Learning is not a spectator sport

Complete listing of posts

  • How important is "up to date" to you ?

    I wrote a post a while back showing how one of the options with an Oracle Text index is to keep that index perfectly updated with its underlying table.  (Long termers with Oracle may know that this is a relatively recent addition to Text indexes, which historically were updated with calls to CTXSYS.CTX_DDL.SYNC_INDEX, either on… Read more

  • 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” Here’s my simple guide: 1) From Howard St, head up the stairs next to… Read more

  • A bumper OpenWorld 2016 for me…

    My first OpenWorld was in the Australia in ..well… I’m not sure when 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 Hopefully you can come along to some or all of the sessions I’m involved in…or you… Read 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… Read 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… Read 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… Read 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… Read 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… Read 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 <=… Read 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; BANNER ——————————————————————————– Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 – 64bit Production PL/SQL Release 11.2.0.4.0… Read 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… Read more

  • Granular detail from a summary

    We had an interesting question on AskTom a few days ago.  Given a set of 12 values (forecasts in this case), one for each month of the year , can we manufacture a set of weekly forecasts for the same period.  Now it is perhaps a little dubious to “invent” detailed data out of summarised… Read more