Simon Krenger

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.

So here is another post I keep mainly for my own reference, since I regularly need to gather new schema statistics. The information here is based on the Oracle documentation for DBMS_STATS, where all the information is available.

So if you want to COMPUTE the statistics (which means to actually consider every row and not just estimate the statistics), use the following syntax:

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:

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.

After installing the Operating System (in my case usually Red Hat Enterprise Linux or Oracle Enterprise Linux) and configuring all necessary parameters, one has to install the Oracle software. It is usually a good idea to use a response file to do this.

There are a few reasons to use a response file:

For Nagios, many, many Oracle plugins are available for checking database availability and performance. But if you just want to check if the instance is up and running (and not add more complexity), you can use the simple script provided here.

In an earlier post, I showed how to install SQL*Plus on Debian and based on that tutorial, I wrote a little shell script to query a database (I called it check_oracle_dual.sh):

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.

This error comes up because you tried to use the Automatic Memory Management (AMM) feature of Oracle 11g R2. Well done, but it seems that your shared memory filesystem (shmfs) is not big enough. So let’s look at the steps necessary to enlarge your shared memory filesystem to avoid the error above.

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…

Before we begin the package installation, we need to make sure the necessary prerequisite packages are installed. Oracle Instant Client requires the libaio package, so let’s install that:

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.

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.