NoSQL
Discussion of the NoSQL movement, whatever that is.
WibiData, derived data, and analytic schema flexibility
My clients at Odiago, vendors of WibiData, have changed their company name simply to WibiData. Even better, they blogged with more detail as to how WibiData works, in what is essentially a follow-on to my original WibiData post last October. Among other virtues, WibiData turns out to be a poster child for my views on derived data and the corresponding schema evolution.
Interesting quotes include:
WibiData is designed to store … transactional data side-by-side with profile and other derived data attributes.
… the ability to add new ad-hoc columns to a table enables more flexible analysis: output data that is the result of one analytic pipeline is stored adjacent to its input data, meaning that you can easily use this as input to second- or third-order derived data as well.
schemas can vary over time; you can easily add a field to a record, or delete a field. … But even though you start collecting that new data, your existing analysis pipelines can treat records like they always did; programs that don’t yet know about the new cookie are still compatible with both the old records already collected, and the new records with the additional field. New programs fill in default values for old data recorded before a field was added, applying the new schema at read time.
schemas for every column are stored in a data dictionary that matches column names with their schemas, as well as human-readable descriptions of the data.
Interesting aspects of the post that don’t lend themselves as well to being excerpted include:
- How the Produce-Gather “analysis calculus” — i.e. framework — works.
- How this all ties into Apache projects (and sub-projects) such as Hadoop, HBase, and Avro.
| Categories: Data models and architecture, Data warehousing, NoSQL, Odiago and WibiData | Leave a Comment |
Couchbase update
I checked in with James Phillips for a Couchbase update, and I understand better what’s going on. In particular:
- Give or take minor tweaks, what I wrote in my August, 2010 Couchbase updates still applies.
- Couchbase now and for the foreseeable future has one product line, called Couchbase.
- Couchbase 2.0, the first version of Couchbase (the product) to use CouchDB for persistence, has slipped …
- … because more parts of CouchDB had to be rewritten for performance than Couchbase (the company) had hoped.
- Think mid-year or so for the release of Couchbase 2.0, hopefully sooner.
- In connection with the need to rewrite parts of CouchDB, Couchbase has:
- Gotten out of the single-server CouchDB business.
- Donated its proprietary single-sever CouchDB intellectual property to the Apache Foundation.
- The 150ish new customers in 2011 Couchbase brags about are real, subscription customers.
- Couchbase has 60ish people, headed to >100 over the next few months.
| Categories: Basho and Riak, Cassandra, CouchDB, Couchbase, DataStax, Market share and customer counts, MongoDB and 10gen, NoSQL, Open source, Parallelization, Web analytics, Zynga | 3 Comments |
Microsoft SQL Server 2012 and enterprise database choices in general
Microsoft is launching SQL Server 2012 on March 7. An IM chat with a reporter resulted, and went something like this.
Reporter: [Care to comment]?
CAM: SQL Server is an adequate product if you don’t mind being locked into the Microsoft stack. For example, the ColumnStore feature is very partial, given that it can’t be updated; but Oracle doesn’t have columnar storage at all.
Reporter: Is the lock-in overall worse than IBM DB2, Oracle?
CAM: Microsoft locks you into an operating system, so yes.
Reporter: Is this release something larger Oracle or IBM shops could consider as a lower-cost alternative a co-habitation scenario, in the event they’re mulling whether to buy more Oracle or IBM licenses?
CAM: If they have a strong Microsoft-stack investment already, sure. Otherwise, why?
Reporter: [How about] just cost?
CAM: DB2 works just as well to keep Oracle honest as SQL Server does, and without a major operating system commitment. For analytic databases you want an analytic DBMS or appliance anyway.
Best is to have one major vendor of OTLP/general-purpose DBMS, a web DBMS, a DBMS for disposable projects (that may be the same as one of the first two), plus however many different analytic data stores you need to get the job done.
By “web DBMS” I mean MySQL, NewSQL, or NoSQL. Actually, you might need more than one product in that area.
| Categories: Data warehousing, IBM and DB2, Microsoft and SQL*Server, Mid-range, MySQL, NoSQL, Oracle | 6 Comments |
Big data terminology and positioning
Recently, I observed that Big Data terminology is seriously broken. It is reasonable to reduce the subject to two quasi-dimensions:
- Bigness — Volume, Velocity, size
- Structure — Variety, Variability, Complexity
given that
- High-velocity “big data” problems are usually high-volume as well.*
- Variety, variability, and complexity all relate to the simply-structured/poly-structured distinction.
