Questions tagged [postgresql]

All versions of PostgreSQL. Add an additional version-specific tag like postgresql-11 if that context is important.

Filter by
Sorted by
Tagged with
10
votes
3answers
3k views

Efficiently comparing prices in different currencies

I want to make it possible for user to search products within a price range. User should be able to use any currency (USD, EUR, GBP, JPY, ...), no matter what currency is set by the product. So, the ...
1
vote
0answers
1k views

PostgreSQL pg_bulkload query eats all free disk space

I have a simple task: bulk insert csv file to the table. The .ctl file is TYPE = CSV # Input file type ESCAPE = \ # Escape character for Quoting ...
14
votes
1answer
13k views

How to determine the sweet spot between pool size and database connections in PostgreSQL

We are having trouble handling the traffic during peak hours to our database server. We're looking into improving the hardware (see this question about that side of things) but we also want to work on ...
2
votes
1answer
1k views

Error creating index on PostgreSQL 9.1

I have a process where user A creates a table and user B tries to create an index on the new table, owned by A. Users A and B are from the same group but user B is an automated process. Is it ...
4
votes
1answer
1k views

High availability in postgresql

We will be switching from mysql cluster to either postgresql or oracle (with RAC). Mysql cluster is quite reliable, but lacks features in SQL that make programmers life easier (they consider it as ...
7
votes
2answers
2k views

SQL ANSI JOIN precedence

I have a query that looks like this: SELECT * FROM TBLA A LEFT JOIN TBLB B ON A.Col1 = B.Col2 RIGHT JOIN TBLC C ON B.Col3 = C.Col4 JOIN TBLD D ON C.Col5 = D.Col6 In which order will ...
3
votes
1answer
1k views

“Zero” downtime and minimal space requirements for upgrade to PostgreSQL 9.2

Need to migrate from PostgreSQL 8.3.x to 9.2 Constraint 1: 8.4 and above have made datetime format to be integer by default. Wasn't so in 8.3.x. As a result pg_upgrade can't be used. Unless server is ...
1
vote
1answer
2k views

PostgreSQL 9.1 - Asynchroneous commits performance boost

During peak hours our users experience a lot of timeouts due to an overloaded database server. We are currently trying to make optimizations in order to cope with the high traffic. We read in the ...
1
vote
1answer
2k views

Can't start postgres server, SHMMAX too small

When I try to start the postgres server with sudo /etc/init.d/postgresql start I get this error: Starting PostgreSQL 8.4 database server: mainThe PostgreSQL server failed to start. Please check ...
2
votes
1answer
441 views

postgresql pgadmin3 queryconnect attribute does not work

I'm using Fedora 17 and pgadmin3 to auto-connect to a postgresql database with one button click. Every time I want to run an SQL statement, I have to do 4 steps, (open pgadmin3), (connect to the ...
1
vote
2answers
644 views

How to remove tables and indexes?

I've a file with the SQL statements to create tables, indexes, etc, and another file with data test to use in the test database. Then, I want that they can be removed. How to remove table and indexes ...
2
votes
1answer
458 views

PostgreSQL asynchronous replication (and possible data loss)

I'm trying to wrap my head around Postgres' asynchronous replication. The way I'm reading the documentation, if the master goes down after data was committed, but before it's shipped to slaves, the ...
6
votes
1answer
4k views

Check what event called the trigger on PostgreSQL?

I'm trying to check what event called my trigger, like INSERT, UPDATE or DELETE. Oracle triggers can check this in a simple 'IF' statement: IF INSERTING, IF UPDATING or even IF DELETING Is there a ...
3
votes
1answer
172 views

query discrepancies on very large postgres table

I have a fairly large table (25m entries) which stores tracking data, I am not a postgres admin by trade so this may be a simple problem. these two queries although similar are taking massively ...
7
votes
2answers
1k views

PostgreSQL: Query DB for rows containing integer[] > or < than specified value

I have a table which stores historical temperatures for the past 5 days stored in an integer[] column based on city. The question is: How can I query for entries which have a value great than or less ...
1
vote
1answer
785 views

Search for null in id column over all tables programmatically

I want to automatically check for null ID's over all id columns in my database, I have to check all tables of which there is about 50,000 so manually doing this is infeasible
1
vote
1answer
482 views

Postgres replication/replication to server outside firewall

I am looking for a way to have a postgresql database (running server version 9.1) replicated. I want the mirroring to be able to have one server (the slave) standing outside our firewall. I have been ...
8
votes
2answers
3k views

How to wait for PostgreSQL to be startable / restorable?

