postgresql

Check value at insert

Hello, i have this three tables. Table: Item Columns: ItemID, Title, Content, NoChange (Date) Table: Tag Columns: TagID, Title Table: ItemTag Columns: ItemID, TagID In the Item Table is a Field with NoChange, if this field = true no Tag is allowed to insert a ItemTag value with this ItemID. How can i check this in the insert? For U...

Prepared transactions with Postgres 8.4.3 on CentOS

I have set 'max_prepared_transactions' to 20 in the local postgres.config and yet the transaction fails with the following error trace (but only on Linux). Since in Windows the same code works seamlessly I am wandering if this isn't an issue of permission. What would be the solution? Thanks Peter 372300 [Atomikos:7] WARN atomikos - XA ...

Where can I download Northwind database for Postgresql?

Is there a downloadable Postgres database that contains dummy data? preferably Northwind, something i can practice my query ideas ...

consistency of Trigger Procedure (before row trigger) Postgresql

Using Postgresql. I try to use TRIGGER procedure to make some consistency check on INSERT. The question is ...... whether "BEFORE INSERT FOR EACH ROW" can make sure each row to insert "checked" and "inserted" one after another? do I need extra lock on table to survive from concurrent insert? check for new row1 -> insert row1 -> check...

what is the difference

I'm not even sure what this is called? But I'm trying to learn what the difference is between writing a function like this is in plpgsql: CREATE OR REPLACE FUNCTION foo() RETURNS TRIGGER AS $$ .... $$ LANGUAGE plpgsql; vs CREATE OR REPLACE FUNCTION foo() RETURNS TRIGGER AS $foo$ .... $foo$ LANGUAGE plpgsql; is there a diff...

How to convert varchar to date in PostgreSQL?

Hi, I have varchar data type column and date data type column . I have to update varchar column data into date column in PostgreSQL. Is it possible? Thanks. chandu ...

Representing Sparse Data in PostgreSQL

What's the best way to represent a sparse data matrix in PostgreSQL? The two obvious methods I see are: Store data in a single a table with a separate column for every conceivable feature (potentially millions), but with a default value of NULL for unused features. This is conceptually very simple, but I know that with most RDMS implem...

ERROR: there is no parameter $1 when creating view

When we try to create a view within a funcion we get ERROR: there is no parameter $1. This is the sample code. Begin CREATE VIEW artikelnr AS SELECT datum, 'uitgifte' as "type", CASE WHEN 'test'='test' THEN 0 END as "aantal ontvangen", aantal as "aantal uitgegeven" FROM uitgifteregel JOIN artikel ON artikel.artikelnr = new.artikelnr J...

how to generate the "create table" sql statement for an existing table in postgreSQL

I have a table created long ago in postgreSQL. Now i want to look at the sql statement used to create it but cannot figure it out. Also when i do the \dS+ tablename it says table not found, but \dt+ tablename is working fine. The \dS+ lists all the table names owned by the root postgres user and doesn't show up tables that i created wi...

For a set of sql-queries, how do you determine which result-set contains a certain row?

I have a set of sql - queries: List<String> queries = ... queries[0] = "select id from person where ..."; ... queries[8756] = "select id from person where ..."; Each query selects rows from the same table 'person'. The only difference is the where-clause. Table 'person' looks like this: id | name | ... many other columns How can...

How do you find the disk size of a Postgres / PostgreSQL table and its indexes

I'm coming to Postgres from Oracle and looking for a way to find the table and index size in terms of bytes/MB/GB/etc, or even better the size for all tables. In Oracle I had a nasty long query that looked at user_lobs and user_segments to give back an answer. I assume in Postgres there's something I can use in the information_schema t...

How do you find the row count for all your tables in Postgres

I'm looking for a way to find the row count for all my tables in Postgres. I know I can do this one table at a time with a select count(*) from table_name; but I'd like to see the row count for all the tables and the order by that to get an idea of how big all my tables are. ...

Get the last N rows in the database in order?

Let's say I have the following database table: record_id | record_date | record_value -----------+-------------+-------------- 1 | 2010-05-01 | 195.00 2 | 2010-07-01 | 185.00 3 | 2010-09-01 | 175.00 4 | 2010-05-01 | 189.00 5 | 2010-06-01 | 185.00 6...

Copy a domain in old schema to new schema with a procedure in postgresql

How do we copy a domain in old schema to new schema using a procedure in postgresql? ...

Unable to uninstall postgreSQL from Add/Remove Programs

Running Windows XP Pro. Have been successfully using and deploying postgres for 2 years. When I try to Uninstall PostgreSQL 8.3 using Windows Add/Remove Programs I get this message: Service "PostgreSQL Database Server 8.3' (pgsql-8.3) failed to start. Verify that you have sufficient privileges to start system services. I have tried th...

What is the effect on record size of reordering columns in PostgreSQL?

Since Postgres can only add columns at the end of tables, I end up re-ordering by adding new columns at the end of the table, setting them equal to existing columns, and then dropping the original columns. So, what does PostgreSQL do with the memory that's freed by dropped columns? Does it automatically re-use the memory, so a single r...

Counting string length in javascript and Ruby on Rails

I've got a text area on a web site that should be limited in length. I'm allowing users to enter 255 characters, and am enforcing that limit with a Rails validation: validates_length_of :body, :maximum => 255 At the same time, I added a javascript char counter like you see on Twitter, to give feedback to the user on how many characte...

Hibernate schema parameter doesn't work in @SequenceGenerator annotation

I have the following code: @Entity @Table(name = "my_table", schema = "my_schema") @SequenceGenerator(name = "my_table_id_seq", sequenceName = "my_table_id_seq", schema = "my_schema") public class MyClass { @Id @GeneratedValue(generator = "my_table_id_seq", strategy = GenerationType.SEQUE...

ISBNs are used as primary key, now I want to add non-book things to the DB - should I migrate to EAN?

I built an inventory database where ISBN numbers are the primary keys for the items. This worked great for a while as the items were books. Now I want to add non-books. some of the non-books have EANs or ISSNs, some do not. It's in PostgreSQL with django apps for the frontend and JSON api, plus a few supporting python command-line tools...

Rails Resque workers fail with PGError: server closed the connection unexpectedly

I have site running rails application and resque workers running in production mode, on Ubuntu 9.10, Rails 2.3.4, ruby-ee 2010.01, PostgreSQL 8.4.2 Workers constantly raised errors: PGError: server closed the connection unexpectedly. My best guess is that master resque process establishes connection to db (e.g. authlogic does that when...