Joe Chang

Enterprise Storage Systems - EMC VMAX

jchang — Fri, 10 May 2013 15:52:00 GMT

I generally do not get involved in high-end SAN systems. It is almost impossible to find meaningful information on the hardware architecture from the vendor. And it is just as impossible to get configuration information from the SAN admin. The high-end...(read more)

Relativity e-discovery on SQL Server

jchang — Fri, 26 Apr 2013 18:18:00 GMT

Back in late 2011 to early 2012, I was asked to look into issues for a SQL Server system supporting kCura Relativity. Relativity is an e-discovery platform, that is, a document search management system frequently used for document discovery is legal cases....(read more)

Excel Error or Idiot User?

jchang — Wed, 17 Apr 2013 20:01:00 GMT

Many of us have probably seen recent headlines titled Excel Error - major catastrophe, end of the world blah blah blah. No where in any of these is it cited that there was actually an error made by Excel. But if there was a mistake, people would rather...(read more)

Hyper-Threading Performance

jchang — Mon, 08 Apr 2013 13:15:00 GMT

The Hyper Threading technology returned to the Intel Xeon (and Core-ix) with processor codename Nehalem in 2009. It was first introduced with Willamette in late 2000?, and the first Xeon in 2001. But the Core 2 architecture, 2006, in the Xeon 5300 and...(read more)

Storage Performance

jchang — Mon, 25 Mar 2013 03:52:00 GMT

Storage has changed dramatically over the last three years driven by SSD developments. Most of the key components necessary for a powerful storage system are available and the cost is highly favorable for direct placement of data files. Some additional...(read more)

Job History row limiter

jchang — Tue, 05 Mar 2013 20:42:00 GMT

There are situations where guaranteed accuracy correctness is essential, which is why we have transactional databases meeting the ACID properties. And then there are situations where we just need an approximate number. An example is the size of the SQL...(read more)

EMC VNX2 and VNX Future

jchang — Mon, 25 Feb 2013 12:27:00 GMT

While going through the Flash Management Summit 2012 slide decks, I came across the session Flash Implications in Enterprise Storage Designs by Denis Vilfort of EMC, that provided information on performance of the CLARiiON, VNX, a VNX2 and VNX Future....(read more)

The Path to In-Memory Database Technology

jchang — Mon, 11 Feb 2013 21:08:00 GMT

The term in-memory database can be subject to misinterpretation. An in-memory database was originally used to describe a storage engine designed for the memory access characteristics of modern microprocessors, not simply a database stored in memory. Today...(read more)

Queries barely over the Cost Threshold for Parallelism

jchang — Thu, 15 Nov 2012 20:11:00 GMT

I had discussed SQL Server parallelism in Oct 2010, with my thoughts on the best settings for: Cost Threshold for Parallelism (CTP) and Max Degrees of Parallelism (MAXDOP) in Parallelism Strategy and Comments . At the time, I had intended to follow up...(read more)

SSDs at PASS 2012

jchang — Fri, 09 Nov 2012 05:30:00 GMT

There were 7 companies exhibiting SSD products as PASS this year, and one with a product to support SSD storage. This is not counting Dell, EMC and HP who have SSD products, but were at PASS for other reasons. This shows that many have aspirations with...(read more)

SSD-HDD price parity

jchang — Tue, 06 Nov 2012 02:21:00 GMT

It is hard to believe that we are essentially at SSD-HDD price parity? Of course I am comparing enterprise class 10K/15K HDDs to consumer grade SSDs. Below are prices I am seeing 600GB 15K 3.5in HDD $370 3TB 7.2K 3.5in HDD $400 300GB 15K 2.5in HDD $370...(read more)

Supermicro motherboards and systems

jchang — Mon, 29 Oct 2012 00:47:00 GMT

I used to buy SuperMicro exclusively for my own lab. SuperMicro always had a deep lineup of motherboards with almost every conceivable variation. In particular, they had the maximum memory and IO configuration that is desired for database servers. But...(read more)

Server Systems for SQL Server 2012 per core licensing

jchang — Mon, 29 Oct 2012 00:40:00 GMT

Until recently, the SQL Server Enterprise Edition per processor (socket) licensing model resulted in only 2 or 3 server system configurations being the preferred choice. Determine the number of sockets: 2, 4 or 8. Then select the processor with the most...(read more)

Decoding STATS_STREAM

jchang — Sat, 05 May 2012 10:16:00 GMT

Data distribution statistics is one of the foundations of the cost-based query optimizer in all modern database engines including SQL Server. From SQL Server 2005 on, most of the information displayed by DBCC SHOW_STATISTICS is kept in a binary field...(read more)

Intel Xeon E5 (Sandy Bridge-EP) and SQL Server 2012 Benchmarks

jchang — Wed, 07 Mar 2012 23:53:00 GMT

Intel officially announced the Xeon E5 2600 series processor based on Sandy Bridge-EP variant with upto 8 cores and 20MB LLC per socket. Only one TPC benchmark accompanied product launch, summary below. Processors Cores per Frequency Memory SQL Vendor...(read more)