One of the difficulties with trouble-shooting is that’s it very easy to overlook, or forget to go hunting for, the little details that turn a puzzle into a simple problem. Here’s an example showing how you can read a bit of an AWR report and think you’ve found an unpleasant anomaly. I’ve created a little model and taken a couple of AWR snapshots a few seconds apart so the numbers involved are going to be very small, but all I’m trying to demonstrate is a principle. So here’s a few lines of one of the more popular sections of an AWR report:
Now that I’ve loaded a ton of transactions and did a bunch of work load on my source database with the SH sample schema and Swingbench, I’ve noted how little impact to the databases using different cloud tools, (which will come in a few later posts) now I’m going to show you how easy it is to create a new VDB from all of th
Recently I was applying the data dictionary part from an (exadata bundle) patch and ran into the following errors:
Most people know I like to do things the hard way…
The following is a straight, continuous, untouched, cut-n-paste from an SQL*Plus session on 22.214.171.124. How come the update doesn’t execute in parallel – noting that parallel DML has been enabled and the tablescan to identify rows to be updated does execute in parallel ?
A question has just appeared on OTN describing a problem where code that works in 11g doesn’t work in 12c (exact versions not specified). The code in question is a C-based wrapper for some SQL, and the problem is a buffer overflow problem. The query supplied is as follows:
select T1.C1 from T1, T2 where T1.C1 = T2.D1;
The problem is that this works in 11g where the receiving (C) variable is declared as
char myBuffer ;
but it doesn’t work in 12c unless the receiving variable is declared as:
Recently, I was trying to setup TDE. Doing that I found out the Oracle provided documentation isn’t overly clear, and there is a way to do it in pre-Oracle 12, which is done using ‘alter system’ commands, and a new-ish way to do it in Oracle 12, using ‘administer key management’ commands. I am using version 126.96.36.199.170117, so decided to use the ‘administer key management’ commands. This blogpost is about an exception which I see is encountered in the Januari 2017 (170117) PSU of the Oracle database, which is NOT happening in Oracle 12.2 (no PSU’s for Oracle 12.2 at the time of writing) and Oracle 188.8.131.52 April 2016 and October 2016 PSU’s.
In order to test the wallet functionality for TDE, I used the following commands:
A recent posting on the OTN database forum described a problem with an insert (as select) statement that sometimes ran extremely slowly: nothing interesting yet, there could be plenty of boring reasons for that to happen. The same SQL statement (by SQL_ID) might take 6 hours to insert 300K rows one night while taking just a few minutes to insert 900K another night (still nothing terribly interesting).