Blogs about: Oracle Cost Based Optimizer
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OPTIMIZER_INDEX_CACHING Parameter
As previously discussed, the CBO assumes the actual costs and overheads associated with all I/Os to be the same, regardless of the type of I/O, unless told otherwise via the optimizer_index_cost_adj p… more →
Richard Foote's Oracle Blog
OPTIMIZER_INDEX_CACHING Parameter
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Richard Foote wrote 3 months ago: As previously discussed, the CBO assumes the actual costs and overheads associated with all I/Os to … more →
The CBO and Indexes: OPTIMIZER_INDEX_COST_ADJ Part II
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Richard Foote wrote 4 months ago: In OPTIMIZER_INDEX_COST_ADJ Part I, I discussed how this parameter can significantly impact the ove … more →
The CBO and Indexes: OPTIMIZER_INDEX_COST_ADJ Part I
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Richard Foote wrote 4 months ago: In the previous entry regarding The CBO and Indexes, we saw how the CBO with a query that selected 5 … more →
Function-Based Indexes and Missing Statistics (No Surprises)
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Richard Foote wrote 12 months ago: Thought I might mention a common trap associated with Function-Based Indexes following a recent ques … more →
Index Monitoring and Index Statistics (The Great Gig In The Sky)
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Richard Foote wrote 1 year ago: I write this post whilst listening to Pink Floyd’s masterpiece “The Dark Side Of The Moo … more →
Partition Pruning - Some Examples (Knives Out)
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Richard Foote wrote 1 year ago: Following on from my last post where I looked at the use of partition pruning vs. the use of an inde … more →
Regular Index vs. Partitions (The Best Of Both Worlds)
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Richard Foote wrote 1 year ago: When asking for requests and suggestions on what I could cover in the blog, Brian Tkatch asked … more →
Indexes and NOT Equal (Not Now John)
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Richard Foote wrote 1 year ago: The Cost Based Optimizer (CBO) is a rather complex piece of code that has to deal with countless dif … more →
NOVALIDATE Constraints Part II - Does It Matter ?
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Richard Foote wrote 1 year ago: As promised, more on NOVALIDATE constraints. As previously discussed, a Primary Key or a Unique Key … more →
Empty Leaf Blocks and Statistics (Sense Of Doubt)
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Richard Foote wrote 1 year ago: I’ve recently been discussing how empty index blocks or those blocks that contain nothing but … more →
Reading 100% of Data Via An Index (We Are Hungry Men)
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Richard Foote wrote 1 year ago: I’ve already previously discussed how a Full Table Scan can sometimes be the most effective ex … more →
Index Scan or Full Table Scan: The "Magic" Number (Magic Dance)
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Richard Foote wrote 1 year ago: What seems like ages ago, I listed 8 things you may not have known about indexes. Although I’v … more →
Store Indexes In A Larger Block Tablespace: The Multiblock Read Myth Part II (The Fly)
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Richard Foote wrote 1 year ago: Thought I might begin by mentioning a lovely little story by Billy Verreynne in this OTN Forum Threa … more →
Store Indexes In A Larger Block Tablespace: The Multiblock Read Myth (Karma Police)
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Richard Foote wrote 1 year ago: One of the great myths surrounding the use of differing block sizes is that storing indexes in large … more →
Store Indexes In a Larger Block Tablespace: Some Thoughts (Big Brother)
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Richard Foote wrote 1 year ago: A suggestion that seems to pop up on a routine basis on various forums and discussion boards is that … more →
Index Skip Scan - Does Index Column Order Matter Any More ? (Warning Sign)
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Richard Foote wrote 1 year ago: I’ve already written a few posts regarding concatenated indexes and things to consider (and no … more →
Index Compression Part IV (Packt Like Sardines In a Crushd Tin Box)
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Richard Foote wrote 1 year ago: A great question by Brian Tkatch has convinced me there needs to be at least a Part IV in this parti … more →
Oracle Diagnostic Tools - Some Random Thoughts (Hammer To Fall)
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Richard Foote wrote 1 year ago: There’s been a bit of discussion lately and some interesting opinions aired, such as those by … more →
Index Compression Part II (Down Is The New Up)
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Richard Foote wrote 1 year ago: Compression can be very beneficial when the compressed columns of an index have many repeated values … more →
