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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4
votes
2answers
849 views

Creating a GroupBy query to include a result for when no results match

Let's say I need a query to see sales results by Month and I want the result-set to include results for each month whether there were any sales in that month or not. And let's say my table "sales" ...
2
votes
2answers
368 views

What does “GIN doesn't support full index scans” mean?

I'm a RDBMS newbie and I have a PostgreSQL database of more than 50 millions lines, growing everyday. There is a column 'text', which contains human-generated text of around 20 words. I need to be ...
2
votes
2answers
358 views

Database Transfer from PostgreSQL to MySQL

Is there any method to tranfer the data and schema from a postgresql database to mysql?
3
votes
1answer
4k views

How can I generate scripts for all functions in pgAdmin?

I am using pgAdmin version 1.10.5, and I've checked the properties and menu options but couldn't find anything on the subject. For example, I just want to generate a script that includes the ...
1
vote
2answers
1k views

Is the mapping between PostgreSQL system tables and information_schema views documented?

If you connect pgadminIII to a PostgreSQL 9.x server, you'll find two catalogs exposed in the user interface: ANSI (information schema), and PostgreSQL (pg_catalog). I'm looking for documentation ...
2
votes
1answer
616 views

What are all the reasons/possibilities that may fail to release disk space occupied by TEMPORARY table?

We're using PostgreSQL v8.2.3. Ours is a web-based application and we're using pgpool-II v 2.0.1 purely for connection pooling (we don't use other features of pgpool like Replication, Load Balancing, ...
4
votes
2answers
8k views

Postgres plpgsql - Using a variable inside of a dynamic create statement

Using Postgres pl/pgsql, I'm attempting to create a table using a dynamic EXECUTE command, such as: ... DECLARE tblVar varchar := "myTable"; BEGIN EXECUTE 'CREATE TABLE $1 ( foo ...
3
votes
1answer
5k views

PostgreSQL: Change log file location

How can I change the location of the log file in PostgreSQL? Can it be done without stopping the cluster?
1
vote
2answers
221 views

Postgresql Cost-Based Vacuum Delay parameters

How to set the these parameters on postgresql.conf ? What I should consider while setting them? What should I monitor? #vacuum_cost_delay = 0ms #vacuum_cost_page_hit = 1 ...
2
votes
1answer
503 views

What are the pro's and con's of using PostgreSQL vs MySQL for binary data?

I read that MySQL has binary safe blobs, but PostgreSQL does not. So far what I've found suggests that "binary safe" is something that really relates to functions and handling of data, not the data ...
7
votes
3answers
3k views

Is there a way to access temporary tables of other sessions in postgres?

I'm working with a Windows application that uses a (local) postgres Database and stores some information in a temporary table. I'd like to have a look at the temporary table, but pgadmin and dbVis ...
5
votes
2answers
1k views

PostgreSQL: Last access time to table

I am in charge of a large PostgreSQL database, with few dozen tables. I suspect that many of these tables are never accessed. What's the best way to check when was the last time a certain table was ...
6
votes
4answers
2k views

Determine when a PostgreSQL database was last changed

I'm looking at altering how backups are done and am wondering if there is a way to determine which databases in a postgreql cluster have not been recently changed? Instead of using pg_dumpall, I'd ...
1
vote
3answers
203 views

PostgreSQL: 8.3/8.4 interface chages?

I would like to upgrade a PostgreSQL 8.3 server to PostrgreSQL 8.4. There are many software components that interact with the server over the network, and I am concerned with compatibility issues. Is ...
8
votes
3answers
17k views

How to solve UTF8 invalid byte sequence copy errors on a restore, when the source database is encoded in UTF8?

I was given the task to migrate a PostgreSQL 8.2.x database to another server. To do this I'm using the pgAdmin 1.12.2 (on Ubuntu 11.04 by the way) and using the Backup and Restore using the ...
4
votes
1answer
1k views

PostgreSQL: Corrupt primary key, inconsistent table

While recovering from a cloud failure, I found that some tables on a PostgreSQL database are behaving strangely. These tables are indexed using a primary key, but a pg_dump yielded duplicate fields, ...
3
votes
2answers
2k views

PostgreSQL: Using schema and table names from other tables?

