Voice of the DBA

Tag: sql server

  • The Flash Database

    I caught this piece on the impact of flash storage on database engine design this week. It’s interesting as there’s been debate for years as to whether SQL Server should alter its behavior if it detects SSDs being used for storage instead of physical disks. It doesn’t, and perhaps that’s fine, though the article makes me think there are performance gains to be had if behavior changes.

    The article really looks at a few of the NoSQL products, though the design changes aren’t necessarily specifically limited to those products. I particularly thought that two ideas in the piece were interesting: indexes in memory with data on disk and the realization that threading can be he bottleneck with SSDs. I’m not sure if Windows and/or SQL Server could use these ideas, but they are interesting.

    I do wonder sometimes if a little more control of indexes would be helpful in SQL Server. Imagine if I could limit a large slice of memory to strictly non-clustered indexes and then have other data on SSDs. Would there be a way to tune SQL Server to run better for some workloads? Perhaps the algorithsm that choose query plans would change if they knew a scan of an NCI could be completed in a fraction of the time that a seek took place on a CI? Maybe we’d be willing to perform more seeks on in-memory indexes before performing lookups on disk.

    The idea of more concurrent operations, requiring more threads, also seems to be an area where I could suspect that both Windows Server and SQL Server could benefit from SSDs. If the systems changed their read and write algorithms and used many more threads with SSDs, could we get more throughput? Should our systems be more aware of how many controllers and paths might be on a system? I wonder, especially as some of this hardware becomes cheaper and cheaper. I could certainly see more organizations looking at using lots of smaller SSDs for a few servers that require high performance than a SAN.

    However it’s not as though SQL Server isn’t trying to take advantage of technology changes. The In-Memory OLTP system  and Buffer Pool Extensions in SQL Server 2014 are designed to take advantage of more memory and SSDs to dramatically improve performance. I don’t know what else might be coming in the next version of SQL Server, but I do hope that as new ideas emerge, SQL Server considers taking advantage of them.

  • Disconnecting Auditing

    We know security is becoming more and more of a topic for IT professionals. As we realy more heavily on our computer systems, we have to be sure that the information contained in them is secure. We know that we can’t necessarily anticipate and protect the applications from every attack, but we can usually detect and respond to incidents. To do that, we need good auditing of all the events that occur.

    The problem, in my mind, is that our auditing efforts and implementations are too tightly tied to the administration of our systems. The auditing features must be configured by administrators, who are also often tasked with the review of the auditing data and logs. This is a fundamental problem as it’s entirely possible that an administrator or privileged user might be just the person that will violate security practices. With their rights inside of the computer system, it’s likely that the same person perpetrating the malicious activity would be able to easily cover up or remove any evidence of the incident.

    I think that auditing is fundamentally implemented poorly. Auditing features in software, including SQL Server, should be separated out from administration, perhaps even configured and enabled by a separate user or account than the person who administers the system. I would anticipate that a person in the finance or accounting departments at most companies might be responsible for managing the audit data. Even if they were unsure of the meaning of the data, having control over the information would prevent problems with the auditing data being compromised. I could even see auditing services being offered by third parties that interpret or review the data for companies without a dedicated security department.

    I doubt we’ll see a disconnect anytime soon, but I do think that the value of auditing is drastically reduced when we don’t have a strong separation of rights, responsibility, and capabilities between auditing and administration.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.5MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

    The Voice of the DBA podcast features music by Everyday Jones. No relation, but I stumbled on to them and really like the music. Support this great duo at www.everydayjones.com.

  • MS14-044–Security Alert for SQL Server

    I just saw this, but you should be aware. There’s a potential Denial of Service/Elevation of Privilege bug in SQL Server. Here’s the bulletin:

    MS14-044

    There are QFE and GDR patches for versions since 2008, but you need to read carefully to determine which one to install on your systems.

  • The Brittleness of Replication

    I’ve used replication for years in different positions. I first discovered it in SQL Server 6.5, using it to simulate a queuing system to keep two disparate applications in sync without requiring transactions between the applications and causing errors. As handy as replication was, it was also brittle. Small things would sometimes break replication and the quickest way to repair the system was to drop replication and re-initialize it. Fortunately my data was small in size.

    As I’ve watched replication grow through the years, I’ve been happy to see enhancements, like the ability to replicate schema changes to objects contained in articles. However I’ve been disappointed that the tooling has barely improved and the brittle nature of the process has not been addressed.

    It seems that as SQL Server grows, we find more and more features and subsystems that are being managed like replication. They get built and then languish with few resources devoted to improving their tooling and robustness. Service Broker, spatial data, and more are examples of features that were introduced, but have received little attention in newer versions.

    I have to believe there are developers at Microsoft that would love to make the product better. I understand the need for new features, and continuing sales, but devoting a percentage of time to improving existing features, regardless of the Connect votes or marketing wishes, would help make the platform that much better for everyone.

    Steve Jones

    The Voice of the DBA Podcast

    Listen to the MP3 Audio ( 2.2MB) podcast or subscribe to the feed at iTunes and LibSyn. feed

    The Voice of the DBA podcast features music by Everyday Jones. No relation, but I stumbled on to them and really like the music. Support this great duo at www.everydayjones.com.