these optimizations are all fine with me, Jason Kirtland has been
handling the overhaul of MySQL reflection so maybe stop by on IRC to
compare notes.
On Jul 18, 12:57 am, Mike Bernson <[EMAIL PROTECTED]> wrote:
> I started looking to what is happen to get table information from mysql.
>
> I found that the following is issued for every table that is reflected:
>
> 2007-07-18 00:29:08,158 INFO sqlalchemy.engine.base.Engine.0x..cc show
> variables like 'character_set%%'
> 2007-07-18 00:29:08,158 INFO sqlalchemy.engine.base.Engine.0x..cc None
> 2007-07-18 00:29:08,161 INFO sqlalchemy.engine.base.Engine.0x..cc SHOW
> VARIABLES LIKE 'lower_case_table_names'
> 2007-07-18 00:29:08,161 INFO sqlalchemy.engine.base.Engine.0x..cc None
> 2007-07-18 00:29:08,163 INFO sqlalchemy.engine.base.Engine.0x..cc
> describe `company`
> 2007-07-18 00:29:08,163 INFO sqlalchemy.engine.base.Engine.0x..cc {}
> 2007-07-18 00:29:08,169 INFO sqlalchemy.engine.base.Engine.0x..cc SHOW
> CREATE TABLE `company`
>
> I have a slow connection to the database and want to min the number of
> round trips.
>
> It look like the show variables like should not be need for every table.
>
> The character_set_results is never set and should be constant for a
> given connection. so the results of of _detect_character should be
> cached at a min for the connection (I think it should also be cached
> for the host/port combo unless it get set somewhere)
>
> lower_case_table_names can only be changed on server startup. It should
> be easy to cache this query and only execute it once per host/port.
>
> The last one that can be reduce is show CREATE TABLE should have all the
> information that describe has and the reflection could happen form this
> command.
>
> I would be willing to look into getting the lower_case_table_name only
> once per server. (I hint as to where this might be cached)
>
> I think the character_set_results can also be cached on per server since
> we do set it.
> I would be willing to look into write a patch that make the reflection
> use show create table command.
>
> The first 2 should be easy and cut done the number of round trips 1/2.
>
> I do not see using the show create table as hard and that would cut the
> number of round trips per table to 1.
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalchemy@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en
-~----------~----~----~----~------~----~------~--~---
