Oracle 12c

Oracle 12cR2: DDL deferred invalidation

By Franck Pachot . In a previous post I described the new V$SQL views about rolling invalidation. I did the example with dbms_stats which is able to do rolling invalidation since 11g. But more is coming(…)

Oracle 12c and RMAN automatic datafile creation

By William Sescu A lot of new features popped up with RMAN 12c, like  Expansion of Multi-section support, or Simplified cross-platform migration and many many more. However, in this post I would like to highlight a small, but very helpful(…)

Oracle 12cR2: IS_ROLLING_INVALID in V$SQL

By Franck Pachot . In a previous post I published a test case to show when a cursor is not shared anymore after a rolling invalidation. Basically the dbms_stats marks the cursor as 'rolling invalid' and(…)

Oracle 12cR2 Optimizer Adaptive Statistics

By Franck Pachot . When 12.1 came out, the major issue we encountered after migration was related to the new adaptive features of the optimizer: automatic reoptimization, SQL Plan Directives and the resulting dynamic sampling. Of course, Oracle product managers(…)

Oracle 12cR2 Long Identifiers

By Franck Pachot . This morning during Gerald Venzl presentation of "What’s New for Developers in the Next Generation of Oracle Database" at Oracle Open World, one feature has been acclaimed by a full room: 12.2 show the end of(…)

Oracle Database 12.2 – PDBaaS

By Franck Pachot . It's official, Larry Ellison made the announcement at first keynote and the database product team at oracle has released the version and the documentation publicly. Oracle Database Exadata Express Cloud Service is the 'Cloud First' environment(…)

Oracle 12cR2 SQL new feature: LISTAGG overflow

By Franck Pachot . LISTAGG was a great feature introduced in 11g: put rows into line with a simple aggregate function. 12cR2 adds an overflow clause to it. What happens when you have so many rows that the LISTAGG(…)

Multitenant thin provisioning: PDB snapshots on ACFS

By Franck Pachot . Database on ACFS is a long story. At first, the main reason for ASM was to bypass a filesystem layer that is not required by the database. ACFS was for the non-database files that had to(…)

Adaptive Plans and cost of inactive branches

By Franck Pachot . Here are the details about an execution plan screenshot I've tweeted recently because the numbers looked odd. It's not a big problem, or maybe not a problem at all. Just something surprising. I don't like when(…)

AUDIT_SYS_OPERATIONS and top-level operation

By Franck Pachot . SYSDBA is powerful. You should use it only when you need to. And you should audit what is done when connected SYSDBA. This is achieved by AUDIT_SYS_OPERATION. But do you have an idea how much audit(…)