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Articles about DB-related stuff


I've just come to minor notice: PostgreSQL defaults to executing procedures with current user rights, Oracle - with definer's rights. It was rather interesting.

Let's say we have departments table in Oracle:

HR schema for PostgreSQL

I've spent about an hour trying to find good sample schema for PostgreSQL. One was too big, another - too small, one more had too much attributes in tables... At last I gave up and just translated scripts for HR schema creation from Oracle XE. If someone needs the script for table creation and population, it's here...
I've also shared ER-diagram for this schema.

Postgres Interval intersection

Let's discuss one common task: find maximum count of simultaneous events.
We have one table

One big Oracle ASM adventure

I had very unpleasant experience with RAC and ASM. I'd like to share it.

Yesterday after VMware ESX Server upgrade (and maybe unsuccessfull live motion operations on one of two RAC nodes) I had the following records in asm instance alert log:

One small MERGE experiment

We have one task in PostgreSQL: a traffic information gotten from monitoring program should be merged in basic table...  We have current table for one day traffic, and we need to unite it with old data. We could use materialized view, but data from current table must be deleted in the end of day, so the decision with MERGE statement would be better. Unfortunately, PostgreSQL doesn't have MERGE operator, so data will be processed on client's side (programmer didn't want to use pgPL/SQL or suggested in  PostgreSQL manual awful code with savepoints).

Work with blobs in Oracle

I'd like to summarize my very small experience about Oracle blobs. This article contains description of reading and writing files from/to Oracle database. First of all, we use the following table: basic_lob_table (x varchar2 (30), b blob, c clob). I took it from Oracle documentation (Oracle® Database Application Developer's Guide - Large Objects). Let's write java program to load data to the table and select it back. During work we use the following connect method:

Oracle 10 XE installation on FreeBSD 6.2

I've found recently my one year old article. Maybe it'll be usefull.

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