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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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1
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0answers
126 views

Connecting Posgresql server using Pgpool

I am running two postgresql servers on two different linux machine and also running the pgpool-II-93 on the both machine.I simply want to check whether syncing between Databases at different machine ...
0
votes
1answer
84 views

What happens when we call pg_dump while users are still using the system?

We have a web application with PostgreSQL as our database and use celery background tasks for somewhat complex task. At the very beginning of this complex task we take a backup of the database using ...
1
vote
1answer
226 views

PostgreSQL - Out of memory on count group by query

I'm trying to execute the following statement in PostgreSQL database: create table tmp_nodes as select node_id,count(way_id) as count from way_nodes group by node_id; This query fails because the ...
0
votes
0answers
60 views

Adding additional condition significantly degrades performance

Have the following query: SELECT * FROM table_A INNER JOIN table_B ON /* conditions */ INNER JOIN table_C ON /* conditions */ INNER JOIN table_D ON /* conditions */ WHERE table_B.state = 'active' ...
1
vote
1answer
653 views

Difference between now() and current_timestamp

In PostgreSQL, I use the now() and current_timestamp function and I see no difference: # SELECT now(), current_timestamp; now | now ...
0
votes
1answer
103 views

Database design for small startup

For a small startup that doesn't have much expected traction in the very beginning. We are currently working with only one postgres database without replications and at risk of failures. I've done ...
4
votes
0answers
250 views

Postgresql JDBC Table Valued Parameters [closed]

MSSQL has a great feature called Table Valued Parameters. It allows you to pass a table of a custom data to stored procedures and functions. I was wondering what is the equivalent in PostgreSQL, if ...
2
votes
2answers
495 views

Returning empty string when string_agg has no records

I am trying to return a text field in a PostgreSQL query that is of the form 'stringOne' || string_agg(field, ',') || 'stringTwo' where for certain elements in the group clause, field is always ...
2
votes
1answer
84 views

How to create function(table_name) that returns a set of the table

I have a set of tables that share the same fields (some timestamps and users names used for version control). I need to create a function with dynamic sql that uses a table_name and a timestamp as ...
0
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0answers
79 views

How to pass log file in pg_dump

I am using this command to export. export PGPASSWOD=${PASSWORD} pg_dump –i –b -o -host=${HOST} -port=5444 -username=${USERNAME} -format=c -schema=${SCHEMA} --file=${SCHEMA}_${DATE}.dmp ${HOST} ...
0
votes
1answer
53 views

Merge left outer join column

I have a query that use left outer join. something like that : select issues.id, journal.notes from issues left outer join on (issues.id = journal.issue_id and journal.notes != '') So far it ...
1
vote
4answers
1k views

PostgreSQL 9.3 on Ubuntu Server 12.04 v.s. MS SQL Server 2008 R2 on Windows 7 Ultima

I have searched many articles in Google about the performance of PostgreSQL vs MS SQL 2008 R2 and found that many of those articles say the performance of PostgreSQL is better than that of MSSQL 2008 ...
1
vote
0answers
185 views

Is there a psql equivalent of bash's reverse-search-history?

I am very fond of bash's reverse-search-history (C-r) (command-line feature): Search backward starting at the current line and moving ‘up’ through the history as necessary. This is an incremental ...
1
vote
1answer
244 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, ...
1
vote
2answers
436 views

postgresql being slow on count distinct for dates

I have a very simple, but very big, table. Its schema is like this (yadda int, yadda1 int, yaddate date, ... other stuff). Now, yaddate has an index by itself and it is also in other indexes ...
0
votes
1answer
603 views

Unable to Start PostgreSQL. kernel's SHMMAX parameter exceeded you limit

When I am trying to start my PostgreSQL I get the following error in the Postgresql.log file: FATAL: could not create shared memory segment: Invalid argument DETAIL: Failed system call was ...
0
votes
1answer
66 views

Postgresql condition on subquery results

This is a new question based on the solution to my previous question I have the following tables: users int (pk) user_id date last_visit int (fk) local_site sites int (pk) site_id site_stats ...
-1
votes
1answer
276 views

Insert a file into PostgreSQL BYTEA field using PHP

The previous answers have been horribly complex for the scope of this project. I want to take the $_POST result as a variable and insert it into a BYTEA field of a table. $_SESSION['username'] = ...
2
votes
1answer
221 views

Postgresql not using GIN trigram index when performing non-ASCII LIKE query?

