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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Trying to restore a corrupt Postgresql database, with corrupt data folder. Able to start postgres but the tables are empty?

Postgres 9.3 on Ubuntu 12.04 We had some disk corruption on our server, and after doing a fsck the database would not start. To get us back into production, I copied the postgres data folder, blew ...
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1answer
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Can I provide a default for a left outer join?

Suppose I have tables a (with column a1) and b (with columns b1 and b2) and I perform a left outer join SELECT * FROM a LEFT OUTER JOIN b ON a.a1 = b.b1 Then b1 and b2 will be NULL where a value of ...
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2answers
259 views

Postgres 9.2 - Create View Different Column Names

I want to create a view of a table with a column renamed. I do not want to effect the source table, just the view. I need to rename the column addr:housename to addr_housename. We have a 3rd party ...
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1answer
155 views

Appending imported data in Postgres

This is what I typically use to import csv data into my postgres database.. \COPY master_list FROM '/root/raw/file.txt' DELIMITER ',' CSV; Usually it's into a blank table, but in this case, I need ...
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1answer
460 views

Sync offline PostgreSQL server

I am new to PostgreSQL. I am looking for a solution wherein 2 mirror images of a database sit on a local and remote server. All the work is done on the local server and at periodically synced with the ...
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1answer
315 views

Taking hot backup of slave node in postgres (master-slave config with repmgr)

I have a postgresql setup with master-slave configuration using repmgr. I'm struggling with taking a consistent snapshot backup (pg_start_backup) of the slave node, this is due the fact that the slave ...
3
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1answer
212 views

PostgreSQL: When should I use fillfactor < 100 for tables on SSD?

PostgreSQL documentation says that choosing smaller fillfactor lets table reserve space for future updates on the same page and "This gives UPDATE a chance to place the updated copy of a row on ...
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3answers
122 views

How to map similar camelcased, pascalcased, underscored, lowerscored words to the same id?

I'm working on PostgreSQL and I have a table like this called words_table: I need all equivalent words (like software_design and software-design) to have its map value = to its word's equivalent ...
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1answer
43 views

General purpose view for last value in a group

I am trying to create a view to show the last value in the group. Looking for a more general purpose query. CREATE TABLE a ( id INTEGER, seq INTEGER, val VARCHAR2(16), PRIMARY ...
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3answers
5k views

Select query to retrieve values even if are null

I need some help in a query. Need to retrieve data from 1 table, even if one of the field has null value. Here's an example: Select name, SUM(credit) as credit From expenses Where name like ...
3
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1answer
435 views

Determine the currently executing statement in a long running PL/pgSQL stored procedure

I have a long running PL/pgSQL stored procedure in PostgreSQL. How can I determine the currently executing statement in it?
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1answer
380 views

Importing data from MS Access database to an existing Postgres database

I'm developing a Django based website with a Postgres DB. The problem I'm having is importing the data from an Access DB into it. To be specific, I'm not trying to translate/import the schema from ...
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1answer
3k views

How to reclaim disk space on PostgreSQL?

I have local installation of 9.1 database with few tables which had cca. 300 mio records and the database grew to about 20 GB. Afterwards I issued delete from command to delete all records from it (I ...
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1answer
1k views

PostgreSQL user permissions

I have a PostgreSQL 9.3 database with the PostGIS extension backing a web application and GeoServer. I have created three users. A read only user for accessing the data in the reference data schema. ...
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1answer
4k views

PostgreSQL High Availability/Scalability using HAProxy and PGBouncer

I have multiple PostgreSQL servers for a web application. Typically one master and multiple slaves in hot standby mode (asynchronous streaming replication). I use PGBouncer for connection pooling: ...
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3answers
84 views

Postgresql: Make Column Default a Query

Is there a way I can set up a column in PostGreSQL 9.2 such that the default value is a query? I am having to track down query statements from different sources that don't respect the "default" ...
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471 views

Postgres Backup on linux server [closed]

I am trying to take backup of postgres from InstallAnyWhere which is installer for linux and windows machine. I am calling pg_dump from Java process builder as command line below cmdLine: ...
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2answers
102 views

Does Postgres support stored column labels that can be queried?