But the conflation should stop there.
*Low-volume/high-velocity problems are commonly referred to as “event processing” and/or “streaming”.
When people claim that bigness and structure are the same issue, they oversimplify into mush. So I think we need four pieces of terminology, reflective of a 2×2 matrix of possibilities. For want of better alternatives, my suggestions are:
- Relational big data is data of high volume that fits well into a relational DBMS.
- Multi-structured big data is data of high volume that doesn’t fit well into a relational DBMS. Alternative: Poly-structured big data.
- Conventional relational data is data of not-so-high volume that fits well into a relational DBMS. Alternatives: Ordinary/normal/smaller relational data.
- Smaller poly-structured data is data for which dynamic schema capabilities are important, but which doesn’t rise to “big data” volume.
Some big-vendor execution questions, and why they matter
When I drafted a list of key analytics-sector issues in honor of look-ahead season, the first item was “execution of various big vendors’ ambitious initiatives”. By “execute” I mean mainly:
- “Deliver products that really meet customers’ desires and needs.”
- “Successfully convince them that you’re doing so …”
- “… at an attractive overall cost.”
Vendors mentioned here are Oracle, SAP, HP, and IBM. Anybody smaller got left out due to the length of this post. Among the bigger omissions were:
- salesforce.com (multiple subjects).
- SAS HPA.
- The evolution of Hadoop.
The cool aspects of Odiago WibiData
Christophe Bisciglia and Aaron Kimball have a new company.
- It’s called Odiago, and is one of my gratifyingly more numerous tiny clients.
- Odiago’s product line is called WibiData, after the justly popular We Be Sushi restaurants.
- We’ve agreed on a split exclusive de-stealthing launch. You can read about the company/founder/investor stuff on TechCrunch. But this is the place for — well, for the tech crunch.
WibiData is designed for management of, investigative analytics on, and operational analytics on consumer internet data, the main examples of which are web site traffic and personalization and their analogues for games and/or mobile devices. The core WibiData technology, built on HBase and Hadoop,* is a data management and analytic execution layer. That’s where the secret sauce resides. Also included are:
- REST APIs for interactive access.
- Import/export tools, including JDBC access.
- Management tools.
- Analytic libraries — data mining, predictive analytics, machine learning, and so on.
The whole thing is in beta, with about three (paying) beta customers.
*And Avro and so on.
The core ideas of WibiData include:
- ALL data pertaining to a single user (or mobile device) is kept in a single, possibly very long, HBase row.
- There are two primary operators in WibiData, Produce and Gather.
- Produce operates on single rows. It can operate on one row at HBase speed (milliseconds) if you need to inform an interactive user response. Or it can operate on the whole database in batch via Hadoop MapReduce.
- It is reasonable to think of Produce as mainly doing two things. One is the aforementioned serving of data out of WibiData into interactive applications. The other is scoring, classifying, recommending, etc. on individual users (i.e. rows), in line with an analytic model.
- Gather typically operates on all your rows at once, and emits suitable input for a MapReduce Reduce step. It is reasonable to think of Gather as being a key cog in the training of analytic models.
- HBase schema management is done at the WibiData system level, not directly in applications. There’s a WibiData HBase data dictionary, powered by a set of system tables, that specifies cell data types/record types and, in effect, primitive schemas.
| Categories: Data models and architecture, HBase, Hadoop, NoSQL, Odiago and WibiData, Predictive modeling and advanced analytics, Web analytics | 11 Comments |
NoSQL notes
Last week I visited with James Phillips of Couchbase, Max Schireson and Eliot Horowitz of 10gen, and Todd Lipcon, Eric Sammer, and Omer Trajman of Cloudera. I guess it’s time for a round-up NoSQL post.
Views of the NoSQL market horse race are reasonably consistent, with perhaps some elements of “Where you stand depends upon where you sit.”
- As James tells it, NoSQL is simply a three-horse race between Couchbase, MongoDB, and Cassandra.
- Max would include HBase on the list.
- Further, Max pointed out that metrics such as job listings suggest MongoDB has the most development activity, and Couchbase/Membase/CouchDB perhaps have less.
