OOW16 – The Park Central

Some of my sessions this year at OpenWorld are at the Park Central.

So…you’ve arrived at the Moscone Center, and you’re wondering “How do I get to the Park Central ?  After all…that’s where all of the hot talks will be” Smile

Here’s my simple guide:

1) From Howard St, head up the stairs next to the Moscone Center entrance


2) Walk down through Yerba Buena Gardens… You can’t miss them, they are a great grassy (more...)

A bumper OpenWorld 2016 for me…

My first OpenWorld was in the Australia in ..well… I’m not sure when Smile but it might have even been the late 1990’s.  Time flies.

But 2016 will be my first OpenWorld as an Oracle employee…and hence, I’ll be busy Smile

Hopefully you can come along to some or all of the sessions I’m involved in…or you can probably catch me during the week at the OTN lounge.

I’ll blog more shortly on how I can (more...)

Syntax formatter might change your data

I saw this on an AskTom question today answered by my colleague Chris.  Check out this simple example

SQL> create table T (
  2    x int default 1,
  3    y int default 1
  4   ,z int);

Table created.

It looks like I’ve assigned a default of “1” to both X and Y. But lets now dump out the default definition from the dictionary.

SQL> set serverout on
SQL> declare
  2    longcol varchar2(200);
  3   (more...)

Uber’s move to MySQL

I was reading a very interesting article on Uber’s move from Postgres to MySQL. I really like it when IT professionals and/or companies take the time to explain their technology decisions.  It’s a brave thing to do, because it’s easy for people to jump on the bashing bandwagon (“Ha ha … Company X chose Y and now they’re bust” etc etc).  It’s the same reason you rarely see detailed customer reference information (more...)

Little enhancements are always nice

Before LATERAL and CROSS APPLY were added (exposed to us) in 12c, a common technique to do correlated joins was using the TABLE/MULTISET technique.

For example, we might have had a couple of tables:

SQL> create table t as
  2  select object_type, min(created) min_dte, max(created) max_dte
  3  from dba_objects
  4  where owner = 'SCOTT'
  5  group by object_type;

Table created.

SQL> select * from t;

------------------- --------- ---------
INDEX               09-OCT-13 09-OCT-13
TABLE                (more...)

OpenWorld 2016 is not far away

OpenWorld is just around the corner, and the Ask Tom team will be involved in a number of panels where you can chat to us, ask questions, debate topics and basically have a relaxed 45mins during all the frenzied activity that is OpenWorld.  So if you’ve got any questions you would like answered “face to face”, rather than via Ask Tom, either drop them as a comment here, or feel free to post them (more...)

Can a query on the standby update the primary ?

You would think that (with the exception of the V$ tables which are predominantly memory structures reflecting the state of various parts of the database instance) a query on a read-only standby database would have absolutely no interaction with the primary.  After all, the standby database needs to be able to run independently of the primary should that primary database be down, or destroyed.

But there’s an exception to the rule.  Consider the (more...)

LAG / LEAD quick tip

As most of us know, with LAG and LEAD or more generally, any analytic function that may extend “past” the boundary of window it is operating on, you can get null as a result.

Here’s a trivial example

SQL> create table t as
  2  select rownum x
  3  from dual
  4  connect by level <= 10;

Table created.

SQL> select x, lag(x) over ( order by x ) as lag_Test
  2  from t;

         X    (more...)

Direct mode operations on IOT’s

An AskTom contributor brought to my attention, that direct mode insert on index organized tables now appears possible in 12c.  We can see the difference by running a simple script in both v11 and v12

SQL> select * from v$version;

Oracle Database 11g Enterprise Edition Release - 64bit Production
PL/SQL Release - Production
CORE      Production
TNS for  (more...)

dbms_output and the scheduler

One of the nifty things in 12c is the ability to pick up DBMS_OUTPUT output from your scheduler jobs. So if you haven’t built an extensive instrumentation or logging facility, you’ll still have some details you can pick up from the scheduler dictionary views. Let’s look at an example

SQL> create or replace
  2  procedure do_stuff is
  3  begin
  4    dbms_output.put_line('Commenced');
  5    dbms_lock.sleep(30);
  6    dbms_output.put_line('Working');
  7    dbms_lock.sleep(30);
  8    dbms_output.put_line('Done');
  9   (more...)