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Capacity trending graphs/charts in Oracle Grid Control

Example trending chart

Below I will annotate an example using SQL to extract and chart some tablespace trending data using GNU Plot.

Oracle's Grid Control collects, stores, and manages historical metric data for hosts, databases, and all sorts of targets. This data is difficult to retrieve, especially the historical data. Creating a report in Grid Control results in a small bitmapped image. If you need, say, a year of CPU data, this small bitmap is difficult to interpret.

If the data is extracted from Grid Control's Oracle Management Service (OMS) then graphically representing the data can also be performed externally. One such tool that can be used to graph the data is GNU Plot.

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Monitoring GoldenGate replicat performance using 'flashback query'

By using a checkpoint table in the OGG replicat database, you can retrospectively review the replicat's lag using flashback query (with some limitations if you do not utilise a heart beat table).

Picture the scenario. You receive observations that the Oracle GoldenGate (OGG) replicat system that you are responsible for had fallen behind overnight and all overnight processing was performed against incorrect data. What do you do? Perhaps the observation was erroneous. How can you demonstrate this?

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Migrate/Upgrade Debian 7 Wheezy GNU/Linux from 32 bit to 64 bit HowTo

This HowTo converts a working 32 bit installation into a 64 bit system. You keep all programs, settings and data. You start with a 32 bit system that can run 64 bit programs, and finish with a 64 bit system that can run 32 bit programs. We firstly demonstrate an upgrade from 6.0 Squeeze 32 bit to 7 Wheezy because Debian 7 is a pre-requisite.

With the recent release of Debian GNU/Linux 7.0 Wheezy, a new feature called multiarch has been introduced. The facility permits the installation of executable files (such as libraries and programs) from multiple architectures simultaneously on the same system. The primary use of this is to allow 32 bit programs to be run on a 64 bit system, but there are more interesting possibilities. We can turn this on its head, allowing 64 bit programs to run on a 32 bit system, then ultimately replace all 32 bit programs with their 64 bit equivalents. No other operating system can provide this flexible feature.

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Upgrading GNU/Linux from 32 bit to 64 bit HowTo

This brief HOWTO shows how to take a working 32 bit 12.04 installation and convert it into a 64 bit system. You will be able to keep all your programs, settings and data. You start with a 32 bit system that can run 64 bit programs, then convert it to a 64 bit system that can run 32 bit programs.

With the upcoming release of Debian GNU/Linux wheezy, a new feature called multiarch is being introduced. The facility permits the installation of executable files (such as libraries and programs) from multiple architectures simultaneously on the same system. The primary use of this is to allow 32 bit programs to be run on a 64 bit system, but it has other uses.

With the release of Ubuntu LTS 12.04 (Precise Pangolin), this feature is available now.

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Complete guide to install and run Debian GNU/Linux on Asus WL-500W using OpenWRT

There are various articles describing how to install and run Debian GNU/Linux on USB flash memory on an Asus WL-500W. This guide differs in that it will provide a complete end-to-end set of instructions. All you need is an Asus WL-500W, USB flash memory (say, 2 GB in size), a computer to build the firmware and Debian root filesystem, and an Internet connection to get the source code for OpenWRT and packages for Debian.

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Multi-user on Doogee X6

The relatively new Android mobile cell phone from Doogee called the X6 has its multiple user account capability disabled.  The operating system is an old and non-standard Lollipop 5.1 Android, but the multi-user option should still be enabled in a phone of this operating system release.  Below are a few simple steps to enable it.  A prerequisite is installation of the Android Debug Bridge (ADB)

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Apache2 fails to start on boot (but subsequent manual starts work fine)

I migrated a virtual machine running the Apache 2 web server software on Debian wheezy GNU/Linux from Bytemark's legacy virtual machine infrastructure to their new BigV infrastructure. Staging this on my internal virtual infrastructure worked without a hitch. However, on the true infrastructure, Apache failed to start on boot with the following message. It would restart without issue if I then logged on and started it manually.

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'ACID' compliant NoSQL document database

Following on from FoundationDB's graph store, they are now proposing a document store.  Again, there is emphasis on 'ACID' compliance.  So, unlike most other newcomers to the database scene, their database will support the protections familar to RDBMS database administrators.  The database should be protected from interference and corruption, and benefit from protection of saved transactions.

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Migrate/Upgrade Ubuntu 14.04 LTS (Trusty Tahr) GNU/Linux from 32 bit to 64 bit HowTo

This brief HOWTO shows how to take a working 32 bit 14.04 installation and convert it into a 64 bit system. You will be able to keep all your programs, settings and data. You start with a 32 bit system that can run 64 bit programs, then convert it to a 64 bit system that can run 32 bit programs.

With the release of Ubuntu LTS 14.04 (Trusty Tahr), the ability to use the multiarch facility to upgrade to 64 bit is easier than ever. Much simpler than upgrading 12.04 and an evolution of upgrading Debian 7 or 8.

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Hibernation complete fix after upgrading to Ubuntu 14.04 LTS

Lots of issues with Gnome after upgrading Ubuntu GNU/Linux from 12.04 LTS to 14.04 LTS. The fix for most issues is to first login with the Ubuntu (Unity) session before choosing another session.

Anyway, hibernation ceases to be available after the upgrade.

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