PostgreSQL is a powerful, enterprise class, open source RDBMS. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability and data integrity. It runs on all major operating systems, including Linux, UNIX and Windows. It prides ...

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1answer
22 views

Left outer join not returning all columns in a grouping query

I'm trying to query all users to find the price of orders in the last month. I'm doing this on postgresql. Here's a toy database to show my problem: I have a 'people' table and a 'orders' table. I'm ...
4
votes
2answers
748 views

Postgres log files not rotating

I have a postgres system with a hot standby server. They use the same config file. I've setup the log rotation to use log_rotation_size and log_rotation_age so that the master server is rotated every ...
1
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1answer
30 views

Linking first and second level composite primary keys

I am trying to create a new database with a hierarchical structure of two many-to-many tables using composite keys. Unfortunately the creation of tables fails stating that the foreign keys do not ...
1
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1answer
84 views

Should one always VACUUM ANALYZE before REINDEXing in PostgreSQL 8.4?

Early in the morning every day a pgAgent job refreshes the contents of table A from table B on my PostgreSQL 8.4 database. Table A contains around 140k records across 91 columns and has two indexes - ...
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1answer
631 views

What is best strategy for backup on streaming replication(hot standby) environment

I have questions. What is best strategy for backup on streaming replication(hot standby) environment. I’d like to do backup on slave server and restore(PITR). First, I set up streaming ...
5
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2answers
8k views

PostgreSQL: changing password for a user is not working

I installed PostgreSQL on EC2 machine and now I want to change the password of user postgres I do $ sudo -u postgres psql psql (9.1.5) Type "help" for help. postgres=# ALTER USER postgres WITH ...
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0answers
11 views

Bucardo doesn't do fullsync

I have a 2 computers, one of them called master, and the other called slave both using PostgreSQL 9.3.5, but has different OS (32-bit and 64-bit) I have installed and setup the bucardo on the server ...
0
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1answer
31 views

How to order by Levenshtein distance?

I want to order a table according to a char field using Levenshtein distance or similar because some entries may contain underscores or grammar errors. It is a table with all the books I plan to read ...
0
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1answer
47 views

Duplicate records on joining

I have two tables books and books_data. books can have multiple books_data, books_data can have only one book. books_data table has date column by which I want to sort the books table. When trying to ...
2
votes
1answer
895 views

Why aren't unsigned integer types available in the top database platforms?

Databases are usually very customizable with varying data types and custom lengths. It surprises me, as I try to look for the syntax to use unsigned int types that they are not available from neither ...
0
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2answers
89 views

Check if data from database is up to date

I'm storing some data from database, and want to check if that data is up-to-date from the database version. What is the best way to do this? My ideas: Getting checksum from the table and comparing ...
1
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0answers
39 views

SELECT query with DISTINCT on a table-structure for graphs is very slow

I have 2 tables where nodes contains about 60m rows and edges about 500m rows (both growing fast). These two tables represent a directed graph. CREATE TABLE edges ( node_from bigint NOT NULL, ...
1
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1answer
212 views

Upgrading using pg_upgrade on windows fails

When upgrading from postgres 9.2 to 9.3 by following the upgrade procedure found in PostgreSQL 9.3.4 documentation about pg_upgrade, the following command fails: RUNAS /USER:postgres "CMD.EXE" ...
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2answers
22 views

Best way to update the content of large lookups tables

In our application we have a about 20 tables that contain lookup information (read only data that the application doesn't modify). Nightly we'd like to update this information by deleting all the ...
0
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0answers
30 views

How to select column names that contains specific value from other table's column

Suppose I have table items and logs. Both tables have col1, col2, col3, col4... col(n). col1.. col(n) in table items simply specifies key name (col1 = "beef", col2 = "chicken", col3 = "bacon") ...
6
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1answer
654 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 ...
14
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3answers
7k views

Configuring PostgreSQL for write performance

One of my PostgreSQL servers hosts several (1-3) databases which receive a constant stream of data. The data is not particularly structured, it amounts to the current time and a variety of observed ...
2
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2answers
265 views

Updating every cell of of a table?

