postgresql

Sorting tree with a materialized path?

I have a tree structure in a table and it uses materialized paths to allow me to find children quickly. However, I also need to sort the results depth-first, as one would expect with threaded forum replies. id | parent_id | matpath | created ----+-----------+---------+---------------------------- 2 | 1 | 1...

Multi-variable indexes in postgres

Im looking at an application where I will be doing quite a few SELECTs where I am trying to find column_a = x AND column_b = y. Is the correct to create that index that something like the following? CREATE INDEX index_name ON table (column_a, column_b) ...

how to restore postgresql DB without backup

Forgot to make a backup. Now I have harddrive with databases and new system with empty postgres. Can I somehow restore databases? by simple copy of files etc? ...

Remove redundant SQL code

Code The following code calculates the slope and intercept for a linear regression against a slathering of data. It then applies the equation y = mx + b against the same result set to calculate the value of the regression line for each row. How can the two queries be joined so that the data and its slope/intercept are calculated withou...

table design for storing large number of rows

I am trying to store in a postgresql database some unique identifiers along with the site they have been seen on. I can't really decide which of the following 3 option to choose in order to be faster and easy maintainable. The table would have to provide the following information: the unique identifier which unfortunately it's text the...

Transfering data from one database to another (Postgres)

I have 2 exactly same databases on 2 different machines(with different data that is), and I want to transfer contents of one table to the table from the other database, how do I do that from PgAdmin? I'm new to PostgreSQL Database, I'd do that easily with mysql phpmyadmin just export sql and I'd get text file with bunch of insert into st...

Mapping a boolean[] PostgreSql column with Hibernate

I have a column in a PostgreSql database that is defined with type boolean[]. I wish to map this to a Java entity property using Hibernate 3.3.x. However, I cannot find a suitable Java type that Hibernate is happy to map to. I thought that the java.lang.Boolean[] would be the obvious choice, but Hibernate complains: Caused by: org.hiber...

Sql Querying, group relationships

Hi, Suppose I have two tables: Group ( id integer primary key, someData1 text, someData2 text ) GroupMember ( id integer primary key, group_id foreign key to Group.id, someData text ) I'm aware that my SQL syntax is not correct :) Hopefully is clear enough. My problem is this: I want to load a group record...

Encoding error PostgreSQL 8.4

I am importing data from a CSV file. One of the fields has an accent(Telefónica O2 UK Limited). The application throws en error while inserting the data to the table. PGError: ERROR: invalid byte sequence for encoding "UTF8": 0xf36e6963 HINT: This error can also happen if the byte sequence does not match the encoding expected by the ...

importing csv file into pgsql

ok im trying to upload this csv file onto my table in pgsql but im getting this error ERROR: invalid input syntax for integer: "mlname,mfname,slname,sfname,address,postalcode,membershiptype,hphone,email" CONTEXT: COPY members2, line 1, column id: "mlname,mfname,slname,sfname,address,postalcode,membershiptype,hphone,email" i really...

Good Postgres graphical client for Windows

The name pretty much says it all. Right now I'm using Squirrel - it crashes frequently and suffers from memory problems (I've tried increasing the heap size). I don't need anything particularly fancy or full-featured - just something that won't take up 2.4 GB of RAM to store a 1.5 million line, 8 column result set. ...

Postgresql - one database for everyone, or one-database per customer

I'm working on a web-based business application where each customer will need to have their own data (think basecamphq.com type model) For scalability and ease-of-upgrades, I'd prefer to have a single database where each customer gets a filtered version of the data. The problem is how to guarantee that they stay sandboxed to their own ...

Future proof Primary Key design in postgresql

I've always used either auto_generated or Sequences in the past for my primary keys. With the current system I'm working on there is the possibility of having to eventually partition the data which has never been a requirement in the past. Knowing that I may need to partition the data in the future, is there any advantage of using UUID...

PostGreSQL - bind variables and date addition

I need to update some timestamp columns in a table in a PostGres (8.3) database. My query (simplified) look like this: update table1 set dateA = dateA + interval '10 hours' where id = 1234; This is part of a script and there's a lot to update so my preference is to use bind variables, rather than to have to build the query string eac...

How to rewrite long query?

Hi, I have the following 2 tables: items: id int primary key bla text events: id_items int num int when timestamp without time zone ble text composite primary key: id_items, num and want to select to each item the most recent event (the newest 'when'). I wrote an request, but I don't know if it could be written more efficient...

General many-to-many relationship problem ( Postgresql )

Hi, i have two tables: CREATE TABLE "public"."auctions" ( "id" VARCHAR(255) NOT NULL, "auction_value_key" VARCHAR(255) NOT NULL, "ctime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, "mtime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, CONSTRAINT "pk_XXXX2" PRIMARY KEY("id"), ); and CREATE TABLE "public"."auction_values" ( "id" NUMERIC DEFAU...

Postgresql - Edit function signature

POSTGRESQL 8.4.3 - i created a function with this signature CREATE OR REPLACE FUNCTION logcountforlasthour() RETURNS SETOF record AS realised i wanted to change it to this CREATE OR REPLACE FUNCTION logcountforlasthour() RETURNS TABLE(ip bigint, count bigint) record AS but when i apply that change in the query tool it isnt accept...

Using the MySql ASP.NET membership provider with existing users

I have been tasked with migrating an existing mature ASP.NET 2.0 web site to NHibernate, Mono and MySQL or postgres. I am somewhat confused as how the membership provider salts the passwords. If I make the switch and use the MySQL membership provider (outlined in this question) or AspSqlProvider, will the existing users be able to logi...

Postgres: Convert varchar to text

I screwed up and created a column as a varchar(255) where that is no longer sufficient. I've read that varchar has no performance benefits over text on Postgres, and so would like to convert the varchar to a text column in a safe way that preserves the data. What's the best way for me to do this? ...

What is postgresql_psycopg2 ?

What is postgresql_psycopg2 ? Difference from postgresql ? ...