Daniel Westermann

Indexing for like/similarity operations

Indexing queries for like/similarity conditions is not that easy with the usual index types. The only option you have with btree indexes (especially if the wild-card is at the beginning of the filter) is to create a partial(…)

Quickly create a hundred databases and users

Do you need a hundred databases and users for training etc. in PostgreSQL? Just a few lines of code: [postgres8@oel7 data]$ cat create_databases.sh #!/bin/bash NUMOFDBS=100 for i in `seq ${NUMOFDBS}`; do psql -q -c "create user u${i}(…)

another way to list invalid objects

How often did I type a query like this to list the invalid objects in a database? select count(*) from dba_objects where status 'VALID'; -- and user in/not in Today I learned another way to do the same. There(…)

When a function returns a collection: can you directly reference the index of the returned collection?

As I am still interested in PLSQL I browsed the documentation some days ago and learned something new which is about functions returning collections. Here is a simple test case: Let’s create a simple package,(…)

ODA workshop at Arrow ECS

On the 16th and 17th of June David Hueber, Georges Grey and myself had the chance to attend the ODA hands on workshop at Arrow ECS. Lead Trainer Ruggero Citton (Oracle ODA Product Development) did the first day(…)

What is more efficient: arrays or single columns values? – oracle

In the last post on this topic it turned out that using an array as a column type needs more space than using a column per value in PostgreSQL. Now I’ll do the same test case in Oracle.

What is more efficient: arrays or single column values?

In PostgreSQL ( as well as in other rdbms ) you can define columns as arrays. What I wondered is: What is more efficient when it comes to space: Creating several columns or just creating once column as array? The(…)

SQL Interpolation with psql

The PostgreSQL psql utility provides some really nice features. One of these features is SQL interpolation which allows us to do interesting things, e.g. reading files and analyze the results directly in the database. This post(…)

A free PostgreSQL cloud database?

Recently I was looking for a free PostgreSQL cloud database service for testing. Why? Because I’d like to use such a cloud instance for testing no matter on which workstation or OS I am currently on. Another reason is, that(…)

PostgreSQL portable?

What a surprise: Headed over to the sourceforge page, downloaded, installed (which is just a matter of next/next/next) : Not really the latest patchset but far more than I(…)