PostgreSQL is an enterprise class, open-source, object-relational database management system (ORDBMS) available for all major platforms including Linux, UNIX, Windows and OS X. Please mention your exact PostgreSQL version when asking questions.

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“Truncate” or “Delete/Vacuum Full” for deleting some of the table rows

I have a db which has 223 tables and I have to delete some of the records from 10 of them, each has apprx. 1.5million records. Those tables are storing the temperatures every 7seconds. We have decided ...
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1answer
489 views

No way to set maximum retrieved rows in pgadmin query tool

I'm using version 1.16.1, and I can't find a "max(imum) rows" param to tweak. Any help would be appreciated.
3
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1answer
233 views

How un-clustered is a CLUSTER USING table in PostgreSQL

I have some tables which benefit greatly from CLUSTER ON/CLUSTER USING in Postgres SQL: # CLUSTER table USING index_name; # ANALYZE VERBOSE table; # CLUSTER VERBOSE; A maintenance task periodically ...
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3answers
1k views

PostgreSQL group roles

This is not a "group by" question. I am struggling with permissions in postgres because I apparently don't understand how group roles work. Searching for this on SO has proven difficult because I get ...
4
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1answer
111 views

How to get the information of the optimizer of PostgreSQL?

I am curious about the information like total optimization time the time spent on each stage of optimization the number of alternative plans and the cost of each alternative plan.
2
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1answer
61 views

psql coloured prompt misbehaving

In theory, there is a possibility to use coloured prompts in psql. I decided (not the first time :) that I need them, so I thought I would give them a try. So I have in my .psqlrc the following: ...
3
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2answers
4k views

Configuring PostgreSQL for read performance

Our system write a lots of data (kind of Big Data system). The write performance is good enough for our needs but the read performance is really too slow. The primary key (constraint) structure is ...
5
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2answers
199 views

Inconsistency in repeatable read

http://www.postgresql.org/docs/9.2/static/transaction-iso.html The Repeatable Read mode provides a rigorous guarantee that each transaction sees a completely stable view of the database. However, ...
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0answers
919 views

Can't set up witness in Repmgr 2.0

I am trying to setup repmgr using the autofailover quick setup tutorial provided on Github Link But I am kind of stuck on the witness section, when trying to create the witness with repmgr -d repmgr ...
0
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1answer
266 views

String replace using concatenated strings from various columns

I'd like to remove a substring in a column via update statement. The substring to replace consists of multiple strings from other different columns but in strict order. The specification says: ...
4
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1answer
3k views

How to simplify a nested SELECT with PostgreSQL arrays?

I'm trying to speed up and simplify a SQL query against an imported OpenStreetMap database (OSM). The database is stored in a PostgreSQL 9.2.4 server. This OSM import features two particular tables, ...
0
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1answer
257 views

Pattern matching and substring replacement in PostgreSQL [closed]

I would like to do pattern matching and substring replacement in PostgreSQL with a "select-case-when-then-update-query". Example: tableA field1 |field2 | field3 ...
0
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1answer
445 views

How to install and configure Postgres-XC in windows?

Can anybody suggest me any resources of the complete installation procedure of postgres-XC in windows. I've installed postgresql-9.2 in my windows and can use it. Now I need to know the installation ...
3
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0answers
139 views

What happen when Postgresql tablespace is null?

I'm facing a DWH on postgresql with no DBA (I'm not one) so I turn to you with hope to figure this issue/s. Long story short, when I check the disk usage per tablespace, I get different distribution ...
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1answer
434 views

Use select query in stored procedure

I have some questions about stored procedures. Using select query inside the stored procedure is efficent or using select query in front end. Which is take less time and give the result is fast or if ...
0
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1answer
148 views

PostgreSQL created a PostgreSQL user on mac. Is this necessary?

I just installed PostgreSQL on a Mac (Mountain Lion) today. The installer created a mac user PostgreSQL on my machine. After installation, the user still exists. My question is that why postgreSQL ...
16
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1answer
4k views

How can I benchmark a PostgreSQL query?

