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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Partial unique constraint spanning multiple tables in postgres

To enforce partial uniqueness in postgres, it is a well known workaround to create a partial unique index instead of an explicit constraint, like so: CREATE TABLE possession ( possession_id serial ...
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0answers
26 views

Copying Python data types to Postgres [migrated]

I feel like this is a very basic question, but I cannot find a comprehensive answer on this. I am wondering what is best practice for copying python data types, like lists or dictionaries, to a ...
1
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1answer
109 views

difference between pg_dump command's --column-insert and --attribute-insert

Background: I'm trying to create a dump file that only contains the data in my database. I would like it to create the data with the INSERT command. In reading the manual, ...
3
votes
1answer
176 views

Problems restoring backup from base backup + WAL with WAL-E

I'm trying to do nightly restores of the main database on a separate node. I want to do weekly full restores and nightly restores by consuming the latest WAL files. On the master I have wal_level = ...
2
votes
1answer
979 views

How to configure pgpool for reasonable speed

I have a problem with pgpool II configured in master-slave mode with replication on slony. I have configured postgres databases on each server to run as fast as they can and this was verified by me ...
0
votes
1answer
679 views

Configuring Postgres 9.2 streaming replication with Redhat Clustering Suite for High Availability

I'm in the process of configuring PostgreSQL 9.2 streaming replication with Redhat Clustering Suite for high availability. I have 1 master and 1 hot standby configured to replicate the data from ...
0
votes
1answer
49 views

Divide a PostgreSQL database into schemas

My Postgres database will be focused on multidisciplinary organizations. The project axis is: a person could belongs to diverses disciplines (ex: arts, sports) for the same organization, and this ...
2
votes
2answers
131 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; ...
2
votes
1answer
47 views

postgresql - how and why indexes are bigger than their tables

I'm using postgresql 9.3 and trying to understand how and why indexes are bigger than their tables. Sample output: database_name | database_size | table_name ...
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0answers
10 views

How can I create a copy of postgis db from one windows machine to another

I have postgres 9.3 database with postgis extension. I want to create a new database on different computer and import all the tables from the source database. In mssql it would be simple , just ...
0
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1answer
235 views

pg_basebackup giving “could not receive data from client: Connection reset by peer”

I'm trying to get data to a new slave box from my new master (previously the slave). I've tried the steps already and it worked previously. Now when I run the following command: pg_basebackup -h ...
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1answer
29 views

How to setup path to access psql from command line in Mac [closed]

psql does not work even path was set .bash_profile. Path was set export PATH=/Library/PostgreSQL/9.4/bin:$PATH in .bash_profile.
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2answers
136 views

Limiting read access in postgres to few rows

We have a requirement where we want to limit the maximum no. of rows that a select query can return when its done using a particular login. So basically we would like to append a limit clause to any ...
0
votes
1answer
26 views

Backup-strategy for redundant data in postgresql-db.

I have a (postgresql-9.3)-table that contains images as a bytea-column as well as several other columns that contain extracted information from these images. (Some feature points, descriptors). These ...
2
votes
3answers
49 views

What schema for different relation from two tables to another?

There are three tables instructors, meeting_points and bookings. Here are the relation I want: 1 instructor has 0, 1 or n meeting_points 1 booking has 1 meeting_point 1 meeting_point can be linked ...
5
votes
0answers
40 views

Bulk insert M:N relation in PostgreSQL

I need to import data from an old database to a new one, with slightly different structure. For example, in the old database, there is a table recording employees and their supervisors: CREATE TABLE ...
1
vote
1answer
48 views

Is there a way to add a column to a table without affecting performance?

How do you add a column to a table in production without affecting its performance? Or is this impossible? I'm asking about Postgres.
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2answers
45 views

Calculate number of consecutive years (not gapless)

I have a request that wants to look at numbers of consecutive year buyers. For example, I have a table like this: Order_year, Contact 2015, 123 2014, 123 2013, 123 2011, 123 2010, 123 2015, 234 2014, ...
2
votes
1answer
38 views

How do I prevent my query from needlessly generating rows it'll throw away later?

