Combined ACCESS And FILTER Predicates – Excessive Throw-Away

Catchy title... Let's assume the following data setup:

create table t1
as
select
rownum as id
, 1 as id2
, rpad('x', 100) as filler
from
dual
connect by
level < = 1e4
;

create table t2
as
select
rownum as id
, 1 as id2
, rpad('x', 100) as filler
from
dual
connect by
level < = 1e4
;

create table t3
as
select
rownum as id
, 1 as id2
, rpad('x', 100) as filler
from
dual
connect by
(more...)

Video Tutorial: XPLAN_ASH Active Session History – Part 5

The next part of the video tutorial explaining the XPLAN_ASH Active Session History functionality continuing the actual walk-through of the script output.

More parts to follow.

DOAG Expertenseminar "Parallel Execution Masterclass" (German)

In zwei Wochen findet das Expertenseminar "Parallel Execution Masterclass" in Berlin statt, das ich gemeinsam mit der DOAG veranstalte.

Es sind noch ein paar Plätze frei - sollten Sie also Lust und Zeit haben, nach Berlin zu kommen und exklusives Wissen (nicht nur) über das Parallel Execution Feature der Oracle Datenbank zu erfahren, würde ich mich sehr freuen, Sie dort mit den anderen Teilnehmern begrüßen zu dürfen, um gemeinsam mit Ihnen eine gute und produktive (more...)

Video Tutorial: XPLAN_ASH Active Session History – Part 4

The next part of the video tutorial explaining the XPLAN_ASH Active Session History functionality continuing the actual walk-through of the script output.

More parts to follow.


12c Parallel Execution New Features: Concurrent UNION ALL – Part 3

In the final part of this instalment I want to focus on the possible optimisation of remote access that I outlined in the initial part, which is based on the idea of running multiple concurrent remote branches of a UNION ALL to overcome the query coordinator bottleneck of straightforward remote queries that need to transfer larger amounts of data.For that purpose I now simply change my sample query to access the serial table (more...)