On 01/26/2015 02:56 PM, Sawada Masahiko wrote:
> Hi,
>
> Attached patch fixes the typo in guc.c.
> It's typo, I think.
>
> diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
> index f6df077..f4f1965 100644
> --- a/src/backend/utils/misc/guc.c
> +++ b/src/backend/utils/misc/guc.c
> @@ -3880,7 +3880,7 @@ build_guc_variables(void)
> }
>
> /*
> - * Create table with 20% slack
> + * Create table with 25% slack
> */
> size_vars = num_vars + num_vars / 4;
No, I think that's intentional. After the creation, indeed 20% of the
table is empty. For example, if num_vars is 100, size_vars is 125. And
100/125 = 0.80.
In add_guc_variable, where the table is enlarged, it says:
> /*
> * Increase the vector by 25%
> */
> int size_vars = size_guc_variables + size_guc_variables / 4;
That's correct too. The table is enlarged by 25%, so after the
operation, 20% of it is again free. Subtle ;-)
(Although I don't think "increase" is the correct term here. Should be
"enlarge", or "increase the *size* of the vector by 25%".)
- Heikki
