Author Archives

Reconstructing oratab from the cluster registry

At the Accenture Enkitec Group we have a couple of Exadata racks for Proof of Concepts (PoC), Performance validation, research and experimenting. This means the databases on the racks appear and vanish more than (should be) on an average customer Exadata rack (to be honest most people use a fixed few existing databases rather than …

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Investigating the wait interface via gdb.

For some time now, I am using gdb to trace the inner working of the Oracle database. The reason for using gdb instead of systemtap or Oracle’s dtrace is the lack of user-level tracing with Linux. I am using this on Linux because most of my work is happening on Linux. In order to see …

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Compressing sqlplus output using a pipe

Recently I am involved in a project which requires a lot of data to be extracted from Oracle. The size of the data was so huge that the filesystems filled up. Compressing the output (using tar j (bzip2) or z (gzip)) is an obvious solution, but this can only be done after the files are …

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Introduction to the Oracle database machine

For those of you who haven’t followed all the Oracle Exadata and database machine information, and want a brief introduction to the database machine: here it is! The confusion There is some confusion about ‘exadata’ and ‘the database machine’. If we look at the official product names, ‘Exadata’ is the storage server, and the ‘Database […]