Questions tagged [postgresql]

All versions of PostgreSQL. Add an additional version-specific tag like [postgresql-13] if that context is relevant.

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pg_upgrade fails with an unspecified error

I’m running Postgres 9.1’s pg_ugrade to migrate from 9.0 to 9.1 on Windows x64. After editing the permissions to allow full trust, running the tool as the postgres user, and working around a bug ...
1 vote
1 answer
1k views

slow index scan on postgresql 9.1

I have a view which is amazingly slow :) It joins two tables only, having a few simple WHERE conditions and one in a form of a subquery (see SubPlan1 below). The simplest condition is checked as an ...
2 votes
1 answer
5k views

pg_restore: [archiver] unsupported version (1.11) in file header postgresql

My server is working on Ubuntu with PostgreSQL 8.4 and the development machine I'm using has Debian Lenny with PostgreSQL 8.3. My machine can't be upgraded to PostgreSQL 8.4 and I need to restore a ...
3 votes
4 answers
6k views

migrating tables from Postgres to SQL Server 2008

(I fear what I wish to accomplish shall not be easy, but a lot of my googling around about it yielded rather dated results, so here it goes...) I have a Postgres 8.4.x database with over 100 tables. ...
0 votes
1 answer
365 views

Update Postgres on server that already has version included with system

Mac OS X (Lion) Server includes Postgres (9.0.5) that it uses for some system utilities (Wiki server, caldav, etc.). I'm about to start using this server for some Rails applications and am wondering ...
3 votes
2 answers
1k views

pg_relation_size does not show any difference after VACUUM ANALYZE

I wrote a script to backup a postgresql using COPY and then delete those records. I have used pg_relation_size before and after delete. pg_relation_size DELETE VACUUM ANALYZE pg_relation_size But ...
4 votes
2 answers
3k views

psql won't list databases

I have a situation that I'm scratching my head over, but I'm new to postgresql, so I may be overlooking something obvious. I set up a testbed server and set access in pg_hba.conf: local all ...
2 votes
2 answers
2k views

Request suggestion for a database between MySQL and Postgresql

We maintain a list of all the SAN Switch Ports that are either free or allocated to hosts. Currently, we enter the information on the company portal. But we need to move if off to a database because ...
0 votes
1 answer
135 views

What DML commands can be allowed / limited on a reporting server?

I have a largish database (PostgreSQL 9.1) which I'm preparing to replicate using streaming replication. The 2nd server will be used for reporting and backup purposes. When building reports, it's ...
3 votes
1 answer
385 views

Postgres synchronized backup - what's with the archive?

I am setting up a Postgres 9.1 master and a hot standby-server. I read the documentation but I'm not quite sure yet what I should do with my WAL files. Every commit is done on both servers before ...
2 votes
1 answer
616 views

Working of window functions and idea window size for window function

I am not able to understand the concept of window functions. How exactly they work and what are the pros and cons of such technique? I have read that using limit and offset is slow but its still used....
1 vote
2 answers
2k views

Backup of Postgres database

I want to create a backup of my database in Postgres. I'm using pgAdmin. on my database I have clicked right button of mouse after that I've selected the "Create a backup of database" After that I'...
3 votes
1 answer
6k views

Disable automatic login in pgAdmin

I have enabled automatic login in pgAdmin and would like to disable it to make it possible to connect to the servers using different roles. How do I do this?
4 votes
2 answers
9k views

Reindexing a large database

I have a very large database (millions of rows) which has been indexed. I receive a diff of rows from another source that I need to update in my database. The problem I am facing is that is it ...
2 votes
1 answer
244 views

postgresql - transaction log - versioning?

Is it possible to "version" your database so that any change can be reviewed or roll backed? Obviously backups are important but being able to go back to any previous state of the database (at least ...
8 votes
1 answer
595 views

Upgrade postgres without messing with ports?

