Hi folks,
A customer of mine has an Oracle DB on Sun Solaris coming out from a conversion from DB2 on OS/390.
The Sun people performed the conversion on a "one to one" base, without seeking for any optimizing goal.
So I have a very huge table, which could be also partitioned, with 5 big indexes on her.
This indexes are equipotential ... meaning each of them has the same number of rows of the table ... so they are pratically five PK indexes.
I was looking the I/O for each datafile and I saw writes are 5 times the reads for the datafile holding those indexes.
To me this sounds like:
- Nobody uses these indexes for search
- These indexes are only accessed to be kept updated from Oracle, because I believe Oracle needs to read a leaf of an index in order to change the value of this leaf
Do you think I am right?
Do you have any suggestions?
A customer of mine has an Oracle DB on Sun Solaris coming out from a conversion from DB2 on OS/390.
The Sun people performed the conversion on a "one to one" base, without seeking for any optimizing goal.
So I have a very huge table, which could be also partitioned, with 5 big indexes on her.
This indexes are equipotential ... meaning each of them has the same number of rows of the table ... so they are pratically five PK indexes.
I was looking the I/O for each datafile and I saw writes are 5 times the reads for the datafile holding those indexes.
To me this sounds like:
- Nobody uses these indexes for search
- These indexes are only accessed to be kept updated from Oracle, because I believe Oracle needs to read a leaf of an index in order to change the value of this leaf
Do you think I am right?
Do you have any suggestions?
