Thunderstone Support Forums

We are experimenting replacing some varchar fields with blobs to reduce table size. Figure it will improve performance on counts.

But performance seems slower if the table has been updated without being indexed.

Should we refresh Metamorph indexes more frequently if we're using a lot of blob fields? Is the performance penalty for blobs high if your indexes are not fully caught up?

Blob fields are most useful when you rarely access them. If you're selecting the blob field you're actually causing more seeking and reading than for non-blob. So an out of date index will cause more disk activity if the query includes the blob field.