Questions tagged [vacuum]

The vacuum command in postgres releases unused space. Be sure to also include the [postgres] tag, and version tag such as [postgresql-9.6]. Include an operating system tag,

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PostgreSQL did not released space "UPDATE set column = null", vacuum did not worked too

I have a huge table that I cannot delete the rows, only update the columns that are storing huge base64 data, that I should update to null to try to release space. So I programmed a script that are ...
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Does UPDATE write a new row version for unchanged, TOASTed values?

I am working with a PostgreSQL table with a large TEXT field, which is theoretically updated on a regular basis. I have thought about storing the data directly in the filesystem, but with TOAST, the ...
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Ringstorage: DELETE based on table usage

I am very new to LARGE DATABASE related stuff and Postgres, We plan to have a Postgres db with a million of rows that can grow up to Terabytes because rows include binary data (images). We plan to ...
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What happens during auto vacuum / vacuum in PostgreSQL?

The official documentaion here seemed quite cryptic to me. https://www.postgresql.org/docs/13/routine-vacuuming.html#AUTOVACUUM Can someone offer an explanation of what happens under the hood during ...
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Production PostgreSQL Space Issue, Huge pg_largeobject, Newbie Thrown Off the Deep End! [closed]

Server: PG 9.4, Linux, poorly/defaultly setup, no care and feeding Databases: 6 user databases, all on pg_default CT database: ~435GB pg_largeobject in that DB table size: 427GB total size: 433GB ...
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Autovacuum on tables with high-volume updates

I have a database with two tables where every 5 minutes the entire content of those tables is updated (mainly just a single column). The biggest of the two tables has about 170K rows. The autovacuum ...
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Does cancelling a VACUUM SORT in Redshift make all the work done useless?

I've tried to run a VACUUM SORT on a massive table for several weekends now, starting them Friday night and praying that they finish by Monday morning, but every time have had to kill it, because it ...
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Reclaim space after a failed VACUUM FULL

I made small miscalculation and my VACUUM FULL ended up filling the disks of the instance. I managed to free enough space to restart postgres but I am afraid it won't be enough to run VACUUM FULL to ...
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Postgres slow query on nullable index

Postgres version: 12.7 Table definition: column_name, data_type, is_nullable "id", "integer", "NO" "data",...
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Preventing Transaction ID Wraparound with vacuum freeze

I recently got few DBs to maintain. I just come up about this "Preventing Transaction ID Wraparound Failures". I checked my DBs and got the numbers: I did vacuumdb -a -v on this DB, and ...
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Vacuum on large table sometimes takes very long

In a PostgreSQL 11 database server I have a large table (932 million rows, 2150GB, not partitioned) into which I insert about 2-3 million rows every night with a batch job. The table was created with ...
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vacuum freeze PostgreSQL

Sometimes I find it difficult to understand postgreSQL documentation. Now, VACCUM section (https://www.postgresql.org/docs/10/sql-vacuum.html) says this phrase "Aggressive freezing is always ...
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Postgres LISTEN transaction prevents auto-vacuum from clearing dead tuples

At work, we have a database table we use for queued jobs, so it sees a lot of throughput. One issue we've run into is that after a weekend without any code changes, the indexes on this table fill with ...
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Are reportedly "bloated" index sizes a problem?

I create a table with 1 million records, then I delete those records. (Common with some sort of processing list.) CREATE TABLE example (id int PRIMARY KEY); INSERT INTO example SELECT generate_series(...
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Index maintenance on pg_catalog tables in AWS RDS

I have had some bad historical usage on my Aurora PostgreSQL instance. Namely, connections that create a lot of temporary objects and some very long running transactions (which limits autovacuum). Now ...
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Is vacuuming a PostgreSQL materialized view necessary?

I understand it makes sense to analyze a Materialized View (MV), but since MVs are not updateable, does that imply that we need not ever vacuum a MV?
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postgresql vacuum analyze on restored snapshot

Frequently we restore a Postgres DB from a RDS snapshot to an entirely new RDS instance. We notice that queries on certain tables perform really slowly but improve by a huge magnitude after running ...
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Do I need to Vacuum DB after massive insert?

