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Date: Mon, 31 Aug 2020 09:19:48 +0200
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Subject: Re: [PHP-DEV] PDO fetch performance problems with many bindparameters
From: cmbecker69@gmx.de ("Christoph M. Becker")

On 29.08.2020 at 09:30, Matteo Beccati wrote:

> Hi Christoph,
>
> On 28/08/2020 22:57, Christoph M. Becker wrote:
>> Can we be certain that the relevant bits of the formerly _reserved_flag=
s
>> are zero-filled for all existing drivers?
>
> We can, that's basically the premise of the PR itself:
>
>  1. The flags are in the pdo_dbh_t struct which is the dbh->inner part
>  2. dbh->inner =3D ecalloc(1, sizeof(pdo_dbh_t)):
>  3. stmt->dbh is set as dbh->inner, in prepare and query
>  4. drivers can eventually set some bits to 1.
>
> A few quick links:
>
> https://github.com/php/php-src/blob/658f6ff2dae42c4f2b5c6f8d6adc8c8f09b5=
2b47/ext/pdo/php_pdo_driver.h#L514
> https://github.com/php/php-src/blob/658f6ff2dae42c4f2b5c6f8d6adc8c8f09b5=
2b47/ext/pdo/pdo_dbh.c#L562
> https://github.com/php/php-src/blob/658f6ff2dae42c4f2b5c6f8d6adc8c8f09b5=
2b47/ext/pdo/pdo_dbh.c#L1085
> https://github.com/php/php-src/blob/658f6ff2dae42c4f2b5c6f8d6adc8c8f09b5=
2b47/ext/pdo/pdo_dbh.c#L1481

Thanks!  So there only would be a problem, if a driver modifies
_reserved_flags (what they're not supposed to do).  Looks to be okay
then for the stable release branches.

=2D-
Christoph M. Becker