Why Build a New SQL Database?
When I’m at conferences or meetups and people discover I work for a company building a new database, there are usually a few puzzled looks. Explaining the technology behind Akiban to people is easy but the usual reason for the puzzlement is that many people wonder why on earth a company would want to develop a new database from scratch when so many alternatives already exist.
There are good reasons, but I’ve struggled with articulating them especially when someone wants a 90 second explanation at a conference. In the interest of having an answer that I can easily refer people to, here’s what I think we’re trying to do. These are the problems that Akiban is aiming to solve.
Problems Akiban Solves
1) The object-relational impedance mismatch
Frequently referred to as the “vietnam of computer science” by some people, this problem is defined by Wikipedia as:
“a set of conceptual and technical difficulties that are often encountered when a relational database is being used by a program written in an OOO programming language or style”
Typically, each class in an application is mapped to a table in the backend database with the fields of that class being columns of the table and each instance of that class is a row in the corresponding table. In Akiban, application objects map to what we call table groups. Table groups are fundamentally a way of storing data - we store data as interleaved rows in a B+ Tree. Or more simply put, Akiban stores data hierarchically.
This makes integration of Akiban with existing ORM’s an interesting proposition since we expose methods of retrieving table groups directly through SQL. For example, Mike Bayer recently implemented support for Akiban in the SQLAlchemy ORM for Python. We are also working on support for Doctrine in the PHP world and ActiveRecord in the Ruby world.
Dr. Eric Brewer also touched on this in his closing talk at RICON 2012 (which seems to have been an excellent conference based on the posted videos). One quote from Dr. Brewer that really stuck out in my mind was - “instead of clean database where tables are joined at last minute. I actually want to have pre-joined them. I don’t really want to do more than 1 query”. That ties in nicely with what we allow by exposing methods to retrieve table groups or part of a table group with nested SQL i.e. in 1 query, an entire table group or part of a table group can be retrieved.
2) SQL (performance) doesn’t have to suck
SQL gets a bad rap. I’m not 100% sure if that’s because people don’t like the language or if it’s that people think that the performance of SQL queries are terrible due to poor experiences. Perhaps its a little bit of both. What’s great about SQL is that so-called ‘neck-tie’ programmers can easily use this declarative language to interact with a database system. To quote again from Dr. Brewer’s RICON talk - “having a language for them is a good idea. nosql does not really talk to these people”.
SQL can be used to solve many problem types. I once heard someone quip, “there’s a SQL query for that”, meaning it’s likely there are not many problems out there SQL cannot solve.
SQL performance in Akiban is greatly improved due to table grouping and the fact that our entire system (in particular our query optimizer and execution engine) is built from the ground up with this storage architecture in mind. First off, queries that join tables within a single table group can execute without the need for a join operation. This is due to how we store related data in table groups hierarchically. Second, group_indexes can be created on top of a table group. This means that indexes can be created on columns from more than 1 table. Third, our optimizer can choose a number of different query execution plans that use multiple indexes such as index intersection and index merging thereby reducing the amount of data that needs to be processed during various stages of query execution.
3) Do We Always Need ETL?
Why is ETL brought up as a solution when someone talks about running complex reports? Obviously in some environments, an ETL process is absolutely needed. But wouldn’t we ideally like to perform queries typically performed in data warehouse environments in real-time without the requirement for a separate process to be performed? This process is typically needed because operational systems cannot handle the load that would be generated if complex reports were run against them . Running these types of queries against an operational system would likely cripple it (this is obviously a simplification of a complex process). We’ve had many customers come to us running reports against their operational database and they don’t feel like they should need to construct a data warehouse for the relatively simple reports they wish to run on their data. We tend to agree in some cases.
Depending on who I am talking to, I either get someone really excited when I talk about this (marketing/sales people get all excited due to buzz words like ETL and real time) or am met with a groan and slight roll of the eyes (technical person who thinks I am full of shit). I can see why it comes across sounding like something a sales person would say without actually knowing what they are talking about. I do feel our message here needs to be worked on but with the release of projects like Impala from Cloudera and Spire from Drawn to Scale, I feel its clear there is huge interest for a solution in this area. Akiban can help people fighting these types of problems.
4) Augmenting Existing Deployments
Our long-term goal is to become the main database for a customer and the database of choice when a developer starts a new project, but we understand its difficult for someone who has developed an entire application with an existing database like MySQL or PostgreSQL. What we have developed to deal with this reality is so called adapters for existing systems. Our first publically available adapter is for MySQL and this allows a user to spin up a regular MySQL slave and convert whatever tables they are interested in being part of a table group to Akiban.
What Akiban is Not Good For (right now)
Now if you’ve read this far, you might be expecting me to list another problem that we solve as world hunger or something like that. We of course have some uses cases where we are not suitable and some drawbacks. So let’s balance the 4 problems I feel Akiban solves with 4 reasons why you might be reluctant to use Akiban at this present time.
1) Scale out is coming, but not here yet.
Today Akiban is focused on single node performance but with an eye to developing scale out functionality in the near future. Our scale out capability is under development but it is not expected to be production ready until next year.
This assumes you want to deploy Akiban as your main database. If you are deploying Akiban as a MySQL replica in an existing MySQL environment, there is no reason multiple MySQL slaves with Akiban cannot be spun up.
2) Simple Queries or No Problems
If your application really only issues simple queries and does not use an ORM, then Akiban is not really a fit. I would be surprised if someone with such a workload would be experiencing problems.
If your existing solution is working just fine for you, why change? You would be surprised at the number of customers we talk to who really have no need for our solution since they have no problems or are unlikely to have any need for Akiban in the near future. We are of course happy to work with these customers but we tell them straight up that they probably don’t need Akiban.
Obviously many of the existing relational databases on the market today have a head start on us here (PostgreSQL by almost 30 years). If you are looking for a database solution that has been around for a long time and deployed countless times, Akiban may not be what you are looking for. I will add though that we have a few customers where we have been deployed for almost a year (public customer testimonials coming in the next few weeks all going well).
However, I will say that this is another reason why we are working on adapters for other database systems. If you are not comfortable trying out a new database like Akiban, spinning it up as a slave in your staging/development environment for testing purposes is a pretty low risk and will not affect any existing infrastructure.
4) Existing knowledge
This leads on from point (4) above. If you have built a large infrastructure on another database, its likely your staff is highly skilled in that database platform. While Akiban is quite easy to use and administer, as with other database systems, some knowledge of Akiban needs to be gained in order to use the system in the best manner possible. Also since Akiban is a new solution, not as much troubleshooting information is available publicly. For example, when encountering an issue in MySQL, a simple Google search is likely to result in being led to a page where someone else has documented a resolution for the issue.
This post was an honest attempt at stating what I personally think Akiban is a great solution for and what we are currently not a good fit for. My personal opinion (obviously biased since I work for Akiban) is that the problems we are solving far outweigh the drawbacks of our solution. We will have a scale out strategy in less than a year which is obviously important and you can be sure I will be blogging about that as we develop it. I’d also like to mention that points (3) and (4) that are dis-advantages of Akiban apply to any database solution that is relatively new and so is not unique to Akiban.
Input on what we are doing at Akiban is very important to us. If you have any comments that you would like to add, please leave them here or ask on our public mailing list. Also, if you are curious to try the product out, it can be downloaded for free here.
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