I use Postgres 12.7 I did massive insert using CopyManager. Input: 320GB of tab separated data Sample row is: 2021-03-16T07:14:41.121000 588467 1900000 0 0 0 0 S 0 LITTLE_CHAR -- ...
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Disk space requirement for REINDEX in Postgresql

There is a server with postres 13 running out of disk space. It contains a table metrics that occupies 90% of the entire database. I have deleted old records in this table. Due to this table is used ...
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Postgres database insert become slow after 10 days, and then it needs a full vacuum

We have a postgres database which is almost 15GB's in size after vacuum. With a dedicated hardware i,e 32GB of ram with 12 Cores. The data automatically gets inserted around 300k inserts per day, and ...
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Questions about Free Space Map of PostgreSQL

Let's create a temporary table (I choose temporary table because autovacuum don't run for this kind of tables): CREATE TEMP TABLE test ( id int PRIMARY KEY GENERATED ALWAYS AS IDENTITY, value int )...
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UPDATE on big table in PostgreSQL randomly takes too long

I'm trying to figure out why an UPDATE statement takes too long (>30 sec). This is random, i.e. in most cases it finishes in under 100msec. However, sometimes (randomly) it takes > 30sec to ...
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Keeping postgres connection behind load balancer alive during long-running query (vacuum)

Background: I have a postgres instance behind a load balancer (AWS Classic Load Balancer). I want to access the database from another cluster through the load balancer and run queries. I cannot change ...
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Tracking (un)successful autovacuums in postgres

I am trying to help a team of junior, senior, principal and chief (mostly JEE) developers to be more data-centric and data-aware. In some cases we look into the data-processing costs, complexity of ...
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Postgres strategy for UPDATE SET x = NULL

It is not clear the strategy Postgres takes when columns are set to NULL: UPDATE tbl SET col1 = NULL, col2 = NULL WHERE created < current_date - INTERVAL '1 year'; Documentation https://www....
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AWS Aurora for PostgreSQL strange vacuum cost parameters

Today, I found out that in AWS Aurora for PostgreSQL 11 the default cluster parameter vacuum_cost_page_miss = 0 whereas vacuum_cost_page_hit = 1. I'd love to understand the logic behind pricing a page ...
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VACUUM ANALYSE not reducing index bloat, only VACUUM FULL

We are experiencing many slowdowns due to index bloat. On trying to optimize the index, recreating it seems to generate a much smaller index: ...
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How to predict how much space a VACUUM FULL would reclaim?

Is there a way to determine in advance how much disk space a VACUUM FULL on a particular table would return to the OS? Therefore you can decide whether it's worth the cost in doing so. Bonus if there'...
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nulls on pg_stat_get_progress_info('VACUUM') columns on pg_exporter role

I'm trying to export the results of a query select * from pg_stat_progress_vacuum;. The problem is that the only column values I can see from the created user are: pid datid datname Other columns ...
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PostgreSQL - 1 billion rows table cannot get vacuumed despite no errors

I have a statistics table that should be processed in a scheduled task to remove rows and count them into a separate, smaller table. Unfortunately the cron task failed for some period of time and the ...
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In PostgreSQL, if crashes during VACUUM, will it recover from a checkpoint that is before the frozen transaction ID of VACUUM?

When VACUUM starts, it will calculate a frozen transaction ID and freeze all tuples older than it. Will this frozen TXID be younger than the latest checkpoint? If this is the case, then when the ...
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2 votes
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Does dumping/restoring do the same as "vacuum full"?

I have a large database running with PostgreSQL v11, and the disk space is very limited, so I have to VACUUM (FULL) the database frequently (e.g. every day). But vacuuming is a very time-consuming ...
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Why is autovacuum running during a VACUUM FREEZE on the whole database?

I have a 14.7 TB Postgres(9.1) database that has to endure heavy writes for prolonged periods of time. I know that I need to closely manage my transaction ids to prevent db lockup. Recently I noticed ...
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Why isn't autovaccum running/completing?

