TOI

Uwe Hesse's picture

How to move Partitions ONLINE and make them READ ONLY in #Oracle 12c

readonlyhttps://uhesse.files.wordpress.com/2017/01/readonly.png?w=574&h=60

Uwe Hesse's picture

Hot cloning and refreshing PDBs in #Oracle 12cR2

Hot cloning PDBs is new in 12.2, so you don’t have to put the source PDB into READ ONLY mode before the cloning if you have it in local undo mode. I suppose shared undo mode will become very unpopular. Another 12.2 New Feature is the option to clone a PDB that can be refreshed from the source PDB. I will show both features with this article, but you may of course do hot cloning without a later refresh. In this case, just leave out the REFRESH MANUAL clause and you don’t have to OPEN READ ONLY the cloned PDB afterwards. On a high level, what I demonstrate is this:

Uwe Hesse's picture

Happy New YouTube Channel!

As announced, I start into 2017 with my own YouTube channel. You can access it at the right upper part of this site by clicking on the red icon:

Uwe Hesse's picture

Happy New Year 2017!

fireworks-animation

Uwe Hesse's picture

How to upgrade a Pluggable Database to 12cR2 in #Oracle

pluginhttps://uhesse.files.wordpress.com/2016/12/plugin.png?w=112&h=150 1

Uwe Hesse's picture

How to configure FLASHBACK in #Oracle

flashhttps://uhesse.files.wordpress.com/2016/12/flash.png?w=600&h=524 600w, https://uhesse.files

Uwe Hesse's picture

New mean demo machine

My new Notebook is there! Will spend a couple of hours to do the setup. The specs are quite promising:

CPU:
Intel Core i7-6700 | 4 Cores | 8 Threads | 3,4 – 4,0GHz
Memory:
32GB  SO-DIMM DDR4 RAM 2400MHz Crucial Ballistix Sport LT
6 TB SSD Storage:
1TB m.2 Crucial MX300
1TB m.2 Crucial MX300
2TB Seagate FireCuda | 5400U/Min | 7mm
2TB Seagate FireCuda | 5400U/Min | 7mm

Okay it did cost me a fortune. See the new one on the left:

nc

Uwe Hesse's picture

#ukoug_tech16 Review with Tweets

UKOUG Tech16 is in its final hours, time for a special review: Tweets about it

It was in Birmingham again – very nice location!

 

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Standard Edition attracts not only my attention more and more

Uwe Hesse's picture

How to reduce Buffer Busy Waits with Hash Partitioned Tables in #Oracle

fight_contention_2https://uhesse.files.wordpress.com/2016/12/fight_contention_2.png?w=576&... 576w, https://uhesse.files.wordpress.com/2016/12/fight_contention_2.png?w=144&... 144w" sizes="(max-width: 288px) 100vw, 288px" />

Large OLTP sites may suffer from Buffer Busy Waits. Hash Partitioning is one way to reduce it on both, Indexes and Tables. My last post demonstrated that for Indexes, now let’s see how it looks like with Tables. Initially there is a normal table that is not yet hash partitioned. If many sessions do insert now simultaneously, the problem shows:

Uwe Hesse's picture

How to reduce Buffer Busy Waits with Hash Partitioned Indexes in #Oracle

fight_contentionhttps://uhesse.files.wordpress.com/2016/12/fight_contention.png?w=150&h=132 150w, https://uhesse.files.wordpress.com/2016/12/fight_contention.png 474w" sizes="(max-width: 300px) 100vw, 300px" />

Buffer Busy Waits can be a serious problem for large OLTP systems on both tables and indexes. If e.g. many inserts from multiple sessions occur simultaneously, they may have to compete about the same index leaf blocks like the picture below shows:

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