Aggregate table and outdated rows

Question

hi everybody,
let´s assume the following scenario:
- one fact table, one aggregator, one target aggregate table with a sum column.
- aggregate table loading type is set to "insert/update", update matching is done on several columns.
- first load is started, aggregated data is correct, no problems so far
- one column is updated in the fact table (all rows)
- now we´ve got a new attribute set which doesn´t match a row at the aggregate table, so a new row is inserted
- the aggregate table now contains two rows, but only one is valid
how can i avoid this without truncating the aggregate table before loading? do i have to delete outdated aggregate rows before/after loading, or is there any other solution?
thanks for your help,
peter
Edited by: peter_AT on Nov 12, 2009 7:46 AM

Answer 1

>
Why can't you just update that collumn in your target table if you don't need the previous version of that row?
>
thanks for your suggestion.
but this can cause "ORA-30926: unable to get a stable set of rows in the source tables" - or am i wrong about this?
a more detailed explanation:
fact table t_src:
SQL> select * from t_src;
S1  S2
A   Bproperty "match column when updating row" on columns a1 and a2 of aggregation table t_agg are set to "Yes".
aggregate table t_agg contains these rows:
SQL> select * from t_agg;
A1  A2         NUM
A   B            1now t_src is updated:
SQL> update t_src set s1='B' where s1='A';
1 row updated.
SQL> select * from t_src;
S1  S2
B   Bafter the next load table t_agg looks like this:
SQL> select * from t_agg;
A1  A2         NUM
A   B            1
B   B            1if i want to update column A1, i have to remove matching from there - which leads to ORA-30926 when loading next time.
thanks,
peter
Edited by: peter_AT on Nov 12, 2009 7:47 AM