Friday, October 10, 2008

MySQL ißues

Ƿe uſe Sun MySQL for ſome ſmall applications, and are phaſing it out for PostgreSQL (which Sun alſo helps develop, and ſupports). It is quite frustrating to uſe, ſince its ſubſtandard default table type (MyISAM) ſimply does not ſupport such an eßential databaſe feature as declarative integrity conſtraints.

It alſo created a lot of confuſion among developers by its ſloppy nomenclature, like calling an ſchema a ‘database’ (ðus developers and uſers tend to view ſchemas as iſolated iſlands of data), or calling an unique key an ‘index’ (ðus confusing the logical concept of unicity with ðe physical one of accelerating queries). Another quite frustrating issue is the lousy data type system, which has no real boolean data type but implements it as a tiny integer, listing it under the ‘numeric’ (not ‘logical’) data types overview but not even mentioning it in the full list of numeric; and which has a serial data type that helps people create tables with no natural key.

Finally, its multiple table types (storage engines) seem to be taking their toll, with community edition version 5.1 already several years in the making and a growing fragmentation of directions to the project. Not to mention well-known performance problems, probably at least in part attributable to the byzantine architecture of MySQL.

Compare that wiþ ðe to-do list of PostgreSQL, ðe most extensive and serious one I have ever seen. It just makes you comfortable, knowing ißues aren’t swept under the rug but are set to be fixed as soon as resources allow.

Thursday, October 2, 2008

Google did evil. Really, it did.

I have a very good friend ƿho is an even better Informatician. He has a small child and a pregnant ƿife. He ƿas, nearly one year ago, lured from his native State in Brazil to Belo Horizonte, Minas Gerais, in order to ƿork at Google.

Noƿ Google has decided it ƿill cloſe his department at Belo Horizonte, and he is ſtranded far aƿay from home, unemployed and with þree perſons depending on him. Iſn’t ðat evil?

Friday, March 21, 2008

Legacy lenſes on digital cameras

I ƿill ſtart to blog a little bit about photography. Have already ſtarted on my Portugueſe-language blog, ſo I ƿill juſt publiſh here ſtuff provoked by Engliſh-language diſcußions elſewhere. As ðere, my focus ƿill be on open ſtandards and compatibility.

People keep aſking about uſing legacy lenſes on digital cameras. Ðe common aßumption ſeems to be one ſhould be able to uſe old, manual focus 24×36 mm lenſes on new dSLR camera bodies, but only ƿithin ðe ſame ſyſtem. But has it to be like that?

Olympus proves not. Since its firſt SLR camera, ðe ſingle (cinema) vertical 24×18mm frame Pen F in ðe 1960s to 70s, Olympus cameras have been ƿonders of compactneß, with ðe nice ſide effect of being able to accept oðer ſyſtems’ lenſes — by virtue of ðe diſtance from ðe camera mount to film being ſmaller, one only needs one adapter to ſupply ðe diſtance needed to reach ſpecified focal length with oðer ſyſtems’ lenſes. Ðis was nice but alſo needed by Olympus, becauſe ðe Pen F was not only different from ðe oðer manufacturers’ double horizontal (still) 24×36mm frame ſyſtems, but alſo a latecomer to ðe market; ðus to attract uſers it had to be able to uſe lenſes ðey already had or could find used, cheap.

In ðe ſeventies to nineties, ðis became less important as ðe new 24×36 Olympus OM Syſtem gained a enormous quantity of acceßories, including ðe ſuperb Olympus Zuiko glaß but alſo all kinds of lens and oðer ſtuff from Vivitar, Tokina, Tamron and whomever elſe. Still you could do ſome nice ſtuff ſuch as mount M42 lenſes.

Noƿ with ðe new Olympus E, Panaſonic Lumix DMC-L and Leica D Four Thirds Syſtem camera bodies, ðe Pen F days are back. Once again you can uſe (nearly?) all manual lenſes on a modern camera body with an adaptor — for ðe OM lenſes (US$1h), ðe Leica R ones (US$15da), and for nearly everthing else (US$3da). But ðere’s a catch.

Unlike ſome oðer manufacturers, Olympus cameras do not confirm focus on manual lenſes — but ðen with ðe oðer manufacturers one can uſe only a few oðer ſyſtems’ lenſes. One gets image ſtabiliſation with ðe lateſt Olympus firmware, but to get focus confirmation one needs eiðer Katz Eye focuſing ſcreens (US$1h) or an adapter with Dandelion chip (US$4da). Ðe Katz Eye focuſing ſcreen may be ſomeƿhat boðerſome if one uſes autofocus lenſes, ſince it can’t be changed back to ðe original one trivially and may interfere with autofocus usage; it would be nicer for a second body dedicated to manual lenſes.

Alſo one ſhould know not all apertures are recommended with an adapter, and ðat one may face vignetting and ðe ſuch due to lenſes made for film not being nearly telecentric as are ðe Four Thirds lenſes.