In Query optimization, Estimation of plan cost is based on:Select one:a.Statistics estimation for intermediate results to compute cost of complex expressionsb.All of the abovec.Cost formulae for algorithms, computed using statisticsd.Statistical information about relations

cost-based query optimization consist ofSelect one:a.Annotate resultant expressions to get alternative query plansb.All of the abovec.Generating logically equivalent expressions using equivalence rulesd.Choose the cheapest plan based on estimated cost

A query execution plan provides crucial assistance for query optimization by showing the following elements:Select THREE.A. Join typeB. Alternative (more suitable) join conditionC. Estimated query costD. NO STATISTICS indicator

What is TRUE about Query Optimization?Select one:a. All of the aboveb.The cost of evaluating a query can vary depending on its type.c.The evaluation plan is built by the system, so the user need not focus on writing their query efficiently.d.An efficient query evaluation plan is generated by a database system, which minimizes its costs.

You are comparing two query execution plans.Query plan A has an estimated query cost of 1000Query plan B has an estimated query cost of 500What can we conclude from this?A.Query B will take 50% less time to execute than query AB.Query B is more efficient but that has no impact on query execution timeC.Query A is less efficient and most likely slower than a query B.

One of the objectives in facility location analysis is to select a site with the lowest total cost. Which of the following costs are hidden costs that should be included in the analysis?Question 41Answera.Bribery costsb.Taxesc.Construction costsd.Infrastructure costse.Movement of preproduction material between locations