I have the following query: SELECT stream_points.time AS point_time, stream_points.value AS point_value, stream_predictions.value AS prediction_value, ...
0
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2answers
46 views

Approach to take regarding a field that is frequently re-computed

I have a few fields with text data in a main table which is processed in a certain way to produce a processed version of that piece of text. Now, the way in which this text is processed is expected ...
0
votes
1answer
123 views

11.2GB text file import MySQL or PostgreSQL

I am out of my depth a bit perhaps but submit this query hoping someone has some experience importing large (11.2GB) tab delimited text file (2.2GB tar.gz file) into either MySQL 5.5.41 or PostgreSQL ...
0
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1answer
64 views

Postgresql Hot Standby - How to determine it's fully mirrored?

I have set up a hot standby of a postgresql server. It all seems to be working, but I just want to be sure that I'm not missing something. In /var/lib/pgsql/9.2/data/pg_log/postgresql-Wed.log I have ...
0
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1answer
416 views

pgpool2 not working on my Ubuntu i686 athlon i386 GNU/Linux

I am trying to implement replication and load balancing on my Ubuntu i686 athlon i386 GNU/Linux.for creating database clustures I have installed postgresql contrib 9.1.11 having initially database ...
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0answers
25 views

Replicating table level PostgreSQL 64bit windows

I need to replicate some tables on PostgreSQL 64bit for Windows (master -> slaves replication model) and I can't find any tool that can achieve that. Slony-I work very well for PostgreSQL 32bit for ...
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0answers
23 views

What does `@@` mean in a PostgresSQL query? [migrated]

What does the "at symbol" mean in a PostgreSQL query? For instance, I'm looking at a query where a WHERE condition is: WHERE (to_tsvector('german', nodes.name) @@ plainto_tsquery('german', 'münd')) ...
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559 views

Postgres database zero down time production deployment

I need some idea about how I can deploy a financial application in production environment using PostgreSQL DB with zero down time. I have two servers in Master-Slave design. Currently I am giving ...
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1answer
1k views

PostgreSQL : drop column from view

I have a VIEW where I'm attempting to create an evolution script for, so I can add a column to it. That part works fine; column added just fine. However, the reverse does not work; remove that last ...
0
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1answer
986 views

How to add FK on a column of composite type in PostgreSQL?

I have a table which contains a composite type and I am trying to connect a column of it to another table's PK. CREATE TABLE aaa (col1 SERIAL PRIMARY KEY); CREATE TYPE bbb AS (col2 INTEGER); CREATE ...
2
votes
1answer
23 views

Querying on multiple joined rows

I have a table called visits that is structured like so: +----+--------------+-------------+ | id | name | visitor_id | |----+--------------+-------------+ | 1 | event1 | 1 ...
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2answers
2k views

postgres service suddenly not working after the computer crashed while working

I've been working with postgres on a linux server for the last couple of months. Last week, half of our servers crashed and my one with them. I was in the middle of uploading data to the postgres ...
0
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1answer
32 views

Postgres lose xlog

I have 2 instances master-salve postgres run on AWS, the xlog folder is on ephemeral disk. The master instance was down, so I lose the xlog folder, Now, i'm trying to start up the master again and ...
2
votes
1answer
2k views

PgPool 2 with HA Proxy

So, I'm looking to add high availability to a postgresql server. I've looked into some tutorials on the web but, haven't been able to find exactly what I'm looking for. E.g.: PostgreSQL ...
0
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1answer
23 views

Postgres INNER JOIN same table failing on CartoDB

I have a table with data which looks like this +----+------+-------+ | cp | year | count | +----+------+-------+ | 1 | 2000 | 10000 | | 1 | 2001 | 9000 | | 1 | 2002 | 9500 | | 2 | 2000 | 8000 ...
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5answers
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SELECT DISTINCT on multiple columns

Supposing we have a table with four columns (a,b,c,d) of the same data type. Is it possible to select all distinct values within the data in the columns and return them as a single column or do I ...
3
votes
3answers
37 views

