MDB and SQLite
19, Mar, 2012Howard Chu just sent out a note to the OpenLDAP Developer email list. We thought some of you might be interested.
I’ll be presenting some more details at the UKUUG LISA conference in Edinburgh in 2 days. Just a quick note here…
SQLite 3.7.7.1 (unmodified) took ~22.43 seconds to insert 1000 randomly-ordered records on my laptop (with Samsung SSD). The SQLite modified to use MDB took only 1.06 seconds.
This 20:1 improvement in write performance is most significant in terms of absolute efficiency. Given how pervasively SQLite is used in Android and apps like Firefox, on smartphones, tablets, and other battery-powered devices, there’s a potential to significantly increase the runtimes of these devices by switching to SQLite+MDB.
Read efficiency is somewhat of a lost cause, >95% of the CPU time in reads is spent in the SQL parser. Even though MDB is much more efficient at reads than stock SQLite, the difference is lost in the noise under the parser overhead.
I believe, for the vast majority of situations where SQLite is embedded in applications, significant efficiency gains would be obtained by using a pure binary data interface. While a simple key-value interface may be too primitive for app convenience, an inline implementation of the X.500 data model (with indexing) may be more useful. I.e., slapd back-mdb turned into an application library.
- Posted by Symas in in
Phony Security Scare-Tactics
10, Mar, 2012We noticed this gem via Slashdot: Measuring China‘s Cyberwar Threat. It followed a similar entry from John Robb’s Global Guerrillas blog call You don‘t need a cyber attack to take down the north american power grid. We agree with John and take issue with the premise supported by the Network World article and the work it pointed at.
First, and probably most important, Symas Corporation’s Web site was the subject of several PHP code injections that eventually took our site down. We were “hacked” and “hacked off.” The hacks cost us a person week of recovery and we still haven’t recovered all the blog data that’s stuck in a couple of MySQL databases we haven’t decoded yet.
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Too Successful?
8, Mar, 2012We use a desktop sharing provider/meeting manager owned by a large router company. The monthly fee was kind of steep for us at the time we started with them, so for a long time we only had one account and shared it. Well now, thanks to our customers and a *lot* of hard work on our part, we can justify more than one account. I thought
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Welcome
29, Feb, 2012Our former blog(s) got caught up in some security/hosting issues and need to be recovered. For those of you with this address bookmarked, we felt we ought to get something up as we clawed our way back on-line.
For the curious: Symas is doing well. back-mdb is getting shaken down and a lot of rather serious attention went into syncrepl to address some lingering issues. delta syncrepl, an enhancement that lets you reduce network traffic at the expense of local processing cycles, is reportedly doing well in at least one enterprise. 2012 is off to a pretty decent start.
- Posted by Symas in in