On Sun, Feb 16, 2020 at 9:12 AM MythTV <noreply@mythtv.org> wrote:
> #13517: Reducing memory usage by mythfilldatabase to 1/6 of original usage
> ---------------------------------------+-------------------------------
> Reporter: Hans Dingemans | Owner: Peter Bennett
> Type: Patch - Feature | Status: assigned
> Priority: minor | Milestone: needs_triage
> Component: MythTV - Mythfilldatabase | Version: Master Head
> Severity: medium | Resolution:
> Keywords: | Ticket locked: 0
> ---------------------------------------+-------------------------------
>
> Comment (by Peter Bennett):
>
> Gary - thank you for your valuable input.
>
> Hans -
> Regarding using database rollback - MythTV uses autocommit throughout, so
> I don't think that is an option.
>
That won't be a problem; from the MYSQL manual:
To disable autocommit mode implicitly for a single series of statements,
use the START TRANSACTION statement:
With START TRANSACTION, autocommit remains *disabled until you end the
transaction with COMMIT or ROLLBACK.* The autocommit mode then reverts to
its previous state.
> Does the system complete parsing before updating the database?
Yes.
> If so it
> should be easy to reject the whole run if there is an error.
>
Yes this patch it does that already; however, I'll test a few of the cases
Gary described, and come back to you, because I am not sure if the XML
syntax checking is as accurate with QXmlStreamReader as it is with
XDomDocument; I guess only the library maintainers know for sure :-)
>
> When updating the database does it first delete old data? If so it would
> be dangerous to accept a half complete run because the program data may be
> deleted and not replaced.
>
> --
> Ticket URL: <https://code.mythtv.org/trac/ticket/13517#comment:11>
> MythTV <http://www.mythtv.org>
> MythTV Media Center
>
Greetings, Hans.
> #13517: Reducing memory usage by mythfilldatabase to 1/6 of original usage
> ---------------------------------------+-------------------------------
> Reporter: Hans Dingemans | Owner: Peter Bennett
> Type: Patch - Feature | Status: assigned
> Priority: minor | Milestone: needs_triage
> Component: MythTV - Mythfilldatabase | Version: Master Head
> Severity: medium | Resolution:
> Keywords: | Ticket locked: 0
> ---------------------------------------+-------------------------------
>
> Comment (by Peter Bennett):
>
> Gary - thank you for your valuable input.
>
> Hans -
> Regarding using database rollback - MythTV uses autocommit throughout, so
> I don't think that is an option.
>
That won't be a problem; from the MYSQL manual:
To disable autocommit mode implicitly for a single series of statements,
use the START TRANSACTION statement:
With START TRANSACTION, autocommit remains *disabled until you end the
transaction with COMMIT or ROLLBACK.* The autocommit mode then reverts to
its previous state.
> Does the system complete parsing before updating the database?
Yes.
> If so it
> should be easy to reject the whole run if there is an error.
>
Yes this patch it does that already; however, I'll test a few of the cases
Gary described, and come back to you, because I am not sure if the XML
syntax checking is as accurate with QXmlStreamReader as it is with
XDomDocument; I guess only the library maintainers know for sure :-)
>
> When updating the database does it first delete old data? If so it would
> be dangerous to accept a half complete run because the program data may be
> deleted and not replaced.
>
> --
> Ticket URL: <https://code.mythtv.org/trac/ticket/13517#comment:11>
> MythTV <http://www.mythtv.org>
> MythTV Media Center
>
Greetings, Hans.