Re: RE : full featured alter table?

Added to TODO:

   o Allow columns to be reordered using ALTER ... POSITION i col1 [,col2];
     have SELECT * and INSERT honor such ordering



---------------------------------------------------------------------------

Tom Lane wrote:
> =?ISO-8859-1?Q?Sven_K=F6hler?= <skoehler@upb.de> writes:
> > perhaps we could also think about a
> > ALTER TABLE <table> POSITIONS <column1>,<column2>,...
>
> You could invent a syntax that supports both use cases, along the lines
> of
>
> ALTER ... POSITION <i> <column1> [ , <column2> ... ]
>
> with the meaning that the named columns are inserted sequentially between
> positions i-1 and i, moving them from wherever they were, and leaving
> all not-mentioned columns in their existing relative order.  This
> degenerates to the same as your first proposal if one column is named,
> and at the other extreme allows all the columns to be re-ordered in one
> command.
>
> It could get a little confusing if some of the named columns previously
> occupied positions less than <i>.  I'd suggest the following
> more-concrete specification:
>
> 1. <i> must be in the range 1 to (<number of columns in table> -
>    <number of columns named in statement> + 1).
> 2. After the ALTER, the named columns have ordinal positions <i>, <i+1>,
>    etc.
> 3. Any columns not named are placed into the remaining slots (1..i-1
>    and i+nnamedcols..ntablecols) in the same relative order they had
>    before.
>
>             regards, tom lane
>
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