows that are related to the current query row. One of the function is rank () using which, we can add a new column which contains the rank of the current row in each group. We generate a rank using a query as follows:

Is there a way to improve Postgres database performance?

It still has a very noticeable impact on Postgres performance. Remember that the query is quite simple. It’s a primary key lookup so there aren’t many obvious ways to fix it without dramatically re-architecting the database or the application. We turned to the community for help via the PGSQL-Performance mailing list.

How long does it take Postgres to respond to a query?

In 99.9% of accounts these queries would be zippy. In a few cases where the number of tags used to annotate metrics is large, these queries would take up to 20 seconds. That much time spent in a database meant that someone was waiting in front of their browser for the graph editor to respond.

How to do simple update in PostgreSQL database?

I am trying a simple UPDATE table SET column1 = 0 on a table with ~3 million rows on Postegres 8.4 but it is taking forever to finish. It has been running for more than 10 min. now in my last attempt.

Which is the equivalent of now in PostgreSQL?

now() is a traditional PostgreSQL equivalent to transaction_timestamp(). All the date/time data types also accept the special literal value now to specify the current date and time (again, interpreted as the transaction start time). Thus, the following three all return the same result:

How to disable run time statistics in PostgreSQL?

Specify pl to track only procedural-language functions, all to also track SQL and C language functions. The default is none , which disables function statistics tracking. Only superusers can change this setting.