Thursday 18 November 2021

Be Careful with LOBs and OPTION (RECOMPILE)

Be Careful with LOBs and OPTION (RECOMPILE)

It sometimes makes sense to add OPTION (RECOMPILE) to a query. Typically this will be when:

  • A good enough plan for the query is very sensitive to one or more parameters
  • No good single value exists for the parameter to use in a hint
  • Optimize for unknown doesn’t give a good result
  • The plan might be expected to change over time
  • The cost of recompiling the statement is much less than the expected execution time
  • Recompiling every time is very likely to save more time and resources than it costs overall

All that is fairly well-known. The point of this short post is to draw your attention to another side-effect of adding OPTION (RECOMPILE) — the parameter embedding optimization (PEO).