Consider the situation where I have all my schema names in one table and all my table names in another table. Is it possible to do something like in the following? SELECT value FROM (SELECT ...
2
votes
2answers
134 views

Get a count of shippable orders

I have two tables: orders and order_lines. I need a fast, inexpensive way to display a count for orders that are going to be shipping today. The order_lines table is associated with the orders table ...
9
votes
2answers
4k views

How do I create an index to speed up an aggregate LIKE query on an expression in postgres 8.4?

I may be asking the wrong question in the title. Here are the facts: My customer service folk have been complaining about slow response times when doing customer lookups on the administration ...
4
votes
2answers
1k views

Estimate average and median efficiently in Postgres?

I have a Postgres database with tables in the billion scale. So any aggregate functions such as count() and avg(), as well as "order by random()" are very time consuming. Postgres has pg_catalog which ...
2
votes
2answers
619 views

PostgreSQL: Separate tables vs single table to perserve disk space?

I have 2 tables with the below schemas with equal number of rows. When I run the SELECT relname, relpages FROM pg_class ORDER BY relpages DESC command, they show up as 23GB each even though the data ...
7
votes
2answers
19k views

List the database privileges using psql

I'm in the middle of a database server migration and I can't figure (after googling and searching here) how can I list the database privileges (or all the privileges across the server) on PostgreSQL ...
4
votes
2answers
645 views

Index Generation in Postgres

We have a database with a single table made up of around 700 million entries. We update the database by adding new entries on a server then transfer the server to the production server using pg_dump: ...
4
votes
1answer
573 views

Is the PostgreSQL 'connection limit' shared across all users in a role?

I have created a role that many users can share: > create role foo_read_only connection limit 5; I have then assigned permissions to that role: > grant select on table1 to foo_read_only; ...
3
votes
3answers
584 views

ts_rank massively slows my query, how can I improve performance?

Here's the table definition Table "public.kb_article_contents" Column | Type | Modifiers ------------+----------+----------- article_id | smallint | not null contents | text | not ...
3
votes
1answer
7k views

psql denies access to file when using COPY FROM

When I do this: COPY "mytable" FROM '/my/file.csv' WITH DELIMITER AS ',' CSV; On this: -rw-r--r-- 1 peter peter 54819176 2011-07-21 13:17 file.csv psql tells me this: ERROR: could not open ...
2
votes
3answers
961 views

MySQL and PostgreSQL Licence issue

Our Company wants to use MySQL for one software product. This product is not open-source. Is it legal to use it freely ? If not, how about PostgreSQL ? Is this okay for our purpose ?
4
votes
1answer
595 views

PostgreSQL exit status when running a file

When running PostgreSQL with a single SQL command error codes are returned as expected: % psql -c "SELECT * FROM AWDASDASDASDAS" my_db ERROR: relation "awdasdasdasdas" does not exist LINE 1: SELECT ...
9
votes
1answer
4k views

How to migrate large blob table from mysql to postgresql?

I'm now in process of migrating my MySQL database to PostgreSQL. Almost everything went fine (well, after lots of googling for correct mysqldump params etc.) except one table I have - actually the ...
2
votes
2answers
124 views

Database Agnostic Conditional

I'm writing a Drupal module and I want it to be agnostic between PostgreSQL and MySQL. I have a field that gets its value from a conditional, and I originally wrote it as an IF(). Then I found out ...
2
votes
2answers
6k views

Which business intelligence tool is better for use with a PostgreSQL database?

I'm trying to find a good BI tool which can be connected to a PostgreSQL database. I need the following abilities: Reporting Services Dashboards OLAP Data Mining. The BI server should work on ...
11
votes
1answer
1k views

How does PostgreSQL handle Checkpoints in the middle of a WAL-enabled backup?

On a PostgreSQL v9.0 I've a WAL archiving system working. So WAL files a regulary archived (when 3 WAL are created or if a WAL is older than 15 minutes). Now I add a binary packup of the PG_DATA ...
1
vote
1answer
14k views

How can I convert a string to a double precision in PostgreSQL?

How can I convert a string to a double precision in PostgreSQL ? I tried something like : update points set latitude2 = cast(latitude as double) ; where latitude is a string and latitude2 is a ...
10
votes
3answers
3k views

How should I represent a latitude and longitude in Postgres without using PostGIS?

