stefan@extum.com writes:
But anyway this is not so important, but why upper cases are bad ?
It's well established that all-lower-case text is more readable than
all-upper-case ... at least in English; but I think the same would be
true of any language using an approximately Roman alphabet. The problem
with upper case is there's less variation in the overall letter shape.
If you don't care to dig in the academic literature about it, here's a
simple experiment: which of the following paragraphs do you find more
readable?
it's well established that all-lower-case text is more readable
than all-upper-case ... at least in english; but i think the
same would be true of any language using an approximately roman
alphabet. the problem with upper case is there's less variation
in the overall letter shape. if you don't care to dig in the
academic literature about it, here's a simple experiment: which
of the following paragraphs do you find more readable?
IT'S WELL ESTABLISHED THAT ALL-LOWER-CASE TEXT IS MORE READABLE
THAN ALL-UPPER-CASE ... AT LEAST IN ENGLISH; BUT I THINK THE
SAME WOULD BE TRUE OF ANY LANGUAGE USING AN APPROXIMATELY ROMAN
ALPHABET. THE PROBLEM WITH UPPER CASE IS THERE'S LESS VARIATION
IN THE OVERALL LETTER SHAPE. IF YOU DON'T CARE TO DIG IN THE
ACADEMIC LITERATURE ABOUT IT, HERE'S A SIMPLE EXPERIMENT: WHICH
OF THE FOLLOWING PARAGRAPHS DO YOU FIND MORE READABLE?
For me, at least, the second version takes noticeably more time to read
and is certainly less pleasant. (I suppose that for a non-native
speaker of English, mental translation might slow you down to the point
where you don't notice a difference. If so, try it on a random
paragraph in your own language.)
It's a pattern recognition issue. Taken in context with your reading experience
and the general constructs of the English language in addition common usage,
you encounter far more lower case letters than upper case letters. It makes
sense that it would be easier to recognize the words in all lower case.
Secondly, your brain expects lower case letters behind the leading upper
case letter for the word. So in a sense you backtrack just a little because
it doesn't match what you expect. I'm not discounting the statements you
made, but this is one additional observation.
For PostgreSQL there is also a backwards compatibility issue: if we
change this decision now, we'd cause all kinds of problems for existing
code and databases.
Why then Oracle , IBM is using them and why the SQL standard is not
changed ?
The SQL standard's choice in this matter is prehistoric; undoubtedly
it falls out of the days when computer printers only had one type case.
IBM probably still has a residual fondness for those days ;-). But
the rest of the industry figured out that lower case was better
somewhere around 1960, cf Algol-60 which was the first language to spell
its keywords preferentially in lower case.
regards, tom lane
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