How many times have you had a developer come to you and say, “I just did a bad thing in the database. Can you recover from what I just did?”
In preparation for an upcoming talk about Oracle 12.2 I am planning on getting my feet wet with the Oracle 12.2 Sharding option. It seems to be a very interesting subject to get into, but like all new subjects, they can be intimidating at first due to their complexity. So why not use the instructions someone has already written down?
Oracle has a nice series of articles about Sharding. I found the Sharding landing page in the Maximum Availability Architecture section on OTN. For the purpose of this blog post I’m intending to follow the “Oracle Sharded Database Deployment with Active Data Guard using CREATE SHARD method for On-Premises – Cookbook”, available from the aforementioned landing page.
APRIL FOOLS After 5 1/2 years at Oracle Corporation, I’ve decided to leave and take on a very exciting new challenge !! President Trump’s office have accepted my nomination to head their IT department in Washington DC, where I’ll be responsible for ensuring all USA government data is stored in a extremely efficient and secure manner. So […]
I have a few presentations scheduled in IOUG Collaborate 2017, Las Vegas.
1. Session: 621: RAC Clusterware internals
**Date/time: Mon, Apr 03, 2017 (01:30 PM – 02:30 PM) : Jasmine A
2. Session: RAC cache fusion internals. ( OakTable track )
**Date/time: Wed, Apr 05, 2017 (09:45 AM – 10:45 AM) Room: South Seas C
3. Session: 479: An in-depth review of ASM and internals
**Date/time: Wed, Apr 05, 2017 (02:45 PM – 03:45 PM) : Palm B
Presentation files ( Updated after the presentations).
Thank you for coming to my presentation(s).
The following question came up on the OTN database forum recently:
We have below table with columns,
Table T1 Columns: ----------- Col_1, Col_2, Col_3, Col_4, Col_5, Col_6, Col_7, Col_8, Col_9, Col_10, Col_11, Col_12, Col_13, Col_14, Col_15
on which below indexes are created.
XXTEST_Col_1 Col_1 XXTEST_Col_2 Col_2 XXTEST_Col_3 Col_3 XXTEST_Col_5 Col_5 XXTEST_Col_6 Col_6 XXTEST_Col_7 Col_7 XXTEST_Col_8 Col_8 XXTEST_Col_8 (Col_4, Col_10, Col_11)
I have requirement to update table T1 as below and it’s taking really long. [JPL: I’m assuming that the naming of the second xxtest_col_8 index is a trivial error introduced while the OP was concealing names.)
If you are running Application Express, there is a new patch available. Lots of fixes which you can read about here
I just downloaded patch 25341386 and followed the installation instructions and it went through with no problems at all in just a few minutes.
I’ve waxed lyrical in the past about creating suitable column group statistics whenever you drop an index because even when the optimizer doesn’t use an index in its execution path it might have used the number of distinct keys of the index (user_indexes.distinct_keys) in its estimates of cardinality.