Steps to reproduce Create database CREATE DATABASE citiesdb WITH OWNER = citiesowner ENCODING = 'UTF8' TABLESPACE = pg_default LC_COLLATE = 'C' LC_CTYPE = 'C' ...
0
votes
1answer
319 views

While importing 150 GB file on Amazon RDS, why connection is failing?

I am having Postgres database dump file of 150 GB on Amazon EC2 instance. While dumping the data on RDS from EC2 server I am getting error. The output of the command is as given below. It's giving ...
2
votes
2answers
87 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 ...
0
votes
0answers
55 views

Update query taking 8x times in hot standby environment of Postgresql

I configured streaming replication (hot standby) and tested the update query on it. The update query is taking 8 times more when compared with stand-alone PostgreSQL (9.2 version) system. Some ...
2
votes
1answer
92 views

Recovering a partial PostgreSQL archive

I have $PGDATA/base but nothing else. It was taken from an installation after the postgreSQL service was shutdown, so is clean. Is there any way to recreate the other elements in $PGDATA that allow ...
2
votes
1answer
258 views

How do I sort the results of a recursive query in an expanded tree-like fashion?

Let's assume you have a nodes tables like this: CREATE TABLE nodes ( node serial PRIMARY KEY, parent integer NULL REFERENCES nodes(node), ts timestamp NOT NULL DEFAULT now() ); It ...
2
votes
2answers
197 views

How slow is slow in postgres?

I'm working with postgres for the first time. I have a lot of experience with small / medium size data analysis (i.e. things that fit in ram and can be analyzed in R, Stata, Matlab, etc.), but am now ...
1
vote
1answer
141 views

What's better here - a single column or multicolumn primary key?

Let's assume you have a table groups and a table item. Each item belongs to exactly one group. It is an inherent part of that group. An item cannot exist outside of a group and it cannot be moved to ...
2
votes
1answer
156 views

Why write ahead logs in PostgreSQL are generated every second

PostgreSQL version 9.2 generates write ahead log (WAL) every second i.e. 60 WALs are generated in one minute. Is it possible to make them occur less frequently? Is it possible to increase the WAL ...
1
vote
1answer
301 views

Increased performance from single statement, multiple row inserts?

I'm currently obsessing over bulk inserts via prepared statements with libpqxx. I am far from a database expert and even further when it comes to Postgres, but just thinking superficially, it doesn't ...
0
votes
1answer
84 views

PostgreSQL extending UPDATE query

I have the following update query to populate a table storing user stats users: int (pk) user_id date last_visit int (fk) local_site sites: int (pk) site_id site_stats: int (fk) site_id ...
3
votes
0answers
91 views

Is PostgreSQL or ElasticSearch/Solr the right tool for this kind of query? [closed]

Here is an example of the current PostgreSQL query: SELECT a.*, a.al_location <-> '(someLon, someLat)' AS d FROM al_app.al_activity AS a WHERE to_tsvector('simple', a.al_keywords) @@ ...
1
vote
1answer
321 views

Select query for returning different data based on creation time

I have a view, which will Select data from table reports the select will filter the data based on multiple dates. reports table: id, key_id, position, created_at My select: pr.key_id, ...
0
votes
0answers
52 views

Postgresql not working: error

My Postgres was working fine on my ubuntu 12.10 before i installed postgres-xc and execute a command initdb for changing encoding. After that it started showing error like: psql: could not ...
3
votes
3answers
405 views

PostgreSQL 9.0 how to reclaim disk space after delete without rebuilding table?

Our PostgreSQL 9.0 Windows production server is running low on space. In our 100GB database, we have a large table containing TOASTed binary data. We have deleted some rows and need to return the ...
0
votes
1answer
402 views

postgresql bigserial or sequence using jpa

I'm a java developer working with jpa, before to define the indexes in my entities i would like to known which one is faster o better to use?.
1
vote
1answer
107 views

Adding unsigned 256 bit integers in PostgreSQL

I was wondering if there would be any way to do the following in PostgreSQL: UPDATE cryptotable SET work = work + 'some big hexadecimal number' where work is an unsigned 256 bit number. Right now ...
1
vote
0answers
120 views

Data Corruption on base backups created with wal-e?

