Using Legacy Methods to Lessen SQL Server 2014 Cardinality Estimator Skews

This post is a continuation of the SQL Server 2014 Cardinality Estimator enhancements exploration series: A first look at the query_optimizer_estimate_cardinality XE event “CSelCalcCombineFilters_ExponentialBackoff” Calculator “CSelCalcCombineFilters_ExponentialBackoff” Calculator– Part II The CSelCalcAscendingKeyFilter Calculator Cardinality Estimation Model Version Comparing Root-Level Skews in the new Cardinality Estimator In the previous post, I looked at root-level cardinality estimates vs. […]

Comparing Root-Level Skews in the new Cardinality Estimator

This post is a continuation of the SQL Server 2014 Cardinality Estimator enhancements exploration series: A first look at the query_optimizer_estimate_cardinality XE event “CSelCalcCombineFilters_ExponentialBackoff” Calculator “CSelCalcCombineFilters_ExponentialBackoff” Calculator– Part II The CSelCalcAscendingKeyFilter Calculator Cardinality Estimation Model Version In the previous post I showed you how to start using the new SQL Server 2014 CE model, but […]

Cardinality Estimation Model Version

This post is a continuation of the SQL Server 2014 Cardinality Estimator enhancements exploration series: A first look at the query_optimizer_estimate_cardinality XE event “CSelCalcCombineFilters_ExponentialBackoff” Calculator “CSelCalcCombineFilters_ExponentialBackoff” Calculator– Part II The CSelCalcAscendingKeyFilter Calculator In this post I just wanted to step back and discuss how to enable and identify the Cardinality Estimator version, at least as […]

The CSelCalcAscendingKeyFilter Calculator

This post is a continuation of the SQL Server 2014 Cardinality Estimator enhancements exploration series (yeah – I’ve decided to call this a series, since there will be quite a bit to talk about, time permitting): A first look at the query_optimizer_estimate_cardinality XE event “CSelCalcCombineFilters_ExponentialBackoff” Calculator “CSelCalcCombineFilters_ExponentialBackoff” Calculator– Part II So for this post, I […]

“CSelCalcCombineFilters_ExponentialBackoff” Calculator– Part II

At the end of my last post, “CSelCalcCombineFilters_ExponentialBackoff” Calculator I gave the following homework: Homework assignment – add another member column to the mix that has a 0.100 selectivity (for example – county) and compare the estimates using a pre-2014 and 2014 CTP2 compatibility mode. Here is the answer-key.  I’ll start off with adding a […]

“CSelCalcCombineFilters_ExponentialBackoff” Calculator

One more post for the day, just while I have the blogging bug… Per my last post, we saw that the query_optimizer_estimate_cardinality event can provide some interesting information in SQL Server 2014 around how cardinality estimates get calculated. I have a setup I’ve used in the past to demonstrate column correlation challenges (see my post, […]

A first look at the query_optimizer_estimate_cardinality XE event

This weekend I set up a Windows Azure virtual machine running SQL Server 2014 CTP2 (12.0.1524).  I had a local copy of SQL Server 2014 CTP2 in VMware as well, but thought it would be more fun to explore it on Windows Azure (kill two explorations with one stone).  On a side note, I’m really […]