Re: ALTER TABLE ADD COLUMN fast default

On 17 February 2018 at 10:46, Andrew Dunstan
<andrew.dunstan@2ndquadrant.com> wrote:
> The attached version largely fixes with the performance degradation
> that Tomas Vondra reported, replacing an O(N^2) piece of code in
> slot_getmissingattrs() by one that is O(N).

I've looked over this patch and had a play around with it.

Just a couple of things that I noticed while reading:

1. I believe "its" should be "it's" here:

+ /*
+ * Yes, and its of the by-value kind Copy in the Datum
+ */

copy does not need an upper case 'C'. There should also be a comma after "kind"

There's a similar problem with the following:

+ /*
+ * Yes, and its fixed length Copy it out and have teh Datum
+ * point to it.
+ */

there should be a comma after "length" too.

Also, "teh" ...

2. "dfferent" -> "different"

+-- Test a large sample of dfferent datatypes

I'll try to spend some time reviewing the code in detail soon.

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services