Showing entries 1 to 4
Displaying posts with tag: crosstab (reset)
Percona Live Amsterdam - September 21-23, 2015

I am attending Percona Live Amsterdam 2015 on September 21-23, 2015.

I will be on stage three times:

My first talk is a topic that has ben among my favorites for long time: I published an article about it in 2001, and several …

[Read more]
MDX: "Show Parents" - Redux: A generic and systematic MDX query transformation to obtain the lineage of each member

A couple of months ago I wrote about how you can use the MDX functions Ancestors() and Ascendants to retrieve the full lineage of members. (See: "MDX: retrieving the entire hierarchy path with Ancestors()".)

As you might recall, the immediate reason to write about those functions was to find a pure MDX solution to implement the "Show Parents" / "Hide Parents" functionality offered by OLAP cube browsers. To recap, developers of MDX-based pivot tables face a challenge when rendering the result of a query like this:

SELECT CrossJoin(
[Read more]
Crosstabs cell-shifting

A crosstab query is a specific query used to create aggregate reports on two or more fields, it’s  a handy way to display summary information. At Open Query we have customers using that trick to display production schedules.

The summary table is generated from the database to extract the manufacturing date (mand), unit number (unitn), product area (pro_area), and ranking (rnk). Then we can start using that summary table to process our crosstab. The summary table looks like this:

mand unitn pro_area rnk
2009-12-15 587-MWI2-PP49 1 11
2009-12-15 587-MWI2-PP50 1 10
2009-12-16 …
[Read more]
Multi dimensional cubes in MySQL through Gearman

I gave two presentations about Gearman at the As part of the preparation for these talks, I created several sample applications. One of them, about remote replication administration, I will cover in a separate post. The most amazing one, which I cover here, is a quick and painless solution for multiple level crosstabs in MySQL.

Some background is needed. Crosstabs (also called data cubes or pivot tables, have been one of my favorite hacks for long time. In 2001 I wrote an article about a simple …

[Read more]
Showing entries 1 to 4