I'm not a DBA but seem to recall that there was a SQL database that stored column labels (preferred column headings that can be printed on reports). Does Postgres support labels such as these?
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1answer
503 views

Fastest way to get current user's OID in Postgres?

I am thinking of storing the user's OID in the "owner" column of a table, so I don't have to do anything if they change their username. I understand one can use pg_has_role() with OIDs, so that's ...
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3answers
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VACUUM FREEZE vs. VACUUM FULL

Can someone explain the difference between these types of VACUUM in PostgreSQL? I read the doc but it just says that FULL locks the tables and FREEZE "freezes" the tuples. I think that's the same. Am ...
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2answers
1k views

PostgreSQL - pgAdmin error creating a server

I have the latest versions of PostgreSQL and its GUI-frontend, pgAdmin, installed. When I try to register a new server a fatal error appears when pgAdmin tries to connect to the newly created server - ...
5
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1answer
337 views

Replace a materialized view in Postgres

I have a materialized view in Postgres 9.3 that I'd like to update with new columns. Other materialized views also depend upon this view, but the error message indicates that dropping a view isn't ...
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1answer
209 views

Problems using “Excel PostgreSQL Import, Export & Convert Software” [closed]

I want to export data from Postgresql, and I tried many ways then find the tutorial of Excel PostgreSQL Import, Export & Convert Software on Youtube. I installed the software, but I could not ...
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2answers
1k views

Migrate heroku database to Amazon RDS with minimum downtime

I have a heroku postgres database and want to migrate it to Amazon RDS to save cost. What's a way to do so with minimum downtime? Usually this involves replicating database in real time and then ...
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1answer
626 views

PostgreSQL FTS and Trigram-similarity Query Optimization

I have recently started working on PostgreSQL and I have around 12M rows to handle in which I want to apply Full Text Search. I don't have any prior experience in handling such databases. I have tried ...
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0answers
953 views

hstore vs redis performance wise (without durability) [closed]

How do PostgreSQL's Hstore and Redis compare performance-wise? This question was asked here, but I would like to compare with a PostgreSQL configuration without durability guarantee, i.e. with ...
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2answers
158 views

Vacuuming database termination for postgreSQL

I was doing database vacuuming to free up disk space for postgreSQL database. The corresponding table size was large and it was taking long time for vacuuming to get complete. But unfortunately ...
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1answer
342 views

How to copy the postgresql's xlog files safely

I mean how to safely copy xlog files when postgresql is running? Any reply will be appreciated.
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1answer
280 views

Asynchronous commit on Postgres over iSCSI with BBU storage

It is my understanding that it's alright to turn synchronous_commit off if your server has a local, battery backed up storage controller. In my environment I am on a VM whose block storage is ...
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1answer
1k views

PostGIS “could not open extension control file” when creating extension

I've followed the instructions here to install PostGIS http://trac.osgeo.org/postgis/wiki/UsersWikiPostGIS21UbuntuPGSQL93Apt but when I went to create the extension I got the following error. I'm ...
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2answers
2k views

How to get all roles that a user is a member of (including inherited roles)?

Let's say I have two Postgresql database groups, "authors" and "editors", and two users, "maxwell" and "ernest". create role authors; create role editors; create user maxwell; create user ernest; ...
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0answers
894 views

Postgres Case statement not return else value in this query

I'm creating a SQL query with a some nested queries and I'm trying to use the CASE statement but it is behaving weirdly. I've been at it for at least 6 hours without any luck... This is my query at ...
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1answer
548 views

Even after permissions are updated, I still get the error permission denied for relation users

I'm getting the error ERROR: permission denied for relation users and have tried to update privileges using both grant all privileges on all tables in schema ops to my_user GRANT ALL PRIVILEGES ON ...
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2answers
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What is the search_path for a given database and user?

