Author: Christo Kutrovsky

In Part 1 of the series, we covered in detail how the PQ_DISTRIBUTE can change the data distribution method across parallel query workers and the importance of avoiding BUFFERED hash joins. Through the remaining parts of the series, I showed…

Welcome to part 6 of the series. The USE_PARTITION_WISE_GBY hint is “brand new,” introduced in 12.2. I personally welcome this hint as I’ve cursed many times in the past due to the lack of control for this aspect of parallelism…

Welcome to part 5 of the series. First, some background: if you want to skip to the reference part, scroll down. This hint was introduced relatively recently – in Oracle 12.1 – where for the first time, SQL Windowing functions are…

Welcome to part 4 of the series. The GBY_PUSHDOWN is a very interesting hint, introduced in 10.2 – it doesn’t have the PQ prefix, but nevertheless plays a crucial role in Parallel query plans. Purpose: When GBY_PUSHDOWN is activated, an…

In part one of this series on Oracle Parallel Query Hints, I looked at PQ_DISTRIBUTE, and part two was about PQ_Replicate. Now, for the third part in the series, I will take a look at PX_JOIN>FILTER. The PX_JOIN_FILTER is a…

In part 1 of this series, we talked about the basic mechanics of the PQ_DISTRIBUTE hint. I did mention the PQ_REPLICATE, and here are all of the details. Oracle Database 12.2, has added a new feature that allows PQ processes…

One of the most powerful features of the Oracle database is its ability to leverage multiple cores spread across many RAC servers to execute a single query. Oracle’s optimizer tries its best to execute queries in the most efficient manner,…

Very often when reading data, we need to locate the most current record for a set of conditions. One typical example is that we read the data to find the most recent order for a particular customer. In this simple…

Christo Kutrovsky, ATCG Principal Consultant and Oracle ACE at Pythian, shares something useful he discovered by accident when playing with Auto DOP.

Christo Kutrovsky, ATCG Principal Consultant and Oracle ACE at Pythian, discusses the importance of hybrid databases, their challenges, and choosing the right database solution for your organization.