I want to benchmark a query containing an user-defined function I have written for PostgreSQL. Are there any standard ways to run such a benchmark? I know that timing can be turned on with \timing ...
1
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1answer
535 views

How to monitor or do vacuum without stop all?

I have postgres9.1 I try to run full vacuum on a specific table , but it run for more than 5 hours. I stop all process against this table and i cannot have the process down any longer. Is there a ...
4
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1answer
192 views

How to view the full, flattened query underlying a Postgresql view?

If I have a view on a view on a view (etc.), is there a way to show the full query that this expands/flattens to?
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1answer
528 views

createdb command error : could not connect to database [closed]

I am using the following command for creating database in postgresql. createdb -D pg_default -E UTF8 -h localhost -p 5432 -U pramil -W pramil mydb but this command results prompt for password.When ...
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2answers
1k views

Seeting up a PostgreSQL database on another hard drive than my system one on OS X?

I am on OS X 10.8.3, I've install PostgreSQL from macports, but I've realized that I have not enough space on my system drive for the DB I am about to populate with data. Is there a way to create new ...
2
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1answer
469 views

Encryption in PostgreSQL

Does PostgreSQL support data encryption features at transactional and the table level of database? If yes, how? Oracle provides this via database and network encryption. Oracle provides encryption at ...
0
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1answer
143 views

Syntax error when trying to import database from two PostgreSQL databases

Following on from this prior question, I'm trying to export a database from one server and put it on another using phpPgAdmin. My process is like this: select the database in server 1 and hit the ...
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0answers
2k views

createdb: could not connect to database postgres: FATAL: could not write init file [closed]

RedHat Enterprise Server 3.0 32 Bits psql (PostgreSQL) 8.2.3 user: postgres server is running: /soft/postgres/8.2.3/bin/pg_ctl start pg_ctl: another server may be running; trying to start server ...
3
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2answers
436 views

General tool to load dump files [closed]

I am a big fan of Postgres both for its price but also for its features. I am going to have to need to upload into it both Oracle dump and SQL Server files. I will try to ask and beg for plain .csv ...
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1answer
180 views

Restrict access for Windows administrator in PostgreSQL

Is there a way to protect PostgreSQL from user with Windows administrator rights? Like this question but for Postgres.
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2answers
190 views

Group Database Entries by time difference

I have a large postgreSQL database with log data. All this data has timestamps and I want to group consecutive rows where the difference between the timestamps is less then 1500 miliseconds for ...
0
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1answer
121 views

Writing with multiple psql processes to database seems to damage data

I have a couple terabytes of CSV data that I am trying to import into a PostgreSQL 8.4 database (on a RedHat 6.2 server), whose data directory is initialized on a multipath hardware RAID. There are ...
2
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1answer
920 views

Is replication from SQL Server 2008 to PostgreSql possible?

Is it possible ? Sql Server as publisher(master) and PostgreSql as slave(subscriber) ? Any type of replication really.
0
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1answer
1k views

pg_dump from 9.2 to 8.4 [closed]

I'm trying to restore a db dump from PostgreSQL 9.2 to PostgrSQL 8.4 (from separate machines, both are running Windows 7). I followed the instructions in this answer: Use pg_restore to restore from ...
3
votes
1answer
645 views

Is it safe to call pg_ctl reload while doing heavy writes?

I am running Postgres 8.4, and I would like to change the authentication method for a user. It's my understanding that I have to do this in pg_hba.conf, and then reload the configuration files with ...
2
votes
1answer
4k views

Select first row (grouping) + add aggregate function

First have a look at this question on StackOverflow. I'm looking to accomplish the same task, except I also need to add an aggregate function (PostGIS's ST_Union) to my query. How can I combine the ...
0
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2answers
23k views

Can't connect to the postgres server ls: /tmp/.s.PGSQL.5432: No such file or directory

*Update*I included an update at the bottom of this post with details from the logs explaining the problem that I haven't been able to fix. Following along with this Railscast ...
2
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2answers
1k views

