Simon Krenger

Ok, so here is a problem that a developer brought up. I thought that this problem is quite interesting and also a bit confusing. Obviously, according to Oracle, this is not a bug – it’s a feature!

When issuing a CREATE MATERIALIZED VIEW statement for a different schema (as DBA), one might encounter the following error:

dba@KDB01:SQL> CREATE MATERIALIZED VIEW simon.simon_mv AS SELECT * FROM dual;
CREATE MATERIALIZED VIEW simon.simon_mv AS SELECT * FROM dual
                                                         *
ERROR at line 1:
ORA-01031: insufficient privileges

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Whenever one has to move large amounts of data from one database to another, storage space might become an issue. An option to circumvent this problem is to use a database link with Oracle Datapump to move the data from one database to another. This way, the data is exported across the network and imported directly into the target database.

In this post, I will provide an example on how to move data via a Oracle Datapump and a database link. This post is based on the excellent entry in Oracle FAQ and basically comments all the steps mentioned in the article.

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So here is another post I keep for my own reference, since I keep forgetting about precision and scale, primarily which is which.

The Oracle Concepts guide states that the NUMBER datatype stores fixed and floating-point numbers. A column with the NUMBER datatype can be defined as follows:

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So this happens when you try to add a privilege to an ACL that does not exist:
SQL> EXEC DBMS_NETWORK_ACL_ADMIN.ADD_PRIVILEGE ('myacl.xml', 'SIMON', true, 'connect');
BEGIN DBMS_NETWORK_ACL_ADMIN.ADD_PRIVILEGE ('myacl.xml', 'SIMON', true, 'connect'); END;

ERROR at line 1:
ORA-31001: Invalid resource handle or path name "/sys/acls/myacl.xml"
ORA-06512: at "SYS.DBMS_NETWORK_ACL_ADMIN", line 384
ORA-06512: at line 1
Oracle Database 11g introduced fine-grained access control to external network services using Access Control Lists (ACLs). This basically allows you to take control over which users access which network resources, regardless of package grants. Read the rest of this entry »

There is always something that gets in the way. One problem I regularly stumble upon when installing a new Oracle 11g R2 installation is the following error when I try to start the database:

SQL> startup nomount;
ORA-00845: MEMORY_TARGET not supported on this system

So I keep this post mainly for my own reference when installing a new database on a Linux system.

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In this article, I will describe the steps necessary to install Oracle SQL*Plus on a Debian host. I am using Debian 6.0.5 and will install the “Instant Client” package from Oracle (version 11.2.0.3). First, we will prepare the system for the installation, download the installation package, set all the necessary variables, start SQL*Plus and connect to an instance. So let’s get started…

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Since most of our databases are not licensed with the Oracle Enterprise Manager Diagnostic Pack, we cannot use AWR (Automatic Workload Repository) and ADDM (Automatic Database Diagnostic Monitor). So we have to use the good old Oracle STATSPACK.

The goal of this article is to provide a quick reference for installing and maintaining STATSPACK for an Oracle database. It is based on the excellent “STATSPACK Survival Guide” of Akadia AG. If you need more information on STATSPACK, please refer to the Survival Guide or the Oracle documentation, since this article is only a really quick summary on how to install, configure and use STATSPACK. Read the rest of this entry »

When setting up a new server in a highly secured network, one does not always have access to the Red Hat Network to download packages for the installation of the server. Often, a local repository is provided later on in the setup process.

This leaves us with the problem of installing the necessary packages for the Oracle database. Luckily, we can use the DVD we used for the installation of the Operating System to get all required packages.

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One thing DBAs regularly do is to gather information on the schemas in the database for reporting. So we want to know how many rows there are in the tables of the schema “SIMON”. When doing so, one is tempted to query the DBA_TABLES view:

SQL> SELECT table_name, tablespace_name, num_rows
  2  FROM dba_tables WHERE owner='SIMON' ORDER BY num_rows DESC;

TABLE_NAME                     TABLESPACE_NAME                  NUM_ROWS
------------------------------ ------------------------------ ----------
HUGE_TABLE                     DZ_DATA01                         8227990
[..]

However, if we query the table directly, we get a different result:
SQL> SELECT count(*) FROM simon.HUGE_TABLE;
COUNT(*)
----------
8230310

Why is that so? Read the rest of this entry »

When deploying a new database, one thing I usually do is to set up a logrotate configuration for the Oracle Listener log. The Oracle Listener logs every connection he makes and when using an Application Server to interface the database, this file can grow quite a bit. So we need to make sure that we properly rotate this log and compress the old logs.

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