[OSM-dev] Slippy Map, automatic Tile Rendering

Robert (Jamie) Munro rjmunro at arjam.net
Thu Jan 18 23:11:34 GMT 2007


Andreas Brauchli wrote:
> On Thu, 2007-01-18 at 19:18 +0100, Raphaël Jacquot wrote:
>> Hakan Tandogan wrote:
>>
>>> Another idea: build a trigger that computes the tile number (for each 
>>> different renderer, if multiple projections are used) and sets a flag 
>>> for that tile on each insert/update/delete for a certain point / way / 
>>> whatever.
>>
>> thing is, I'm not sure mysql has those *g*
> 
> CREATE TRIGGER was added in MySQL 5.0.2
> http://dev.mysql.com/doc/refman/5.1/en/create-trigger.html

And MySQL begins to approach where other databases were many years ago. :-)

We should still move to PostgreSQL because it doesn't lock tables
against reading ever, and all the features like triggers and referential
integrity are mature, and mostly designed in from the beginning not
bolted on later. You don't have to decide which type of table to use
because they have only made one type of table and it's good in all
cases, so there's not been a need to develop alternatives. The SQL
syntax is standard.

Yes, I know, we are not going to move until we have some performance
measurements. This is really just a plea to not go developing lots of
MySQL triggers and make it harder to move later. :-)

Robert (Jamie) Munro

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