Oracle

NLS_LANG on Windows in Europe: WE8MSWIN1252 or WE8PC850?

By Franck Pachot . In europe we have accents and non US7ASCII characters. We need special characterset. I’m not talking about Unicode here that solves all the problems. If you have a Java application, you have no problem: it’s(…)

Flashback logging overhead: ‘db file sequential read’ on UNDO tablespace

By Franck Pachot . in my previous post I’ve reproduced an issue where some bulk insert into a GTT was generating too much undo. But the real case I encountered was worse: the insert was reading lot of(…)

Insert into GTT: bulk with APPEND_VALUES

By Franck Pachot . This post is about the case I had where a GTT was generating too much undo. The effects were amplified by the fact that the database was in flashback logging (see Jonathan Lewis answer in(…)

Oracle multitenant dictionary: upgrade

By Franck Pachot . This is a second part of the previous post about metadata link. I’ve shown how a sharing=metadata function becomes a sharing=none function when it is changed in the pdb – i.e when not having(…)

Oracle multitenant dictionary: metadata links

By Franck Pachot . As in previous posts (1 and 2) I’m still playing with multitenant dictionary. You may wonder why I’m spending time to do unsupported things that we will never be able to use in(…)

Oracle multitenant dictionary: object links

By Franck Pachot . I’ve described Oracle 12c metadata and object links internals in a previous post. But before that, the first time I investigated on it, I made a wrong assumption because I was looking at AUDIT_ACTIONS(…)

Creating a schema synonym in Oracle – an unsupported feature

By Franck Pachot . Ivica Arsov (@IvicaArsov) has made an interesting comment about AUDIT_ACTIONS object link table. I’ll blog about it soon, but in the meantime when checking its definition in cataudit.sql it came upon the following:(…)

Oracle lateral inline view, cursor expression and 12c implicit statement result

By Franck Pachot . I’ll present here 3 ways to run a query for each result of another query. Let’s take an exemple: get all executions plan (select from dbms_xplan.display_cursor) for each of my queries (identified from v$sql). The(…)

Oracle 12c: Can we disable logging for DML?

By Franck Pachot . If we don’t mind about loosing our changes, then can we disable logging for DML? This is a question I’ve heard a lot. Ok, you don’t need to recover your changes but Oracle may want(…)

SQL*Plus COPY Command is back as BRIDGE

By Franck Pachot . Did you ever use the COPY command in sqlplus? It’s very old, and documentation says : The COPY command is not being enhanced to handle datatypes or features introduced with, or after Oracle8i. The(…)