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sql optimization

SQL: select talble1.c1
from table1,table2
where table1.c2=table2.c2

so if talbe1 has 1000 records,table2 has 100 records

the sql statement :from table1,table2 vs. from table2,table1

which sql will be more good for performance using db2?

Nov 8 '07 #1
1 1472
Ian
db*******@gmail.com wrote:
SQL: select talble1.c1
from table1,table2
where table1.c2=table2.c2

so if talbe1 has 1000 records,table2 has 100 records

the sql statement :from table1,table2 vs. from table2,table1

which sql will be more good for performance using db2?
It doesn't matter. The query-rewrite portion of the optimizer
will determine the best way (based on the tables' statistics).
If you don't have accurate statistics, the optimizer may make
a poor choice.
Nov 9 '07 #2

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