I have a table with m columns and n rows. The ETL tools I was using wrote an empty ('') to every cell without a value and I would like them to be NULL instead. This got me thinking if it would be ...
1
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0answers
29 views

ORA-00937 when calculating a sub-value in an aggregate select statement

The problem described below applies to Oracle 11g databases. I also tested the statements on MySQL and PostgreSQL with no problems of the kind mentioned in this question. I want to use an ...
1
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1answer
28 views

Change existing column in PG to auto-incremental primary key

I have a database in Postgresql, which was migrated from SQL Server (only data). On SQL Server, a table from this database has these columns: measure_id datum measure where measure_id is ...
0
votes
1answer
16 views

PostgreSQL 9.3 Amazon RDS gives error while using UUID-OSSP extension for generating uuid

I have created DB instance on RDS and used below function it gaves error while with same postgreSQL version on local development machine works fine. create or replace function uuid() returns uuid as ...
2
votes
1answer
40 views

(How) can I return the most specific row on a join?

I'm trying to work out a query that can parse through a table of prices (and exceptions to those prices) to yield the applicable price for a product, ideally using a join. I'm on PostgreSQL. For ...
1
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0answers
28 views

Postgres query plans and tuning parameters

I have a query for which the explain plan indicates that the cost for using a seq scan is lower than the cost for using an index that I have set up. However the actual time for the query is 20 times ...
1
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3answers
95 views

Trigger or Stored Procedure?

Let's say I have two tables, foo and bar: CREATE TABLE foo( foo_id serial NOT NULL, count integer NULL, PRIMARY KEY(foo_id) ); CREATE TABLE bar( bar_id serial NOT ...
0
votes
1answer
33 views

Getting rid of partitioning in Postgresql 9

it turns out that our approach with list partitioning was not the best idea. We have way to much small partitions and a lot of time is wasted on partition choosing by query optimizer. What's the ...
1
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1answer
1k views

Recover PostgreSQL database data

I am using PostgreSQL in my project, Now by mistake I have deleted some records of one of my tables. Now is there any way to recover deleted Records in PostgreSQL?
0
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1answer
44 views

Use if exists in postgresql [closed]

I know about the exists feature, but that does not help me with the given situation. What I want is: Check if some row exists, and if exists then check for an another row if row exists. Here's ...
1
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2answers
599 views

psql: Show current database

In psql I can use \c <database_name> to connect to a given database. How can I see what database I am currently connected to? When I do: my_db> current_database(); I get: ERROR: ...
-1
votes
0answers
15 views

pg upgrade saving database definition taking time

I am in process of a pg_upgrade from 8.4 to 9.3. I am using this technique: http://momjian.us/main/writings/pgsql/pg_upgrade.pdf The upgrade has been running since 250 hours, and it has been on the ...
2
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1answer
28 views

Postgresql: How do full_page_writes help prevent data loss?

From the postgresql docs [full page writes are] needed because a page write that is in process during an operating system crash might be only partially completed, leading to an on-disk page that ...
0
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0answers
18 views

PostgreSQL SELECT and JOIN question [duplicate]

Trying to fix the previous post text formatting issue there was and I did not recognize: I'm using PostgreSQL under ubuntu 14.04. I have two tables as below: create table material_base_name ( ...
0
votes
0answers
11 views

PGBouncer configuration

Let's assume that, for a Django website, I have a PostgreSQL server with only one database in it. max_connections is set to 200. Apart from serving the website, I run each day a local process that ...
1
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1answer
35 views

Tables names in a supertype/subtype schema

I have 3 types of users in my app. The users share some common attributes, but they also have quite a bit of stuff that pertains uniquely to each user type. I have a person table that contains limited ...
0
votes
0answers
26 views

SQL JOIN excluding duplicate

I'm using PostgreSQL under ubuntu 14.04. I have two tables as below: create table material_base_name ( id bigserial, base_name varchar(50), constraint pk_materials_base_name primary key (id) ); ...
0
votes
0answers
27 views

How to deal with finding nearby locations when given a zip code or city?

