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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Unsupported languages in Postgres Full text search

My web application supports 3 languages, English, Traditional Chinese, Vietnamese. I understand that Traditional Chinese and Vietnamese is not supported in Postgres' Full Text Search. If I were to go ...
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Column doesn't exist in PostgreSQL View

I have the below situation but I don't get what is the problem with my code. I receive this error: column vx1 doesn't exist. vx1 double precision; vy1 double precision; vz1 double ...
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2answers
3k views

Query across multiple schemas, unknown until execution time

I have multiple schemas that I need to query across. The schemas are not known in advance, for example: U111 U222 U333 I need to select across these three schemas from a specific table in each of ...
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24 views

What order do foreign key constraints run in? Why does my foreign key not work after import?

I have two tables tags and tag_memberships in a PostgreSQL database. On the tag_memberships table, I have two constraints. The first is this: ALTER TABLE tag_memberships ADD CONSTRAINT ...
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50 views

Subquery magic in PostgreSQL

I have a query: update product_product set (write_date, default_code) = (LOCALTIMESTAMP, 'update') where product_tmpl_id in ( select distinct product_tmpl_id from product_template ...
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31 views

Minimizing SELECT latency in PostgreSQL

I am evaluating Postgres 9.4 performance on a machine with Intel i7 quad-core 3.6 GHz CPU, 8 GB ram, and 7400 rpm HDD (no RAID) running Linux Mint. The DB schema has the following table: ...
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2answers
42 views

Would like to know why this query is behaving this way?

I have an emp table, with schema and some initial values like below: emp_id | name | last_name | role_id --------+------+-----------+--------- 1 | hell | bell | 1 2 | well | ...
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1answer
20 views

PostgreSQL doesn't log

I'm using ArchLinux and PostgreSQL 9.4.4 and have enabled the logging in the config file: $ sudo egrep -v "^[[:blank:]]*($|#|//|/\*| \*|\*/)" /var/lib/postgres/data/postgresql.conf max_connections = ...
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1answer
155 views

How to speed up ORDER BY sorting when using GIN index in PostgreSQL?

I have a table like this: CREATE TABLE products ( id serial PRIMARY KEY, category_ids integer[], published boolean NOT NULL, score integer NOT NULL, title varchar NOT NULL); A product ...
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2answers
120 views

Is unique index better than unique constraint when an index with an operator class is required

Postgres docs say: The use of indexes to enforce unique constraints could be considered an implementation detail that should not be accessed directly. One should, however, be aware that there's ...
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1answer
34 views

Can column uniqueness be commutative?

I have a table in a Postgres DB where col1 and col2 are foreign keys referring to the same column. I want only unique combinations of (col1, col2), i.e. if (1,2) is entered then (2,1) should be ...
11
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1answer
6k views

Index optimization with dates

I have a large table of objects (15M+ row) in PostgreSQL 9.0.8, for which I want to query for outdated field. I want to divide the query by millions, for scalability & concurrency purposes, and I ...
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1answer
176 views

Postgres automatic failover, multiple clients to multiple masters

I'm looking into providing a method of having multiple hot spare PostgreSQL instances to our website. The majority of implementations that I have found require a single point of failure with PgPool ...
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24 views

Database migration stops halfway through

I've had issues trying to use PostgreSQL so changed my application to use MYSQL. But, when I run rake db:migrate I get the following message before the migration stops: -- PostgreSQL database ...
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1answer
136 views

Why won't pg_basebackup output go to log?

I run a nightly pg_basebackup from a cron job (Postgres 9.3 on debian "wheezy"), but the backup has been failing. It actually creates output, but the .tar file is corrupt and won't extract. I went to ...
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1answer
369 views

Monitoring Amazon RDS with pgtop

I recently migrated a Postgres database to Amazon RDS and I am lacking a good live monitoring tool. I tried pgtop, but I can't get it to work on Amazon. I can see the header with the DB statistics ...
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1answer
171 views

PostgreSQL server problem in Windows XP

2014-10-01 09:22:49 IST LOG: database system was interrupted; last known up at 2014-09-30 18:30:24 IST 2014-10-01 09:22:49 IST FATAL: the database system is starting up 2014-10-01 09:22:49 IST LOG: ...
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1answer
27 views

Index on colum with data type citext not used

In PostgreSQL 9.4, with following schema: CREATE TABLE people ( id INTEGER PRIMARY KEY, name TEXT, junk CHAR(1000) ); INSERT INTO people(id, name) SELECT generate_series(1,100000), ...
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How to do incremental backup every hour in Postgres?