Changing PostgreSQL port using command line

My PostgreSQL default port is 5432, I want to change default port by using command line (in Windows 7). I saw this solution before: http://stackoverflow.com/questions/187438/want-to-change-pgsql-port ...
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4answers
2k views

Daily and Differential Backups [closed]

Is there a program with which I can create daily MySQL, PostgreSQL and MariaDB backups with these requirements: The first time, make a full backup. The second time, only the changes since the last ...
1
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1answer
1k views

Use cases for hstore vs json datatypes in postgresql [closed]

In Postgresql, the hstore and json datatypes seem to have very similar use cases. When would you choose to use one vs. the other? Initial thoughts: You can nest with json; you can't with hstore ...
2
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4answers
2k views

Database design - People and Organisations

Databases are not my primary skill and I am finding I need some assistance please. The software we are building has "Customers". The Customer could either be a Person or an Organisation. I really ...
5
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1answer
285 views

force PostgreSQL into recovery mode

I have a somewhat strange question. Is there a way to manually force PostgreSQL into recovery mode? I've not been able to find aything in the documentation. I've been working with a script ...
3
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1answer
106 views

Why do psql queries take longer when inserting many rows. Why is it non linear

So if I insert a single row into a postgres database it takes 18 ms. If I do this in a loop like this: INSERT INTO contacts (numbers) SELECT distinct array[ (random() * 99999999)::integer, ...
1
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1answer
602 views

Foreign Key to Multicolumn Primary Key?

I have three connected table in my design. Basic logic is when a category deleted, also delete records in category_product table which has deleted category's id in its cat_id column. But when I tried ...
0
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1answer
223 views

Postgres - Schema information within Trigger?

Background : (Multi-tenant design;separate schema per customer, all table structures identical;Data-warehouse / non-OLTP system here; Postgres 9.2.x). Reviewing patterns for the following problem: I ...
0
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1answer
181 views

OK to put temp tablespace on volatile storage or to omit it from backups? (Postgresql)

I would intuit that it's fine, but I just want to make sure there are no gotchas from a recovery point of view: If I were to lose my temp tablespace upon system crash, would this prevent proper crash ...
1
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0answers
99 views

PostgreSQL datasource URL?

My first attempt to use PostgreSQL: I have the elephant icon on the top right: running on port 5432. I want to use LibreOffice as an interface: Connect to an existing database: PostgreSQL ...
1
vote
1answer
1k views

PostgreSQL stored function that returns arbitrary resultset

I would like to write a PostgreSQL stored function that essentially behaves like the stored procedures I know and love from MSSQL and MySQL where I can just wrap a query that takes no parameters and ...
2
votes
2answers
843 views

Read Committed Isolation Level

Quote from docs: Read Committed is the default isolation level in PostgreSQL. When a transaction uses this isolation level, a SELECT query (without a FOR UPDATE/SHARE clause) sees only data ...
1
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1answer
10k views

Performance difference between MySQL and PostgreSQL for the same schema/queries [closed]

I'm a newbie DBA, and I have experience in Microsoft SQL Server but I want to jump to FLOSS. I'm starting a company, and we develop an app (PHP) with a Postgres backend, and we did some tests ...
1
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1answer
374 views

Table for optional parent/child relationship

Assuming we have the following table: Item, Parent, Child and Parent is the parent of child. The item can either belong to a parent or child and not both. I have other tables that are similar to ...
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0answers
337 views

PostgreSQL: Slave doesn't replicate the Master's data

I'm using PostgreSQL 9.2.3 on both computers, both of which run Win2008R2. I've setup streaming replication by following this guide: ...
4
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2answers
457 views

Is it ever a good idea to denormalize for integrity?

I'm using Postgres 9.2 to develop a quiz app, in which I present the user with a series of problems and record their answers. These problems can take a variety of forms - they might be multiple ...
0
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1answer
43 views

Storing no of players the last seven days in an online game

I want to plot the number of players, in the last seven days, of an MMORPG which haves 50~ servers. The system fetches the number of players in each server every 15 minutes and I'm not really sure how ...