An implied (not implying) permissions function

I’d always wondered why they didn’t make the “ImplyingPermissions” function (code is part of the books online) part of the product. I originally thought it was because the function was subtly (or not so subtly) misnamed. What the function does, is “given a permission in a permission class, return a table of which built-in permissions […]

Batch Mode improvement for columnstores in SQL Server 2014 CTP1

This post is a continuation of my previous posts on columnstore indexes in SQL Server 2014 CTP1 and query plans. The test bed is the same as in previous posts, based on an enlarged version of a fact table in AdventureWorks2012DW. One of the things that improves query speed when using columnstore indexes is the usage of […]

Columnstore indexes and cardinality estimates in SQL Server 2014 CTP1

This post is a continuation of my previous post about SQL Server 2014 Columnstore and Query Plans. I’ll take a look at how the new cardinality estimates affects columnstore index query plans. I’ve written a bit about the new cardinality estimator in SQL Server 2014, as well as looked into how to tell what the […]

Columnstore Indexes and Query Plans in SQL Server 2014 CTP1

Today I thought I’d try out some of the new, highly-touted columnstore improvements in SQL Server 2014. First off, to figure out what’s new I used three main sources: one is the “canon”, the whitepaper, “Enhancements to SQL Server Column Stores“, presented at Sigmod 2013. The second source is the SQL Server 2014 CTP1 Books Online […]

Tracing The New Cardinality Estimation in SQL Server 2014

According to the whitepaper “Mission-Critical Performance and Scale with SQL Server and Windows Server” there’s a new cardinality estimator in SQL Server 2014. The whitepaper doesn’t say a lot about how it works, but does mention “trace information will be provided”. That’s XEvent trace of course, and the trace event is “query_optimizer_estimate_cardinality”. I decided to […]

New query plan items in SQL Server 2014 CTP1

Every new version of SQL Server includes new or expanded features that effect query plans. Most (sometimes not all) of the query plan changes (and most of the functionality changes) can be discovered by “diff-ing” the XML schema for query plans between the current/new version and the previous version. I’ve done this before to enumerate […]

Hekaton, read committed isolation, and statement-level inconsistency

It’s stated in SQL Server 2014 Books Online that “The following isolation levels are supported for transactions accessing memory-optimized tables: SNAPSHOT, REPEATABLE READ, and SERIALIZABLE”. But later on, on the same page, it’s stated the “The isolation level READ COMMITTED is supported for memory optimized tables with autocommit transactions”. “Autocommit transaction” is just another way […]