When local partitions….aren’t

Let’s say I’ve got a partitioned table, and because New Year’s eve is coming around, I certainly don’t want to be called out at 12:01am because I forgot to add the required partition for the upcoming year Smile.

Since 11g, I can sleep easy at night by using the INTERVAL partition scheme. Here’s my table



SQL> create table t ( x date, y int )
  2  partition by range ( x )
  3  interval ( numtoyminterval(1,'MONTH'))
   (more...)

UKOUG 2016

Just a little video montage of the fun and learning from UKOUG.  A great conference every year.

I was fortunate enough to receive a Best Speaker award (from a 12c features talk given at the 2015 conference). I gave three talks, one of which was the Database Keynote for 2016 – I felt very privileged for the invitation to do so.  The slides for the talks can be found on the AskTom site (more...)

Multi-table insert

An interesting question came through on AskTom recently.  The requirement was to perform a single pass through a source table, and load the data into three target tables.

Now that’s trivially achieved with a multi-table insert, but there was a subtle “twist” on this requirement.  Each of the three target tables may already contain some, none or all of the rows from the source table.  Hence the requirement was to “fill (more...)

A 12.2 treat for the festive season

We’re being asked to store more and more data, yet keep backup windows, query performance and the like unchanged, no matter how much we store. As a result, more and more database shops are needing to partition their data. The problem is – partitioning data is a significant restructure of the data, which thus incurs a large outage and the accompanying planning and coordination.

Unless you’re on 12.2.

Here’s a demo where we can (more...)

Advanced Replication

Long before Streams, long before Goldengate, if you want to keep data between sites synchronised in some fashion, or even allow sites to independently update their data, there was the Advanced Replication facility in Oracle.  An “extension” of the concept of simple materialized views (or snapshots as they were called then), you could design complete replicated environments across Oracle databases.

But it was a non-trivial exercise to do this.  You had to be (more...)

max_enabled_roles – nice touch

Some people get very excited with roles, and quickly the number of roles proliferates to huge numbers…Until this happens

ORA-28031: maximum of 148 enabled roles exceeded

But in helping someone out on AskTom, I just found a nice touch in 11.2.0.4.  I had granted my account 200 roles (since the max_enabled_roles parameter is capped at 148), fully expecting to get the standard error when attempting to connect.  But I didn’t (more...)

Simple demo of message propagation

If you’re using AQ, then it’s simple to setup simple enqueue and dequeue facilities on your local database to provide all sorts of asynchronous style processing in your applications.  As long as you’re applications are designed and built to handle it, the “fire and forget” model to keep user applications responsive, and all of the “heavy lifting” done in the background is a very attractive one.

You can also use AQ to achieve the (more...)

Just one more week

image

I’m off to UKOUG again this year.  It’s an awesome conference, and I’ll be doing three talks there.

On Monday at 3:30 it’s my first keynote talk Smile  “12 Things You’ll Love About the Oracle Database 12.2”, followed up at 6pm by “AskTom – One Year On”.

On Tuesday, at 3:30 I’ll be doing a talk for anyone want to come up to speed on all of the partitioning features with “Partitioning 101”.

(more...)

Attribute clustering (part 3)

So in part1 and part2, we looked at creating tables with clustered data.  If you’re ready to climb aboard the attribute clustering heading toward Fastville Smile you might want to take an existing table and cluster it.  In part 2 we saw how we had to be extra careful with syntax.  The same rule applies with altering a table to cluster it.  Lets start with our SOURCE_DATA table which was not (more...)

Attribute clustering (part 2)

In the previous post, I demonstrated attribute clustering by

  • creating a table of source data which contained data in randomised order, via

SQL> create table source_data  as
  2      select d.*
  3      from dba_objects d
  4      where object_id is not null
  5      order by dbms_random.random;



  • and then it loading into a table with attribute clustering defined to cluster the data into the desired order.

The obvious question is then “Why not just cluster the (more...)