I can see the current search_path with: show search_path ; And I can set the search_path for the current session with: set search_path = "$user", public, postgis; As well, I can permanently set ...
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1answer
292 views

Automatically generate ALTER TABLE to syncronize schema on PostgreSQL

i Have 2 different database schema in PostgreSQL sql file from pg_dump, is there automated way to generate alter table commands so it would be in sync, without inspecting one by one? this is the ...
5
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4answers
8k views

Select COUNT of days between two dates except weekends

I am trying to get the number of days between two different dates, except the weekends. I don't know how to achieve this result.
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1answer
570 views

Postgres - Optimizing an view dependent on an aggregate function?

I have a table of about 15 million records. Whenever information about a specific charge_id is changed, a new row is added with the current timestamp and the changes. This results in multiple rows ...
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2answers
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What database should I use to create a webmail service like gmail? [closed]

I planned to use python for my frontend with django framework. But for backend, I have no idea which database I should use. Since it involves plenty of reads and writes can someone point me in the ...
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1answer
2k views

PostgreSQL list of integers separated by comma or integer array for performance?

As per subject, I have a field which is varchar in which i store some numbers separated by commas. The list grows and shrinks based on clients choices. I then use it in queries to check if a ...
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1answer
99 views

Does this query always correctly retrieve the types of array parameters

The following query seems to work, but I am not sure that it is the best/always correct way: select parameter_name, CASE WHEN data_type='ARRAY' THEN SUBSTRING(udt_name, 2)||'[]' ELSE ...
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1answer
386 views

PostGIS ERROR: operator does not exist: postgis.geometry @ geometry

I have had PostgreSQL 9.3.1 and PostGIS 2.1.0 installed (via https://github.com/PostgresApp/PostgresApp/releases/tag/9.3.1.1-RC1) and working on my laptop for some time, and have been doing Ruby ...
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2answers
86 views

Clobbered default database in postgreSQL

I created a script to drop a particular database and then reload just the structure. I created it using phppgsql. I'm still new to pgsql, so I simply ran the script using \i myCreateScript.sql with ...
3
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2answers
1k views

Database consistency checker in postgresql

Are there any DBCC(Database consistency checker) commands in PostgreSQL? I could find SQL server DBCC commands but not for Postgres? I read that postgresql has inbuilt functionality of perfomance ...
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1answer
46 views

Create a runtime table in PostgreSQL

Suppose that I have two tables: tableA (id, name); tableB (id, name); I also have a textual file with a list of couples of ids: id1a, id2a id1b, id2b ... I would like to run the following query: ...
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1answer
2k views

How to duplicate huge postgres table?

I have huge postgres table (10GB of data - 160M records). Table is static and there are no write operations on it performed. I want to duplicate it, perform writes, reindex it and then with single ...
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1answer
136 views

Retrieve title from rows with a maximum count in other columns

Given the following table archived: CREATE TABLE archived ( sid serial -- row id showurl text -- can be: btg, tmwwt, gcaf, emda title text reference text -- title id ...
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How big of the parameter “shared_buffers” setting on postgresql [closed]

According the document from http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server. Even on a modern Linux system, the stock kernel will likely not allow setting shared_buffers to over 32MB ...
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5answers
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How to efficiently copy millions of rows from one table to another in Postgresql?

I have two database tables. One contains hundreds of millions of records. Lets call that one history. The other one is calculated on daily basis and I want to copy all of its records into the history ...
3
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1answer
931 views

Select row at the nth percentile

I have two tables, table1 and table2. Let the two tables contain date, id and latency column. I have a simple query that performs a join on the two tables and returns a set of rows: Select ...
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1answer
415 views

How can I get data from broken PostgreSQL server? [closed]

I have installed CentOS on a virtual machine and installed the latest version of PostgreSQL server 9.3. I have added PostGIS extension and some data. For some reason, the PostgreSQL service now fails ...