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Non use of persisted data – Part Three

A long time ago I looked at some reasons as to why persisted computed columns ( and therefore indexes on those columns) are not used (Part1, Part2). Recently I was drawn into an issue where the same thing was happening, a persisted computed column had been created with an index, but neither were being used when […]

SQLBits Session “T4 Templating within SSDT using SQL Server 2014”

Very pleased that my session on “T4 Templating within SSDT using SQL Server 2014” has been excepted for SQLBits 12.   SQL 2014 and the latest SQL Server Data Tools has made T4 much easier to use in SQL Development Projects. I gave a talk last month on ETL Design for Warehouse loads to the London SQL User Group.  The […]

Manchester and Leeds user groups – 16/17 Oct

Thanks to all those that turned out of Wednesday and Thursday night in Leeds and Manchester to hear my presentation on Estimation and Statistics.  The ‘lucky’ Manchester crowd also got to hear ‘Trace Flag fun’, a deep dive into optimizer internals. As promised here are the slides and scripts:   Estimation and Statistics TraceFlag Fun […]

A quickie post on debugging

I’m not a great fan of the debugging feature in management studio, It always strikes me that to get any use from it then you are iterating (looping) too much ie doing TSQL wrong.  TSQL is not a procedural programming language and the debugger would seem to be most useful if you did develop TSQL […]

Nearing Nirvana with Hekaton

Rarely does a piece of technology make a difference to a system without someone (developer, DBA, architect etc) sitting down and thinking about how to apply the technology to their problems. For me one of the big pain points in TSQL development is that arrays/in memory storage are missing. If I wish to hold some […]

How full are your Hekaton Buckets ?

Hekaton is a really interesting technology, but is a world away from the functionality that we know and love. The SQL team have done a great job of disguising this departure from us by integrating it inside the SQL Server engine but none the less is a different beast entirely. Although the ultimate aim, I […]

Hekaton CTP1 – Row order limitation

UPDATE : Good news, this post relates to CTP1 only, the 8000 row limit has been lifted in CTP2 If you have been reading about hekaton and compiled stored procedure you are probably full of aspirations to move all your data into memory and magically have your system for faster. Slow down just a minute […]

Examining Hekaton Code

In my previous post, I made reference to a Microsoft Research paper on Hekaton Internals. This states that the SQL Engine produces C code which is then compiled to a DLL. So that would leave you to the assumption that there is a C file somewhere that can be looked at to find out some […]

First steps into Hekaton – XE Slow parameter passing

If you are anything like me then you will have already downloaded and installed the CTP1 release of SQL Server 2014. There are a lot of things of interest here, probably top of most peoples list is Hekaton, the new in memory OLTP transactionally compliant database. There are some bold claims with hekaton but to […]

SQLRelay – Cardiff and London – Estimation and Statistics

The basis of query optimization is Estimation and Statistics.  Without a decent estimation of the amount of rows to be processed, then the entire query plan could well be ‘wrong’.  These estimations are built via the statistics and the interactions between them is vital piece of understanding. With this in mind its always a great […]