● A Relational Model of Data for Large Shared Data Banks (E.F. Codd, 1970)
1.2. Data Dependencies in Present Systems
provison; < provide (make available for use)
facilitate; make easy or easier
impair; weaken or damage
However, the variety of data representation characteristics which can be changed
without logically impairing some application programs is still quite limited.
データ (の記述) と プログラム とが 今なお 論理的に切り離されていない、ということ。
interact; act so as to affect each other
clutter; (often foll. by up, with) fill a space in a disorderly way
property; an attribute, quality, or characteristic
Further, the model of data with which users interact is still cluttered with representational properties, particularly in regard to the representation of collections of data (as opposed to individual items).
1. users interact with the model of data
↓
2. the model of data is still cluttered with representational properties
↑
3. the representation of collections of data (as opposed to individual items)
集合としての データ・モデル が 今なお 整えられていない、ということ。
1.2.1. Ordering Dependence.
hardware-determined ordering of addresses; RRN (Relatinal Record Numer) のこと。
(類) implemented by means of pointers
assume; accept as true without proof; take (responsibility or control)
Such systems normally permit application programs to assume that the order of presentation of records from such a file is identical to (or is a subordering of) the stored ordering.
レコード の表示順がそれらの格納順と同じ (あるいは、それに準ずる順) である事がそういう システム では普通である、ということ。the stored ordering は、native file format のこと。
take advantage of; 1 make unfair use of for one's own benefit.
2 make good use of the opportunities offered.
for some reason;
you mean that you know it happened or is true, but you do not know why.
single out; choose (someone or something) from a group for special treatment.
distinction; a noticeable difference or contrast
fail to make a clear distinction between order of presentation on the hand and stored ordering on the other.
表示順と格納順は まったく noticeably different である、ということ。