Comments on: Upgrades

By: Dynamic Sampling (II) – Controlling The Activity – Part 1 – All Things Oracle

Thu, 08 Mar 2012 12:20:57 +0000

[...] 11.2.0.1). This setting acts as an umbrella for all the parameters controlling the optimizer (see this recent post by Jonathan Lewis for more information) including the various bug fix controls that can be seen [...]

By: laimis (lnd)

laimis (lnd) — Fri, 24 Feb 2012 09:18:59 +0000

That’s a post of real interest. We are in progress of migrating into 11R2.

11.2.0.3 bug list (Doc ID 1348336.1) consists largely of optimizer related bugs. Some of them sound scary:

“13514126 Wrong results due to missing single column range predicate caused by fix to bug 8275054″

Generally, it looks like large number of optimizer improvements resulted into equally large number of serious (wrong results or query crash) bugs.

By: Log Buffer #260, A Carnival of the Vanities for DBAs | The Pythian Blog

Log Buffer #260, A Carnival of the Vanities for DBAs | The Pythian Blog — Fri, 24 Feb 2012 06:01:33 +0000

[...] Jonathan Lewis is taking a look at recent developments in the “fix control” list, and the “optimizer environment” parameters. [...]

By: Kevin Angus

Kevin Angus — Thu, 23 Feb 2012 08:34:37 +0000

Surprisingly honest naming convention for _nested_loop_fudge and _query_rewrite_fudge :)

By: laimis (lnd)

laimis (lnd) — Tue, 21 Feb 2012 13:53:34 +0000

Here are statistics for my Oracle 11.2.0.2.2:

v$sys_optimizer_env/X$QKSCESYS
Version v$ count x$ count
11.2.0.2(psu2) 49 313

v$system_fix_control / x$qksbgsys
version count
11.2.0.2(psu2) 551

By: Timur Akhmadeev

Timur Akhmadeev — Tue, 21 Feb 2012 09:36:18 +0000

For ease of use of V$SESSION_FIX_CONTROL I've wrote a simple script called bug.sql. Each time I see something unusual related to, say, join elimination, I run @bug elimination and it gives clue what's next. Or to report what's new: @bug 11.2.0.3