Archive Queries Best Practices

To improve the success of Archive queries consider the following recommendations:

• Write conditions on indexed fields. The complexity of the SOQL query has an enormous influence on whether a field is suitable for indexing. Standard and custom indexes are different. Read more here.
• Reference the SystemModstamp rather than the LastModifiedDate. Read more here.
• Consider that Force.com has its own SOQL query optimizer. Read more here.