Обсуждение: Re: CREATE TABLE AS standard?

> I know I use that version my self a lot more than the SELECT INTO
> version. We probably got it 'free' from the CREATE VIEW semantics,
> as Tom suggested. I tend to use it to 'materialize' a new table when
> I'm altering schema (either denormalizing, or normalizing) and need to
> convert the type of a column. It's a little handier than seperate CREATE
> TABLE and INSERT INTO statements, although it's sematically equivalent.

I implemented CREATE TABLE AS as a semantically clearer version of
SELECT/INTO, which was (afaik) in the original Postgres95 and probably
earlier.

They are equivalent. btw, I assume that Tom used the term "abuse" in
the supportive sense of the word? :)
                   - Thomas

-- 
Thomas Lockhart                lockhart@alumni.caltech.edu
South Pasadena, California

> > I know I use that version my self a lot more than the SELECT INTO
> > version. We probably got it 'free' from the CREATE VIEW semantics,
> > as Tom suggested. I tend to use it to 'materialize' a new table when
> > I'm altering schema (either denormalizing, or normalizing) and need to
> > convert the type of a column. It's a little handier than separate CREATE
> > TABLE and INSERT INTO statements, although it's semantically equivalent.
> 
> I implemented CREATE TABLE AS as a semantically clearer version of
> SELECT/INTO, which was (afaik) in the original Postgres95 and probably
> earlier.
> 
> They are equivalent. btw, I assume that Tom used the term "abuse" in
> the supportive sense of the word? :)
> 

I covered SELECT...INTO in my book, with a short paragraph showing
CREATE TABLE...AS is equivalent.  Which one should I use in my book as
the preferred?

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> I covered SELECT...INTO in my book, with a short paragraph showing
> CREATE TABLE...AS is equivalent.  Which one should I use in my book as
> the preferred?

imho CREATE TABLE/AS should be emphasized, since SELECT/INTO hides the
fact that a table gets created, which is a fundamental operation here.
DDF vs DDL vs some other acronym etc etc.
                    - Thomas

-- 
Thomas Lockhart                lockhart@alumni.caltech.edu
South Pasadena, California