Comments on: Block Sizes

By: Book Review: Oracle Tuning: The Definitive Reference Second Edition « Charles Hooper's Oracle Notes

Sun, 28 Nov 2010 17:18:23 +0000

[...] (also the technical editor of this book) reported fixing the problem, and not the book author (reference reference2 reference3 [...]

By: Jonathan Lewis

Jonathan Lewis — Sun, 19 Sep 2010 12:32:00 +0000

Temporary note – I have just edited the file to delete some material but have not had time to adjust the page references in the blog note, so you may have to search backwards a few pages to find the relevant pieces. I will be updating the references some time in the next few days.

By: Rafi

Rafi — Thu, 15 Apr 2010 06:22:57 +0000

Nice explaination….

Thanks,

Rafi.

By: Faulty Quotes 5 – Block Sizes « Charles Hooper's Oracle Notes

Faulty Quotes 5 – Block Sizes « Charles Hooper's Oracle Notes — Sun, 31 Jan 2010 06:04:56 +0000

[...] Summary of an OTN forums thread – what was likely the longest thread ever on the topic of block sizes (and very likely multiple block sizes in the same database) from June 2008. The message thread was too large to be supported on the new OTN software due to performance reasons. Fortunately, Jonathan Lewis obtained a copy of the thread content in a PDF file: http://jonathanlewis.wordpress.com/2008/07/19/block-sizes/ [...]

By: Hemant K Chitale

Hemant K Chitale — Mon, 18 May 2009 09:11:51 +0000

A thread that you might want to comment on ?

http://forums.oracle.com/forums/thread.jspa?threadID=900977&tstart=0

Apparently, Indexes in a 16K block tablespace are very large. But we haven’t determined why.

By: Log Buffer #107: A Carnival of the Vanities for DBAs

Log Buffer #107: A Carnival of the Vanities for DBAs — Fri, 20 Feb 2009 21:15:41 +0000

[...] how to implement them efficiently. Ready to get deep into the internals? Jonathan Lewis has a good writeup on block sizes and how they can affect your application. For the dbas who work with Oracle RAC, [...]

By: Automatic DB_FILE_MULTIBLOCK_READ_COUNT | Structured Data

Automatic DB_FILE_MULTIBLOCK_READ_COUNT | Structured Data — Thu, 14 Aug 2008 12:02:06 +0000

[...] was from a post I wrote on the Oracle Forum: Database – General. I recommend that you read Jonathan Lewis’ summarization of the thread instead of reading all 671 posts (as of today). You will spend much less time and get [...]

By: Robert Klemme

Robert Klemme — Fri, 08 Aug 2008 07:08:54 +0000

Very good summary indeed, Jonathan! Everybody embarking on Oracle should probably read this.

For those lured to this posting by the “block size” keyword, Richard Foote has some excellent blog entries about whether to separate indexes to tablespaces with different block sizes, e.g. http://richardfoote.wordpress.com/2008/03/26/store-indexes-in-a-larger-block-tablespace-height-reduction-12-myth-five-foot-one/

By: lascoltodelvenerdi

lascoltodelvenerdi — Wed, 23 Jul 2008 09:16:28 +0000

What’s “shocking” is the fact that, many times, we build a table with no modification on the PCTFREE: we use standard values and “hope for the best”.

Nothing new: old problems still around! :)

Recently I worked on a project where many tables where “read only” and the fact table was a fat-quasi-only-insert one.

We choose to set a very low PCTFREE (about 1-2%) and suggest a db-block size of 8K. Ehm…standard db_file_multiblock_read_count for us.

In production this become PCTFREE 10% and db-block 32K! :|

Time for a “reorg”?

By: Tom Jurcic

Tom Jurcic — Tue, 22 Jul 2008 04:32:51 +0000

Its good to see things haven’t changed much from the days of Oracle 7.3.x when the block-size discussion was a hot-topic for Unix platforms. I can remember briefly discussing this topic with Jonathan (back in 1997, UK, Surrrey).