PostgreSQL GRANT ALL on mutliple tables using LIKE

I have more than 100 tables named public.test_* How can I easily GRANT ALL access to the user test to all that tables at once? I tried with: GRANT ALL ON TABLE public.test_* TO test; But it is ...
3
votes
2answers
480 views

PostgreSQL 9.3: Index on to_char()

How can I index a to_char() of a column? I have tried: adam_db=> CREATE INDEX updates_hourly_idx ON updates (to_char(update_time, 'YYYY-MM-DD HH24:00')); But got the error: ...
2
votes
1answer
63 views

Best index for similarity function

So I have this table with 6.2 millions records and I have to perform search queries with similarity for one for the column. The queries can be: SELECT "lca_test".* FROM "lca_test" WHERE ...
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0answers
29 views

User with Read Only access on a particular schema- PostgreSQL

I wanted to know if I can make a read only user usr1 on schema sch1 in database db1. In addition, I want that this user not to have any access to anything else in this database (not even read access ...
0
votes
1answer
217 views

Pros and cons of using many schemas in PostgreSQL as opposed to just one?

For a large SAAS application (backed by PostgreSql 9.4), with over 300,000 accounts (and growing), what are the pros and cons of using a schema per account to partition the data vs putting all the ...
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0answers
1k views

Upgrade Postgres 9.3 to 9.4 after Ubuntu 14.04 to 14.10 upgrade

I've just recently upgraded my Ubuntu install from 14.04 to 14.10. This automatically pushed Postgres 9.4 onto the system. I'm trying to migrate my cluster like this: sudo pg_dropcluster 9.4 main ...
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0answers
45 views

compound index not being used on simple query

I'm running this query, and it seems to be doing a table scan , rather than using the relevant index.. select count(*) from pages where charity_id=447 and provider_id=1 this is the explain: ...
0
votes
0answers
12 views

PostgreSQL 9.3 - Move table to tablespace - Slow?

I need a help with moving table to a different tablespace. I have a really large table that is not queried much often so I've decided to move it from tablespace on SSD to tablespace on HDD and save ...
0
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0answers
45 views

PostgreSQL query taking a long time

I have a query that is taking hours to run. There is a large table to parse, is there any way to optimise this? with VehData as ( SELECT * from dblink('host=databasesrv port=1234 ...
2
votes
1answer
110 views

PostGIS: Cutting Holes in Self Geometry

I have a table of geometries in PostGIS, some of which overlap. When I display the geometries, this has the unfortunate consequence of blending the two stacked geometries together and producing an ...
0
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1answer
218 views

Postgres DB - Commit xlog files after server crash

After a server crash, it would seem that all transactions going back a number of months are not showing up in the live Postgres DB. Investigation has found all xlog files that does contain the data ...
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2answers
157 views

PostgreSQL : dependencies on a schema

I need to delete a schema in my PostgreSQL database. I would like to make sure that the schema is not used in another schema (for instance : this schema is used for a view in another one). Is there a ...
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1answer
35 views

Count number of duplicate rows, sort from most to least (statistic) [closed]

I'm trying to make statistic of top-10 most visited URL. I have one simple table. For each URL visit, one row added with that URL as content. Most visited URL has the most number of duplicate. I've ...
1
vote
1answer
38 views

generate new column from another table column, treating nulls are unique

I have a table that looks like the following: |device_id | login_id | ----------------------- | 1 | NULL | | 2 | A | | 3 | A | | 4 ...
1
vote
1answer
79 views

Syntax error using preparedstatements with postgresql

I have a Java application connecting to a PostgreSQL database. Using straightforward code like: ps = con.prepareStatement(sql); if (dataTypes != null && dataTypes.size() ...
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0answers
28 views

PostgreSQL GUI Tools with Git repository integration [closed]

I'm currently evaluating PostgreSQL GUI tools that have following capabilities: Query Editor GIT Repository Integration for version control Change script generation for deployment between the GIT ...