I'm testing a PostgreSQL 8.2.1 to 9.2 upgrade on a virtual machine running a custom Linux distro. The upgrade procedure is as follows: Start the pg service Vacuum all DBs (not sure if this is needed) ...
3
votes
1answer
1k views

How to wait between PostgreSQL DB restore and reindexing?

I've written a script to upgrade PostgreSQL from 8.2.1 to 9.2.1 on a Linux From Scratch distribution: Start the pg service Vacuum all DBs (not sure if this is needed) Backup with pg_dumpall Stop the ...
2
votes
1answer
2k views

PostgreSQL - How can I manage WAL archiving for different databases on a server?

I'd like to use WAL archiving for incremental backup of my database. But I have 2 databases on my server, and I can't afford the disc space for backup of both of them. So I only want to backup one of ...
0
votes
1answer
412 views

Can't access Brew PostgreSQL

I've used Brew to install PostgreSQL. I want to log in with psql. Since I haven't set a password I 'm trying to login without one. When I try I get this: psql: fe_sendauth: no password supplied I ...
5
votes
1answer
707 views

Storing application settings with different datatypes

I'm developing a web application and I plan to store application settings in the database in name,value fields (one row = one setting). These settings range from directory paths to simple yes/no ...
3
votes
1answer
1k views

Model with variable number of “properties” of different types.

I would like to have a table of microscope slides, where on top of the basic id, name,date_created would each slide also have a number of editable "properties". Imagine one slide having ...
8
votes
2answers
1k views

High Availability for postgresql

I'm new in PostgreSQL database. Recently our developer needed to do some upgrades in our systems. Because of that we are planning to implement some method in order to implement database failover. ...
2
votes
1answer
3k views

Recommendations for PostgreSQL training [closed]

I'm looking for recommendations for PostgreSQL training (on-site, off-site, remote) that covers administration, performance optimization, and clustering solutions like Slony and pgpool. Finding ...
9
votes
2answers
961 views

PostgreSQL PITR restore

I have a PostgreSQL 9.1 server running on a CentOS 5.8 32bit OS and I have enabled WAL archiving. On this server, there are three databases: databaseA, databaseB and databaseC. Someone deletes a ...
4
votes
3answers
15k views

Copy PostgreSQL data from one PC to another

I am migrating my server application from the existing system to another system. Unfortunately, the existing system is also the database server. It has data stored. Is it possible to copy this data to ...
6
votes
1answer
12k views

Getting a random row from PostgreSQL?

I want to get a random row from my table by id. My table: ID|Word |Dificult|Category_id| 1 |'Dumb' |'Easy' | 3 | 2 |'Leopard'|'Medium'| 6 | If my user selects a category and ...
5
votes
2answers
3k views

How do I implement insert-if-not-found for transactions at serializable isolation level?

I'm having a hard time figuring out how to exactly implement a 'insert if not found' function. Consider the following. We have a table called artist with 2 columns, (name, id) where name is the ...
5
votes
1answer
455 views

Database Exceptions with Jetty 8.1.0 with BTM

We are running Jetty 8.1.0 with BTM 2.1.2. We are using Postgres as our DB. Everything works great except that when we run any query with a condition where sometable's primary=null, the server loses ...
3
votes
1answer
191 views

Does updating a partially indexed field add or remove it from an index in Postgres

We can create a partial index for a field in Postgres. I am looking at using this to stop rows which are archived from being in an index on a created_at field: First we create the index: test=# ...
32
votes
3answers
30k views

Is it a good idea/approach to index a VARCHAR column?

We're using PostgreSQL v8.2.3. There are tables involved: EMPLOYEE and EMAILLIST. Table 1: EMPLOYEE (column1, column2, email1, email2, column5, column6) Table 2: EMAILLIST (email) 2 tables are ...
1
vote
1answer
719 views

PG_bulkload utility postgresql need help

i am using COPY command to export the data to the out file with changes made to the data before export using option ST_asBinary() using command COPY ( SELECT st_asBinary(geom) FROM n_america ) TO ...
3
votes
1answer
2k views

create index - invalid memory alloc request size

i get this error "invalid memory alloc request size 18446744072635840654. SQL Status:XX000" when i want to create an index. The Table looks like this: CREATE TABLE schema.tblname ( id bigint NOT ...
3
votes
1answer
1k views

Does the pgpool-II extension allow for parallel execution of any query?

