2014-03-20 9:47 GMT+01:00 Mark Kirkwood <mark.kirkw...@catalyst.net.nz>:
> On 20/03/14 20:08, Pavel Stehule wrote:
>> 2014-03-20 7:25 GMT+01:00 Mark Kirkwood <mark.kirkw...@catalyst.net.nz
>> Also I think this would probably only make sense for TEMPORARY
>> tables - otherwise you can get this sort of thing going on:
>> - you create a table and you have set a relation size limit
>> - you commit and keep working
>> - I add a whole lot of rows to your new table (taking it over the
>> - you go to add some more rows to this table...
>> you cannot to across session limit and is not important if you do
>> inserts more times or once.
> Sorry Pavel - what you have said above is difficult for me to understand -
> if the limit is intended as a *session* limit then concurrent activity from
> multiple sessions makes it behave - well - strangely to say the least, as
> tables are essentially shared resources.
I am sorry, I should to explain first our use case. Our product support
multidimensional modelling - usually we have a few (less than 1000)
unlimited user data tables. When user can to see some view (report), our
engine generate 10 - 100 queries and result of these queries are stored in
tables. Then result of one calculation can be shared between reports,
users. These tables (caches) are semi temporal - life cycle is about hour,
max days. Some queries in multidimensional analysis are Cartesian products
- we are not able to estimate well a sizes of these tables - due free
schema - users can create own logical model (users can fill these data
freely) - and variability of generated queries is too long.
So we need to some safeguards in background.