I am using PostgreSQL and PostGIS for this. I have downloaded dumps from Geoname, and built my tables from allCountries, alternateNames, and countryInfo. I've created my PostGIS geometry column, and ...
1
vote
1answer
39 views

joins with “could be blank” conditions

Question is most probably stupid but I am stuck on this and cant think anymore(Pissed Off). I have these tables-> employee(has a column foreign to location),location and location_flag. And I need ...
1
vote
3answers
59 views

Longest matching suffix while using aggregate functions

Background Looking to find the longest matching string suffix. Setup Consider the following fiddle: CREATE TABLE noun ("label" varchar(10)) ; INSERT INTO noun ("label") VALUES ...
2
votes
1answer
110 views

Why is CTE open to lost updates?

I don't understand what Craig Ringer meant when he commented: This solution is subject to lost updates if the inserting transaction rolls back; there's no check to enforce that the UPDATE affected ...
2
votes
1answer
51 views

Combine a generated series with each row from a select

The below select is returning an array of all the projects owned by all my users. WITH user_projects AS (SELECT u.id as user_id ,COALESCE(array_agg(DISTINCT pa.project_id), '{0}'::integer[]) as ...
0
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0answers
27 views

postgres: access to schema objects within a function

Here's my problem: I have Schema A, owned by User 1, that owns all objects. I've created schema B, owned by User 2. I have granted User 2 all privileges to the objects owned by User 1. When logged ...
1
vote
1answer
14 views

Removing a Key From HSTORE in Postgresql

At the moment I have an hstore that describes the properties of various items. When searching I need to remove values that are unique to a each item (such as serial number, vin, and so on). According ...
1
vote
2answers
102 views

Slow querys on billions-rows-table // index used

Since I'm a young developer and not realy skiled in using databases (PostgreSQL 9.3) i ran into some problems with a project, where i realy need help with. My project is about collecting data of ...
1
vote
1answer
34 views

Proxy authentication for PostgeSQL

The following seems likely to be a fairly common situation, but I haven't seen any solutions. I have a PostgreSQL database containing views that are specific to the $user, in order to restrict data ...
0
votes
1answer
32 views

When is the postgres auto vacuum executed

I am using an older version of postgres(8.4.20). I know that the auto vaccum process is executed frequently to free disk space of queries that deleted or updated data in tables. I have a database ...
5
votes
1answer
13 views

Postgresql 9.1 add nullable column costs more than 10 minutes

I have problems to add a new column on a table. I tried to run it a couple of times, but after more than 10 minutes running, I decided to cancel query because of lock time. ALTER TABLE mytable ADD ...
1
vote
2answers
35 views

SET ROLE via parameterized query

In the very helpful response I received to a previous question, I am trying to write some JDBC code that first sets the role to a specific user before executing subsequent queries. On the safe side I ...
1
vote
1answer
12 views

Postgresql connection refused

I'm trying to remotely connect to my postgresql database. I have two virtual machines set up both running ubuntu 14.04. I am trying to connect to the second vm using the first vm using psql -h ...
1
vote
1answer
34 views

Upgrading 8.1 to 9.3 - using statement log and WAL to check compatibility?

We're migrating from postgres 8.1 to 9.3, since we need streaming replication badly. All the application developers have deserted the company a long time ago, way before my time here, so there is ...
1
vote
1answer
113 views

PostgreSQL's Query Hierarchical data poor performance

Badly need some technical assistance on this query performance issue I'm working on. Summary of the data structure is: 1 project has many homeprofiles, 1 homeprofile has many tasks, 1 task has many ...
1
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2answers
15 views

manual execution of specific remote query with postgresql_fdw

In 9.4b2, postgresql_fdw doesn't know how to "push down" aggregate queries on remote tables, e.g. > explain verbose select max(col1) from remote_tables.table1; ...