I read about pgpool-II here and it states that: Using the parallel query function, data can be divided among the multiple servers, so that a query can be executed on all the servers concurrently to ...
3
votes
1answer
150 views

Optimising query on view that merges similar tables with a clear discriminator

Using PostgreSQL 8.4, I have a number of tables that have a very similar structure, but that belong to different categories: CREATE TABLE table_a ( id SERIAL PRIMARY KEY, event_time TIMESTAMP ...
4
votes
1answer
1k views

PostgreSQL psql command line tool and SET CONSTRAINTS DEFERRED

I am using PostgreSQL 9.1.5 and the psql to run a scipt containing a series of INSERT statements in various tables: psql -U usernamefoo databasenamefoo -f dml_script.sql The table constraints have ...
5
votes
1answer
1k views

How large should my pool size be? And should I use pgbouncer?

I have a Rails application with 4 Unicorn workers. How do I determine what postgresql database pool size I should use? And if I have 6 applications connecting to this postgres database, would that be ...
2
votes
2answers
3k views

Select rows with repeat data within certain timeframe

As a follow-up question to my previous question on difficult row categorisation, I have another problem which I'm sure will be easily solvable. After this I plan on reading a good book or two on ...
1
vote
1answer
1k views

PostgreSQL 8.4 hangs on create table, reindex

I have a rather small database(200Mb) which was running on ubuntu 10.10/amazon ec2 fine for a year almost but today I ran into the following problem: When I create a table that references other table ...
3
votes
2answers
1k views

Is the speed of a PostgreSQL SELECT adversely affected by too many indexes on the table?

I have read that when having a lot of indexes on a database It can seriously hurt the performance but in the PostgreSQL doc I can't find anything about it. I have a very big table with something like ...
2
votes
1answer
125 views

How to recover the database with old data?

I am using PostgreSQL. I have 4 database servers. Each server has same database and same schema. Mistakenly I restored the database util05db backup onto the util01db database. How can I get the ...
-2
votes
1answer
3k views

Insert a 'null' string in a table in postgresql [closed]

I would like to know if it is possible to insert a 'null' string in a column which has NOT NULL constraint. I'm using postgresql. The query would look like the below INSERT INTO originators(...
15
votes
1answer
3k views

Choice of authentication approach for financial app on PostgreSQL

First some background. The LedgerSMB project is an open source financial accounting software project that runs on PostgreSQL. We implement a very large amount of business logic in user defined ...
3
votes
1answer
340 views

PostgreSQL synchronized commit performance

I'm setting up a pair of PostgreSQL servers. Because cash is short I can only afford one high class server and some crapy backup box. If the expensive high end box should catch fire, operations can ...
3
votes
1answer
2k views

Working across multiple PostgreSQL database servers

So we are writing an app whose schema should reference data which lies currently in an external PostgreSQL instance. We are negotiating being able to put our schema within the external database, but ...
5
votes
3answers
5k views

Lookup table for a one-to-many relationship

I have a tickets table with an id that I need to associate to a lookup table where the counterpart of that data is another id that is controlled from an outside source. tickets - id - sutff lookup - ...
8
votes
2answers
15k views

Move postgresql database from one server to another

I have created a (spatial) database at my home which is several gigabytes and I want to move the whole database as it is from one computer my works computer. Nothing fansy, I will create a new ...
2
votes
2answers
568 views

Can I replicate views with Slony?

Can I feed some SQL that creates a view to Slony? I have some SQL that does CREATE OR REPLACE VIEW name_of_view and so on, passes it to slonik_execute_script, and then tries to run slonik_create_set ...
18
votes
3answers
28k views

Automating failover in PostgreSQL 9.1

How does one setup two identical servers for automatic failover in PostgreSQL 9.1. OS Centos 5 PostgreSQL 9.1 compiled from source The postgres user account exists on both machines and has a ...