I have streaming replication setup on Postgresql 9.1 with two machines on AWS EC2. The master has a cron job that does a daily base backup using the wal-e tool and uploading it to Amazon's S3 storage. ...
0
votes
1answer
969 views

Using dynamic column names in PostgreSQL

I am using PostgreSSQL 8.3. I want to execute this query: select COALESCE(col_fr,col,'Unknown') from my_table where id = 'abc'; Twist in the story is column name colum_fr should be generated ...
-1
votes
2answers
172 views

Select records for a day and a day - 1 day

From one table, I want to get the records from one column position when the created_at = Today and when the created_at = created_at - 1.day COALESCE(array_agg(DISTINCT pr.position)) AS position, ...
1
vote
1answer
437 views

How to Configure PostgreSQL Hotstandby Automatic Failover

So I have configured two postgeSQL servers to have hotstand by streaming, now my question is, how can I configure it so that when the master server goes down, the slave server will become the new ...
2
votes
1answer
29 views

What is the “last” data that get's backed up, when running pg_dump on a live server?

I'm wondering: If I start doing a pg_dump of a very large database (it would take hours), that is still running actively receiving writes, what is then the last data that goes into the backup? Is it: ...
1
vote
1answer
456 views

log_min_duration_statement setting is ignored

I am running Postgresql 9.1 on Ubuntu. Exact Postgresql version is 9.1+129ubuntu1 as my package manager shows. I have 2 databases that are actively in use and they are used from a remote server. I ...
5
votes
2answers
490 views

PostgreSQL, integer arrays, index for equality

I have a huge list of integer arrays (300,000,000 records) stored in Postgres 9.2 DB. I want to efficiently search these records for an exact match (equality only). I have heard of the intarray module ...
3
votes
1answer
93 views

What does “ERROR: failed to find parent tuple for heap-only tuple at (1192248,5) in table ”fruits“” mean?

After being bitten by the bug mentioned in the release notes of 9.3.4, I have realized that a very small part of my data is corrupt, after doing a failover. The bug showed it self as duplicate rows, ...
0
votes
1answer
45 views

Why is it not possible to alter a view with a “CREATE OR REPLACE”?

The Postgresql documentation is clear on this point: you can not change the columns of an existing view. The new query must generate the same columns that were generated by the existing view query ...
3
votes
2answers
533 views

Postgres Streaming Replication lagging, using lots of CPU and little I/O

We have 2 dedicated DB Servers. One is master and other is its streaming slave. Postgres version 9.0.17. We have similar hardware on both servers and using 15krpm SAS drive in Raid 10 for Database ...
4
votes
1answer
352 views

How to apply a patch in PostgreSQL on Windows?

How to apply a patch in PostgreSQL? I found an advice, but it seems to be suited for *NIX only. My PostgreSQL (9.3.1 EDIT: 9.3.4 now) was installed from an exe installer on Windows XP (32 bit), so I ...
1
vote
1answer
163 views

How do I validate all my constraints in postgresql?

It seems like I have been bitten by the first bug described in the release notes of postgresql 9.3.4: http://www.postgresql.org/docs/devel/static/release-9-3-4.html I now have e.g. duplicate primary ...
2
votes
1answer
142 views

Why does my table hold duplicate primary keys?

To my big (and worrying) surprise I just realized that my table with millions of rows, has a few handful of rows, where the primary key (ID) is a duplicate! I don't understand how this can ever ...
0
votes
1answer
506 views

Installing pgcrypto Extension

I have this password hash function that hashes a password to sha256. I've already got it running in pgadmin3 in a local database. I've done it by importing the extension, a feature that has been added ...
0
votes
0answers
38 views

Organizing a couple tables in postgresql

I have a data structure that is represented like this: { 'question_id': 1, 'is_required': False, 'question_text': [ { 'id': 1, ...