Trying to do an hourly incremental backup of a single Postgres server (Win7 64). I have the following setup in postgresql.conf: max_wal_senders = 2 wal_level = archive archive_mode = on ...
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2answers
939 views

Unnest multiple arrays into rows

I have been shown a great way to bulkinsert with this example: WITH p AS ( INSERT INTO parent_table (column_1) SELECT $1 RETURNING id) INSERT INTO child_table (parent_table_id, ...
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3answers
21k views

Idiomatic way to implement UPSERT in PostgreSQL

I've read about different UPSERT implementations in PostgreSQL, but all of these solutions are relatively old or relatively exotic (using writeable CTE, for example). And I'm just not a psql expert ...
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1answer
20 views

Kibana-like tool for PosgreSQL [on hold]

I'm looking for a tool that could browse and visualize data from db like Kibana does. I'd prefer a native Posgres tool to any that transfers data from a db somewhere else. I know that rivers for ...
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1answer
21 views

Persistant inserts in a UDF even if the function aborts

I have a rather complicated UDF (moves around a bunch of tables as well as creates a bunch of new ones) where multiple aborts may occur. Before every operation I would like to record the time when an ...
4
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2answers
78 views

Avoid unique violation in atomic transaction

Is possible to create atomic transaction in PostgreSQL? Consider I have table category with these rows: id|name --|--------- 1 |'tablets' 2 |'phones' And column name has unique constraint. If I ...
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2answers
129 views

Tuning Postgres for Single connection use? Or is postgres wrong tool?

Any rules of thumb for work_mem, maintenance_work_mem, shared_buffer, etc. for a database that DOESN'T anticipate concurrent connections and that is doing lots of aggregate functions? I'm a social ...
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2answers
5k views

Disable all constraints and table checks while restoring a dump

I've obtained a dump of my PostgreSQL database with: pg_dump -U user-name -d db-name -f dumpfile which I then proceed to restore in another database with: psql X -U postgres -d db-name-b -f ...
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2answers
1k views

How to take pg_dump of a very large postgres database?

I have a production database server running Postgres 8.4 on Cent OS 6.5.The volume of data has increased recently and within few months database now has 18500 tables amounting to approx 350GB database ...
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1answer
119 views

Should database be denormalized if I need an index across multiple tables

I have a catalog of album and song names. The song has a foreign key to the album table. I expect queries like: SELECT * FROM song s JOIN album a ON a.id = s.album_id WHERE LOWER(CONCAT_WS(' ', ...
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16 views

Creating a unique index on a materialized view with no unique columns?

I am using Postgres 9.4. I have created a materialized view from one of my tables and I want to be able to refresh it concurrently. I know from the documentation that in order to do a concurrent ...
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1answer
17 views

Select Distinct on subset of columns, name different set of columns to return

I am using PostgreSQL and have two tables: Table_A colA | colB | colC | colD | colE | colF | colG | colH | colI | colJ Table_B colA | colB | colC | columnD | colE | columnF | colG | colH | colI | ...
5
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1answer
270 views

Rounding issues?

Try this: create table test (f float); insert into test values (330.0); commit; select (8 + 330.0/60)::int; --14 select (8 + f/60)::int from test; --14 select (9 + 330.0/60)::int; --15 select (9 + ...
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1answer
12 views

How to use PostgreSQL bit_or function to aggregate column?

I wish to use PostgreSQL's bit_or function on several rows of a single column of my table, but I can't figure out the proper usage for this. Suppose I have bitwise flags in my column flags, and the ...
4
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1answer
186 views

How to determine cost/benefit of adding an index?

