Re: [SQL] iceberg queries

2003-02-04 Thread Christoph Haller
Does PostgreSQL optimizer handle iceberg queries well? What do you mean by iceberg query ? I've never heard this term. Regards, Christoph ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]

Re: [SQL] pg_views

2003-02-04 Thread Christoph Haller
I'm wondering if PostgreSQL actually reparses the view definition on each invocation or if it stores the required information in some accessible place. The documentation says: Whenever a query against a view (i.e. a virtual table) is made, the rewrite system rewrites the user's query to

Re: [SQL] SQL99/SQL92 Grammar

2003-02-04 Thread Bruce Momjian
See the developers FAQ for URL's. --- Les Hazlewood wrote: Does anyone have a definitive BNF grammar of SQL99 or SQL92? (I'd prefer 99 but I'll take what I can get ;) I'm trying to make a simplified XML to SQL

Re: [SQL] iceberg queries

2003-02-04 Thread Wei Weng
It is a query that looks like SELECT target1, target2... targetn, SUN(t.qty) FROM Table t GROUP BY target1 HAVING SUM(t.qty)=10 You can replace SUM(t.qty)=10 with other aggregate constraints. - Original Message - From: Christoph Haller To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]

Re: [SQL] iceberg queries

2003-02-04 Thread Bruno Wolff III
On Tue, Feb 04, 2003 at 09:08:56 -0500, Wei Weng [EMAIL PROTECTED] wrote: It is a query that looks like SELECT target1, target2... targetn, SUN(t.qty) FROM Table t GROUP BY target1 HAVING SUM(t.qty)=10 You can replace SUM(t.qty)=10 with other aggregate constraints. There were some

Re: [SQL] pg_views

2003-02-04 Thread Jan Wieck
Lex Berezhny wrote: hi, I'm trying to write some code that can analyze the database structure and i need a way to discover the composition of a view (the tables and table.column info). I've managed to do much of this by querying the pg_views for the definition and literally parsing

Re: [SQL] iceberg queries

2003-02-04 Thread Jan Wieck
Christoph Haller wrote: Does PostgreSQL optimizer handle iceberg queries well? What do you mean by iceberg query ? I've never heard this term. Iceberg queries compute one or more aggregate functions to find aggregate values above a specified threshold. A typical iceberg query would be

Re: [SQL] iceberg queries

2003-02-04 Thread Tom Lane
Jan Wieck [EMAIL PROTECTED] writes: As to the original question, if an index is available that returns the rows in the sort order of the GROUP BY clause, PostgreSQL defaults to an index scan, otherwise it will do a sort of the rows matching an optional WHERE clause. This sorted set is then

Re: [SQL] pg_views

2003-02-04 Thread Tom Lane
Jan Wieck [EMAIL PROTECTED] writes: Lex Berezhny wrote: My goal is to take a view name as input and output the tables and columns composing the view. Don't forget that a view's columns can contain complex expressions instead of simple table.column references. Yes. This problem is not

[SQL] Serialized Transaction Locking Issues

2003-02-04 Thread justin
Hello, I'm currently in the midst of working on a serializable transaction which drops indexes on several tables, does a bulk copy, and rebuilds the indexes. Based on what I've read it seemed as though I'd be able to concurrently execute read only queries against these tables, returning

Re: [SQL] iceberg queries

2003-02-04 Thread Jan Wieck
Tom Lane wrote: Jan Wieck [EMAIL PROTECTED] writes: As to the original question, if an index is available that returns the rows in the sort order of the GROUP BY clause, PostgreSQL defaults to an index scan, otherwise it will do a sort of the rows matching an optional WHERE clause. This

Re: [SQL] Serialized Transaction Locking Issues

2003-02-04 Thread Tom Lane
justin [EMAIL PROTECTED] writes: I'm currently in the midst of working on a serializable transaction which drops indexes on several tables, does a bulk copy, and rebuilds the indexes. Based on what I've read it seemed as though I'd be able to concurrently execute read only queries against

[SQL] Inserting a tab character

2003-02-04 Thread Luke Pascoe
I have a table which defines various possible file delimiters (CHAR(1) NOT NULL), for the moment it'll only contain comma and tab. Inserting a comma is easy, but inserting a tab is proving somewhat more difficult. How do I do it in 'psql'? Luke Pascoe. ---(end of

Re: [SQL] Inserting a tab character

2003-02-04 Thread Matthew Horoschun
Hi Luke. On Wednesday, February 5, 2003, at 02:39 PM, Luke Pascoe wrote: I have a table which defines various possible file delimiters (CHAR(1) NOT NULL), for the moment it'll only contain comma and tab. Inserting a comma is easy, but inserting a tab is proving somewhat more difficult. How

Re: [SQL] Inserting a tab character

2003-02-04 Thread Ludwig Lim
--- Luke Pascoe [EMAIL PROTECTED] wrote: I have a table which defines various possible file delimiters (CHAR(1) NOT NULL), for the moment it'll only contain comma and tab. Inserting a comma is easy, but inserting a tab is proving somewhat more difficult. How do I do it in 'psql'? --