postgresql

Copying data from STDOUT to a remote machine using SFTP

In order to backup large database partitions to a remote machine using SFTP, I'd like to use the databases dump command and send it directly over using SFTP to a remote location. This is useful when needing to dump large data sets when you don't have enough local disk space to create the backup file, and then copy it to a remote locatio...

Copying an entire table with Postgres

Hello, I'm trying to copy the contents of one table into another in Postgres, however it appears some rows aren't being copied correctly: ActiveRecord::StatementInvalid: PGError: ERROR: column "email_date" is of type timestamp without time zone but expression is of type character varying HINT: You will need to rewrite or c...

Psycopg2 doesn't like table names that start with a lower case letter

I am running ActiveState's ActivePython 2.6.5.12 and PostgreSQL 9.0 Beta 1 under Windows XP. If I create a table with an upper case first letter (i.e. Books), psycopg2 returns the "Programming Error: relation "books" does not exist" error message when I run the select statement: execute("SELECT * FROM Books"). The same error is returned...

npgsql Leaking Postgres DB Connections: Way to monitor connections?

Background: I'm moving my application from npgsql v1 to npgsql v2.0.9. After a few minutes of running my application, I get a System.Exception: Timeout while getting a connection from the pool. The web claims that this is due to leaking connections (opening a db connection, but not properly closing them). So I'm trying to diagnose lea...

Stored Procedure in postgresql, multiple queries w/ agreggates.

I'm trying to write a store procedure that can take some input parameters (obviously), run multiple queries against those, taking the output from those and doing calculations, and from those calculations and the original queries, outputting a formatted text string like: Number of Rows for max(Z) matching condition x and y of total rows ...

Restarting postgres DB servers in a master-slave setup

Is there any documentation on gracefully restarting servers that have PITR implemented. We have a master-slave setup. I want to make sure servers are rebooted in the correct order so as not to mess up WAL shipping. Should i disable WAL shipping prior to server restart? ...

How to convert a PGresult to custom data type with libpq (PostgreSQL)

Hi everyone! I'm using the libpq library in C to accessing my PostgreSQL database. So, when I do res = PQexec(conn, "SELECT point FROM test_point3d"); I don't know how to convert the PGresult I got to my custom data type. I know I can use the PQgetValue function, but again I don't know how to convert the returning string to my custom ...

How do I change the effective user of psql?

I'm using psql to run a simple set of COPY statements contained in a file: psql -d mydb -f 'wbf_queries.data.sql' where wbf_queries.data.sql contains lines: copy <my_query> to '/home/gvkv/mydata' delimiter ',' null ''; ... but I get a permission denied error: ... ERROR: could not open file ... for writing: Permission denied I'm ...

Creating a multi-tenant application using PostgreSQL's schemas and Rails

Stuff I've already figured out I'm learning how to create a multi-tenant application in Rails that serves data from different schemas based on what domain or subdomain is used to view the application. I already have a few concerns answered: How can you get subdomain-fu to work with domains as well? Here's someone that asked the same ...

Why is one query consistently ~25ms faster than another in postgres?

A friend wrote a query with the following condition: AND ( SELECT count(1) FROM users_alerts_status uas WHERE uas.alert_id = context_alert.alert_id AND uas.user_id = 18309 AND uas.status = 'read' ) = 0 Seeing this, I suggested we change it to: AND NOT EXISTS ( SELECT 1 FROM users_alerts_statu...

g++ problem with -l option and PostgreSQL

Hi I've written simple program. Here a code: #include <iostream> #include <stdio.h> #include <D:\Program Files\PostgreSQL\8.4\include\libpq-fe.h> #include <string> using namespace std; int main() { PGconn *conn; PGresult *res; int rec_count; int row; int col; cout << ...

Postgres 8.3: "ERROR: cached plan must not change result type"

This exception is being thrown by the PostgreSQL 8.3.7 server to my application. Does anyone know what this error means and what I can do about it? ERROR: cached plan must not change result type STATEMENT: select code,is_deprecated from country where code=$1 ...

Seam/Hibernate and PostgreSQL -- Any issues?

I'm currently working on a project that makes use of Seam/Hibernate (JPA) on MySQL. I'm reconsidering moving towards PostgreSQL after investigating some of the features that it provides. My question is, is there anything I need to worry about with this configuration? Limitations? Gotchas? Things to watch out for? There will be some...

Excel and pgSQL

How do I import data from a excel sheet onto a PGSQL database on linux? ...

rake test and test_structure.sql

First of all, I have to run "rake RAILS_ENV=test ..." to get the test suites to hit my test DB. Annoying but ok to live with. However when I do so, I get a long stream of errors like so: > rake RAILS_ENV=test -I test test:units psql:/path/to/project/db/test_structure.sql:33: ERROR: function "armor" already exists with same argument ty...

Best indexing strategy for several varchar columns in Postgres

I have a table with 10 columns that need to be searchable (the table itself has about 20 columns). So the user will enter query criteria for at least one of the columns but possibly all ten. All non-empty criteria is then put into an AND condition Suppose the user provided non-empty criteria for column1 and column4 and column8 the query...

fastest way to upload an xls file into a database

I have an xls file with ~60 sheets of data. I would like to move them into a database (postgres) such that each sheet's data is stored in a different table. What is the fastest way of creating these tables? I don't care about naming or proper typing of columns. The columns could all be strings for that matter. I don't want to run 60 dif...

Hibernate Native Query problem with named parameters

I have a problem with Hibernate Native Query. I have one SELECT that selects array slice (PostgreSQL database). The problem is that hibernate recognizes the following part: ":300" from "SELECT my_array[1:300]..." as named parameter and I get the following exception: Not all named parameters have been set. I tried to escape the colon (:...

Calculate differences between rows while grouping with SQL

I have a postgresql table containing movements of different items (models) between warehouses. For example, the following record means that 5 units of model 1 have been sent form warehouse 1 to 2: source target model units ------ ------ ----- ----- 1 2 1 5 I am trying to build a SQL query to obtain the difference be...

Ruby on rails active-record generated SQL on Postgres

Dear all, Why does Ruby on rails generated more queries in the background on Postgres than MySQL? I haven't tried deploying Rails on production with Postgres yet, but I am just afraid this generated queries would affect the performance. Do you find Rails with Postgres is slower than MySQL, knowing that it produce more query on the backg...