How should I represent a latitude and longitude in Postgres without using PostGIS? The system I am using does not allow SQL passthrough so I cannot use POSTGIS.
2
votes
2answers
786 views

Effective backup and archive strategy for database and linked files

I am using Postgres to store a variety of application data for a webapp. Part of the application involves storing and retrieving user uploaded files. I am storing the files in the filesystem with ...
5
votes
3answers
2k views

Postgresql row-level encryption

Looking over the docs, I didn't see any mention of row-level encryption. Lets assume I have a database of highly classified information that needs to get locked down. How can I implement a table with ...
4
votes
3answers
2k views

Optimizing query using view on EAV structure

An application is writing into a database that follows an EAV structure, similar to this: CREATE TABLE item ( id INTEGER PRIMARY KEY, description TEXT ); CREATE TABLE item_attr ( item ...
7
votes
1answer
1k views

PostgreSQL: Disk space not released after TRUNCATE

I haveTRUNCATEd a huge (~120Gb) table called files: TRUNCATE files; VACUUM FULL files; The table size is 0, but no disk space was released. Any ideas how to reclaim my lost disk space? UPDATE: The ...
3
votes
1answer
10k views

How can I convert from Double Precision to Bigint with PostgreSQL?

I need to convert a value of Double Precision to Bigint with PostgreSQL. How can I do that? I have tried with to_bigint(myvalue) but that function didn't exist.
21
votes
3answers
3k views

Is it possible to quickly create/restore database snapshots with PostgreSQL?

First of all, I'm a developer, not a DBA or sysadmin; please be gentle :) I'm working on an application workflow where a single user action will trigger complex changes in the database - creating ...
2
votes
1answer
640 views

Pgpool-II: sequences advanced by 1 after PITR recovery

I have tested pgpool-II 3.0.1 and pgpool 3.0.4, PostgreSQL 8.4 In both cases I'm getting the same result: after online recovery on primary and target nodes all 'serial' values got "+1". Other nodes ...
3
votes
1answer
2k views

How to list all postgres tables in one particular schema

Using the psql command line tool, how do I list all postgres tables in one particular schema
2
votes
2answers
497 views

Degrading PostgreSQL 8.4 write performance

Load testing of postgresql 8.4 for OLTP application suitability resulted in unpleasant situation when throughput of the database significantly degraded over time from thousands of write transactions ...
4
votes
1answer
988 views

PostgreSQL on Ubuntu - Using conf files for recovery

I am using PostgreSQL 8.4 on Ubuntu LTS 10.04.02 server version. I use pg_standby to restore the data and for database recovery created a recovery.conf and placed it on /etc/postgresql/8.4/main where ...
2
votes
2answers
3k views

Postgresql - Recovery using recovery.conf

I am trying to recover a database using recovery.conf file for making point-in-time copy. On recovery.conf file, I added a recovery target time as below. recovery_target_time = '2011-06-16 04:10:00 ...
3
votes
2answers
1k views

Removing Archive Logs after PostgreSQL PITR online-recovery

I'm using pgpool-II + PostgreSQL 8.4 on three servers: primary + standby1 + standby2. Replication mode is "on" Load balance mode is "on" (between primary and standby1) I followed the official ...
4
votes
1answer
972 views

Source several files at once with psql

I want to execute several sql scripts sequentially with psql as a single transaction to set up my database schema. What is the best way to do this? In the past I know I had a master script that I ran ...
2
votes
1answer
2k views

How do I install pgcrypto on Windows?

I would like to install pgcrypto in Windows. I have a file C:\Program\PostgreSQL\9.0\share\contrib\pgcrypto.sql but when I try to run it in psql I get an error: C:: Permission denied How do I solve ...
18
votes
2answers
27k views

How do I use currval() in PostgreSQL to get the last inserted id?

I have a table: CREATE TABLE names (id serial, name varchar(20)) I want the "last inserted id" from that table, without using RETURNING id on insert. There seem to be a function CURRVAL(), but I ...
4
votes
2answers
5k views

How can I specify the position for a new column in PostgreSQL?

If I have a table with the columns: id | name | created_date and would like to add a column, I use: alter table my_table add column email varchar(255) Then the column is added after the ...