According to Craig Ringer: While it's usually a good idea to create an index on (or including) your referencing-side foreign key columns, it isn't required. Each index you add slows DML operations ...
3
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1answer
55 views

PostgreSQL bytea vs smallint[]

I'm looking to import large (100Mb -- 1 GB) multi-channel time-series data into a PostgreSQL database. The data comes from EDF format files that chunks the data into "records" or "epochs" of typically ...
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1answer
26 views

Use PL/pgSQL in PostgreSQL outside of a stored procedure or function?

I'd really like to use an IF, ELSE construct and execute multiple statements within the IF and ELSE blocks, but I don't wish to save my commands to the database as a stored procedure or function. Can ...
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1answer
28 views

osm2pgsql: select relation member by role

I have a standard postgresql OpenStreetMap database that was filled with data via osm2pgsql. There are different tables for different types (points, lines, polygons, relations) that need to get ...
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1answer
23 views

Add a new collation to a Postgres database

I have these collations: postgres=# select * from pg_collation; collname | collnamespace | collowner | collencoding | collcollate | collctype ...
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1answer
34 views

`chown -R` equivalent for PostgreSQL

We occasionally have the problem that, when upgrading some software and database, inexperienced (or overworked, not excluding myself) sysadmins (we don’t have separate DBAs except for Oracle) run the ...
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I am installing postgres-xl. While initializing the coordinator, i am getting the error below [on hold]

loading PL/pgSQL server-side language ... FATAL: could not open extension control file "/usr/local/share/postgresql/extension/plpgsql.control": No such file or directory STATEMENT: CREATE ...
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2answers
79 views

How to review Database schema?

I am green been software engineer, my team lead give me a task in PostgreSQL database, I need to determine the relationship of the all 405 tables, but the problem is the database doesn't have any ...
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1answer
612 views

Tree structure hierarchical query sorting

I have the following structure of table. CREATE TABLE table1 ( serial_num integer NOT NULL, parent_num integer, parent_key text, key_ary_num integer[], level integer, rank integer, ...
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1answer
761 views

pgpool2 setup on master-slave replication using postgreql 9.1

I have already setup 2 ubuntu server 12.04 LTS on my local machine using virtual box and is using the master-slave replication (postgresql 9.1). 192.168.0.109 = master 192.168.0.110 = slave my ...
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3answers
65 views

Why does connecting to '127.0.0.1' work whilst 'localhost' fails?

I have noticed that although the listening host in postgresql.conf is localhost connecting to a database via psql fails unless the host is changed 127.0.0.1. I have also noticed MySQL display the ...
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0answers
19 views

PostgreSQL: pgbouncer cannot connect to server

I have PG 9.4 running on a given CentOS host: host1, and pgbouncer 1.5.5 running on another CentOS host: host2. Once an hour, some CSV files are downloaded automatically on host2 and loaded into PG ...
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2answers
176 views

PostgreSQL : avoid SUM over same values multiple times

I've a student table and a table of scores in various subjects. I want to sum score1 & score2 for each student across all subjects and then add the bonus for each student. CREATE TABLE student ( ...
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1answer
67 views

Does Postgres preserve insertion order of records?

For example when I'm using query which returns record ids INSERT INTO projects(name) VALUES (name1), (name2), (name3) returning id; Which produce output: 1 2 3 Will this ids point to ...
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1answer
15 views

PostgreSQL 8.4 replication of more than 100 tables

I am facing a problem with PostgreSQL version 8.4. I need to create an slave machine but when I look to all tutorials of slony or londsite its saying I will need to specify the tables that I want to ...
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24 views

Is there an equivalent in postgresql to MySQL's “safe update mode” or “safe delete mode”?

Is there a configuration or flag in PostgreSQL I can turn on to disable bulk updates and bulk deletes, similar to MySQL's "safe update mode" or "safe delete mode"?
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Insert from Another Table + Removing Duplicate Entries in Postgres

I'm trying to insert data from one PostgreSQL table to another while removing duplicate entries but I'm having some trouble with the code. I have two tables I'm working with: mytesttable, which ...
29
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5answers
9k views

Working of indexes in PostgreSQL

I have a couple of questions regarding working of indexes in PostgreSQL. I have a Friends table with the following index: Friends ( user_id1 ,user_id2) user_id1 and user_id2 are foreign keys to ...