My PostgreSQL instance (AWS Aurora) isn't autovacuuming. Or it is, but it is somehow being interrupted or stopped. I'm not canceling any autovacuum queries (though I suppose AWS itself could be). The ...
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Table recent performance degradation

So on my current project we have an ETL process that on its final stage ends up writing about 35 million of records on table on a PostgreSQL database (PostGIS actually). The version we are currently ...
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Stored Procedure for Vacuum in PostgreSQL

I want to create a stored procedure to trigger vacuum, I know there are many ways to automate vacuum, but I would like to use the stored procedure (Postgresql 9.6). The problem Im facing is, I can't ...
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Why is VACUUM FULL necessary here?

Queries are running very slowly on a table with 80k rows. SELECT count(*) FROM task takes <100ms. SELECT type, count(*) FROM task GROUP BY type takes 30,000ms. Basically, any query that is not ...
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How to have PostgreSQL running forever with constant insert and delete per day

Question: Lots of rows are getting inserted every second. Batch deletion is performed when the disk is close to full. This causes two problems: It is impossible to examine actually how much space in ...
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1 vote
1 answer
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Long running VACUUM VERBSE in Postgres 9.5 - how much time remaining?

I am vacuuming a very large (718GB) table containing a lot of dead tuples and 4 indexes. VACUUM ANALYSE VERBOSE bigtable; This vacuum has been running for over 11 hours (!) now and I am trying to ...
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How to maintain visibility of all new transactions in append-only PostgreSQL DB without scanning the whole table

Situation PostgreSQL v11 I have a database with a dozen tables. No rows are ever DELETEd or UPDATEd. A bulk of data is INSERTed to all the tables in a 'few' (up to 1,000) transactions every day. ...
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Why is VACUUM FULL locking ALL databases on the cluster?

From everything I have read about VACUUM FULL, I would expect it to lock the database I'm running it on, but it renders every database in the cluster inaccessible. Is there perhaps something we might ...
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2 votes
1 answer
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How much disk space was made available to Postgres by VACUUM that is not available to the OS?

VACUUM does not return disk space to the OS, instead it marks dead rows to be reused for future writes. My server has almost ran out of disk space, afterwards I ran DELETE FROM big_table to clear ...
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3 votes
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How do I fix multixact wraparound after it has already occurred?

I have a database which has a single table for which MultiXact wraparound has already occurred. Neither manual vacuums nor automatic vacuums are able to fix this condition. Manual vacuums fail almost ...
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Postgres 9.4.5 small table grows into huge size - periodic VACUUM FULL needed

We are running a PostgreSQL database on Windows Server. The database version is 9.4.5 (it's been running stable for a long time now so we aren't updating it). Some of our tables have millions of rows,...
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Postgres: Reclaiming Space

I have a server with 150GB of diskspace. Today I uploaded a dataset of 30GB. I cancelled the import due to internet dying, then noticed there was 29GB of space missing in the database (meaning the CSV ...
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Postgres VACUUM VERBOSE information

I am using Postgres with psycopg2 and sometimes when I run VACUUM VERBOSE table_name; it gives me a line giving the oldest xmin and sometimes it does not. Is there a way to make sure that it always ...
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Does a Postgres VACUUM free up space for any database object?

If I do a VACUUM on a Postgres table (without the FULL option) I know that it should make any free-space available to the database, but not the operating system. Should it make the freespace ...
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3 votes
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uncommitted xmin during vacuum, what to do?

Running vacuum on two specific tables in my postgresql 10 database results in the following error: VACUUM (FULL|ANALYZE|FREEZE|) table; ERROR: uncommitted xmin 359569171 from before xid cutoff ...
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Postgres VACUUM taking forever

I have an specific table that is taking forever o VACUUM. There are no locks in the DB and even letting it overnight the VACUUM didn't finish. According to the statistics (ANALYZE works fine) the ...
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Is it necessary to ANALYZE a table after an index has been created?

In my transaction, I am creating a temporary table: create temporary table x on commit drop as select ... I also add an index on that table: create index on x(some_column); Is it now necessary to ...
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