The standard procedure for upgrading Postgres appears to require that I temporarily run both the old and the new version. This means that I have to change the port of the old version. This seems ...
2 votes
2 answers
2k views

Attempting to avoid SORT in query planner

I have a query that is used VERY frequently in my application. Without modifying the query itself, I'm trying to optimize it by toying with different indexing schemes. Here's the query (basically): ...
4 votes
1 answer
6k views

PostgreSQL Scheduled Database Backup

For scheduling a daily back up on a postgres database we execute the following command: 0 2 * * * /usr/local/pgsql/bin/pg_dump -Fp -b -U database_name \ > $HOME/db_backups/database_name-`...
2 votes
1 answer
3k views

How to import the data of postgres 8.x to postgres 9.x

My OS is windows 7 x64. I was use postgres 8.4, and all databases are in postgres/8.4/data. Yesterday, I reinstalled my os system, but I found I can't install postgres 8.4 anymore (there is always an ...
6 votes
2 answers
4k views

Is Tablespace something like Logical Volume?

I'm confused about tablespaces in PostgreSQL. Is it something like LVM? I mean when disk is getting full, can we add another disk, format and then CREATE TABLESPACE tblspace LOCATION /media/disk2/data?...
2 votes
1 answer
4k views

Triggers not being run on a partitioned table

I'm using PostgreSQL. I have a table that I have partitioned into three sub-tables - and as far as I can tell, this all works correctly. Rows are correctly inserted into the appropriate partition and ...
2 votes
1 answer
571 views

Query takes hours

Up until now all queries in my PostgreSQL application were fast. During the last days, sometimes a query takes several hours. Index are healthy, because after dump, restore, vacuum -z, it is still the ...
1 vote
1 answer
622 views

Impact of changing schema name

I have a server with two databases. Each database has a different schema name despite the fact that DB2 is a subset of DB1 (DB2 has a subset of the tables in DB1). Not withstanding any code changes ...
5 votes
4 answers
3k views

Trouble setting up Postgres for the first time

I have some, albeit limited, experience with MySQL and MongoDB (both running fine on server) but having trouble with Postgres and find the documentation lacking for newbies, like myself. Postgres is ...
2 votes
1 answer
337 views

Streaming Replication on Two Postgres Systems?

There's two servers, a Primary Server and a Backup Server. Both have Postgres installed. The Primary Server has one database, and the Backup Server has two - one for a warm backup/standby of the ...
15 votes
1 answer
16k views

Postgresql performed a "fast shutdown" by itself. Why? How was it able to do that?

I've already googled and manual read as much as I could before posting this here. Version info: Postgres8.4 on Ubuntu10.x I have a personal laptop that I run a postgres server on, and a Java script ...
user avatar
1 vote
1 answer
407 views

Postgres shared_buffers and pooled processes

I have read several articles (including Postgres docs) that suggest setting the shared_buffer's config value to 25% of your total physical memory. Using my 4 GB memory as an example... If I ...
2 votes
1 answer
6k views

Postgres: trying to fix some unicode encoding issues

I've got a postgres 8.4 database with a few mangled characters in one of the columns on a table. For example, the word "don't" gets displayed within psql as: donâ\u0080\u0099t I want to be able to ...
7 votes
2 answers
3k views

Database for building a realtime analytics system

I want to build a system similar to Google Analytics (only used for internal use, less traffic and less feature), and mainly focus on Real time counting of unique URI visit/PV by different dimensions ...
5 votes
1 answer
5k views

WAL backups with pg_dump not possible?

I am hoping to move to WAL backup from pg_dump. But I am confused by this note in 4.3 documentation: Perform the backup, using any convenient file-system-backup tool such as tar or cpio. And in ...
0 votes
2 answers
275 views

New PostgreSQL 9.1 configuration doesn’t work

I changed the length of table names in PostgreSQL in the file pg_config_manual.h (in C:\Program Files\PostgreSQL\9.1\include) to 128. Then I reloaded the new configuration by selecting menu "Reload ...
7 votes
2 answers
4k views

Span single transaction over several sequential psql sessions

I am running PostgreSQL 8.4 database server and psql terminal front-end on Ubuntu 10.04 Lucid Lynx and would like to span a single transaction over several sequential psql sessions. When I connect to ...
0 votes
1 answer
230 views

How to improve restoring the PostgreSQL database?

