>CRM_DOCUMENT_HEADER Table - PK_DOCUMENT_HEADER is primary key and having seperate index on this column as well

What do you mean by this, Vishal?

I think it was fixed a while ago, but duplicate indexes used to confuse the optimizer, so PK_DOCUMENT_HEADER ought not to be both the primary key and have a separate single-field index (unless the PK or index is DESCENDING or consists of more than one field) - at best it makes INSERTs marginally slower due to having to maintain two identical indexes.

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