Oracle

Oracle 12c: comparing TTS with noncdb_to_pdb

By Franck Pachot . How to migrate from non-CDB to CDB? Of course all known migration methods works. But there is also another solution: upgrade to 12c if necessary and then convert the non-CDB to a PDB. This is(…)

When Oracle resets session statistics

By Franck Pachot . During our Oracle 12c New Features workshop I had a very good question about whether the session statistics are reset or not when doing ALTER SESSION SET CONTAINER. My initial thought was that they(…)

Oracle 12c privilege analysis rocks

By Franck Pachot . 12c came with a very nice feature: privilege analysis. You don’t know which privileges are required? then just grant DBA, run your application, and check which minimal privileges are needed. And today, I’ve discovered how(…)

Oracle locks: Identifying blocking sessions

By Franck Pachot . When you have sessions blocked on locks, you probably have all information about the waiters (they call you and anyway their waiting session is visible in v$session our ASH). But you usually need to get(…)

12c SQL Plan Directive: state has changed between 12.1.0.1 and 12.1.0.2

By Franck Pachot . SQL plan Directives have been introduced in 12c. If you have scripts that check their states (and I have that as I prefer to monitor closely the features that are new) you probably have seen(…)

AWR does not store explain plan predicates

By Franck Pachot . What is the most important part in an execution plan? It’s probably the predicate section. It helps to see implicit conversions. It helps to understand why an index is used or not. Or to see(…)

12.1.0.2 CDB views are now using CONTAINERS()

By Franck Pachot . I’ve blogged about multitenant internals at the time when 12.1.0.1 was just released. Something has changed in 12.1.0.2 and blogging about it was in my todo list for a long time. Now the occasion(…)

Oracle SQL Profile: why multiple OPT_ESTIMATE?

By Franck Pachot . In a previous blog I’v shared my script to retrieve the OPT_ESTIMATE hints from a SQL Profile. In the example I made, I had two lines for each table: --- PROFILE HINTS from dbiInSite(…)

Oracle SQL Profiles: Check what they do before accepting them blindly

By Franck Pachot . People often ask me if I use the SQL Tuning Advisor. The answer is no, at least not through the end of it. But don’t take me wrong. SQL Tuning Advisor is a really nice(…)

Using tmux for semi-interactive demos

By Franck Pachot . You are a speaker and like to show some demos. Which kind of demo do you do? you script everything so that you just have to press ‘enter’ during the demo you prepare everything in(…)