- The Cloudera guys remarked on some serious HBase adopters.*
- Everybody I spoke with agreed that Riak had little current market presence, although some Basho guys could surely be found who’d disagree.
| Categories: Basho and Riak, Cassandra, Cloudera, Clustering, Couchbase, HBase, Market share and customer counts, MongoDB and 10gen, NoSQL, Open source, Oracle, Parallelization | 12 Comments |
Transparent relational OLTP scale-out
There’s a perception that, if you want (relatively) worry-free database scale-out, you need a non-relational/NoSQL strategy. That perception is false. In the analytic case it’s completely ridiculous, as has been demonstrated by Teradata, Vertica, Netezza, and various other MPP (Massively Parallel Processing) analytic DBMS vendors. And now it’s false for short-request/OLTP (OnLine Transaction Processing) use cases as well.
My favorite relational OLTP scale-out choice these days is the SchoonerSQL/dbShards partnership. Schooner Information Technology (SchoonerSQL) and Code Futures (dbShards) are young, small companies, but I’m not too concerned about that, because the APIs they want you to write to are just MySQL’s. The main scenarios in which I can see them failing are ones in which they are competitively leapfrogged, either by other small competitors – e.g. ScaleBase, Akiban, TokuDB, or ScaleDB — or by Oracle/MySQL itself. While that could suck for my clients Schooner and Code Futures, it would still provide users relying on MySQL scale-out with one or more good product alternatives.
Relying on non-MySQL NewSQL startups, by way of contrast, would leave me somewhat more concerned. (However, if their code is open sourced. you have at least some vendor-failure protection.) And big-vendor scale-out offerings, such as Oracle RAC or DB2 pureScale, may be more complex to deploy and administer than the MySQL and NewSQL alternatives.
| Categories: Clustering, IBM and DB2, MySQL, NoSQL, OLTP, Open source, Oracle, Parallelization, Schooner Information Technology, dbShards and CodeFutures | 2 Comments |
More notes on Oracle NoSQL
A reporter asked me for some thoughts on Oracle’s new NoSQL product. For the most part, I stand by my previous comments on Oracle NoSQL. Still, NoSQL in general deserves a place in Oracle shops, so it makes sense for Oracle to try to coopt it.
Oracle’s core DBMS is not well suited to track interactions (e.g. web clicks), even in cases where it’s the choice for transactions; it’s unnecessarily heavyweight. What’s worse, using the same database to store actions and interactions can lead to serious reliability problems. If a better architecture is to dump the clicks into some NoSQL store, massage the information, and eventually put some derived data into a relational DBMS, then Oracle will naturally try to own each step of the data pipeline.
Dynamic schemas are another area of Oracle weakness, leading in some cases to outright Oracle replacements. However, pure key-value stores go too far to the opposite extreme; you should at least be able to index and retrieve data one field at a time. Based on what I’ve seen of Oracle’s marketing literature, that feature will be missing from the first release of Oracle’s NoSQL.* Until it’s in there, and until it works well, I don’t see why anybody should use Oracle’s NoSQL product.
*Frankly, that choice makes no sense to me on any level. Yet it’s the way Oracle seems to have elected to go — or, if it isn’t, then there’s somebody writing Oracle marketing collateral who’s clearly in the wrong line of work.
| Categories: NoSQL, Oracle, Web analytics | 3 Comments |
Text data management, Part 3: Analytic and progressively enhanced
This is Part 3 of a three post series. The posts cover:
- Confusion about text data management.
- Choices for text data management (general and short-request).
- Choices for text data management (analytic).
I’ve gone on for two long posts about text data management already, but even so I’ve glossed over a major point:
Using text data commonly involves a long series of data enhancement steps.
Even before you do what we’d normally think of as “analysis”, text markup can include steps such as:
- Figure out where the words break.
- Figure out where the clauses and sentences break.
- Figure out where the paragraphs, sections, and chapters break.
- (Where necessary) map the words to similar ones — spelling correction, stemming, etc.
- Figure out which words are grammatically which parts of speech.
- Figure out which pronouns and so on refer to which other words. (Technical term: Anaphora resolution.)
- Figure out what was being said, one clause at a time.
- Figure out the emotion — or “sentiment” — associated with it.
Those processes can add up to dozens of steps. And maybe, six months down the road, you’ll think of more steps yet.
| Categories: Data warehousing, Hadoop, NoSQL, Text | 3 Comments |