I'd like to restore the PostgreSQL database from a dump. The below command works fine for me: CALL "%PGBIN%\pg_restore" -c -d NetCatalog %DUMPFILE% How can I add a few lines to my .bat file to ...
2 votes
1 answer
2k views

Postgres - how to randomize two columns in a table

I have a table of User data which I would like to disguise/anonymize. Two of the columns have location data (e.g. lat and long, both BigDecimals). I have anonymized all the names and other ...
1 vote
1 answer
411 views

Show all variations of 2 characters in postgres

How would I do this in postgres : Lets say I have an x and a y and I want to show all possible combinations : xx yy xy yx How can I make postgres do this for me ?
1 vote
1 answer
8k views

Postgres Administration roles

I need to work with a remote postgresql server. My application needs to perform the following actions: to be able to create/drop database (I only need to work with 1 specific database) to be able to ...
4 votes
1 answer
2k views

How can I escape XML field in XML-output query?

I have following request: SELECT XMLAGG(data) FROM (SELECT XMLELEMENT(name item, XMLFOREST( title, body as description, date_created as date, 'http://example.com/news'||id as link )) AS ...
2 votes
1 answer
3k views

Postgres Index scan forward vs backward = speed difference of 357X slower

PostgreSQL 9.1.2 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-51), 64-bit Dedicated DB server 4GB ram Shared_Buffers = 1 GB Effective_cache_size = 3GB Work_mem = ...
9 votes
2 answers
2k views

Pros and Cons of Checking if value exist for unique column or let db raise unique error on inserting

While writing a query other day a thought came to me and have stuck in my mind. What is preferable, first checking if a value for a unique column exists and then inserting or insert and let db raise ...
11 votes
2 answers
16k views

View Postgresql Memory Usage

I'm running Postgresql on a Ubuntu server and need to be able to monitor its memory usage. Currently I have scripts running in a one-minute cron job that monitor/log various statistics and need to ...
4 votes
1 answer
61 views

Want to add a "variable" to a table

I'm using PostgreSQL 8.4 and I have a table that is cleared out and refilled with new data every so often. I want to be able to store the date that the table was last filled, but I'm not sure where to ...
3 votes
2 answers
2k views

How does pgAdmin III build CREATE statements?

In PostgreSQL, there is no SHOW CREATE statement, known for example from MySQL. But when you use the pgAdmin III client program and go to object details, you see the corresponding CREATE statement. ...
0 votes
1 answer
611 views

Which file is PostgreSQL log file 0?

In my PostgreSQL logs, I find this message: LOG: invalid magic number 0000 in log file 0, segment 1, offset 16121856 Which file is log file 0? Here is my pg_xlog directory: -bash-4.1$ ll pg_xlog/ ...
1 vote
1 answer
6k views

restoring a table from sql file in postgresql through Windows Command prompt

Im trying to restore an sql file which contains the dumpf a table (with COPY commands) into a table into the database, it would be great if someone could share an example, as the pg_restore doesn't ...
1 vote
2 answers
10k views

Running postgresql in Mac Terminal

I have a production SQL dump file that I want to restore to my local psql db for debugging reasons. I can't access psql via the terminal though pgAdmin3 works just fine. Here is the error I'm getting:...
2 votes
2 answers
4k views

Update column by comparing date and string values together

I have problem in updating table. I need to update table by comparing date and name with another table. I have two tables: table 1 : dim_sesid name(varchar) role ...
2 votes
1 answer
646 views

Rewriting a query

I have a database with the following structure (star schema): facttable: pros integer mena integer me integer vahet double precision slutttp timestamp without time zone Structure of each ...
17 votes
3 answers
5k views

Does PostgreSQL 9.1 Streaming Replication catch up after a lag without WAL archiving?

Context: Let's say that, while using Streaming Replication/Hot Standby on a Postgres 9.1 cluster, a standby node goes down. It stays down for an day, during which time a lot of DML occurs on the ...
11 votes
2 answers
8k views

Can PostgreSQL create a case sensitive database?

I'm porting some code from some version of Sybase to PostgreSQL. This is a C application that uses the Sybase client library. My approach is to write a translation layer that translates calls to ...
2 votes
1 answer
671 views

Why is a duplicate record inserted when it should not be?

Why does this command insert into "deliveryLog" select * from temp_dellog where "deliveryID" < 15620652 give this output? ********** Error ********** ERROR: duplicate key value violates unique ...