Green Query Optimization: Taming Query Optimization Overheads through Plan Recycling
نویسندگان
چکیده
PLASTIC [1] is a recently-proposed tool to help query optimizers significantly amortize optimization overheads through a technique of plan recycling. The tool groups similar queries into clusters and uses the optimizer-generated plan for the cluster representative to execute all future queries assigned to the cluster. An earlier demo [2] had presented a basic prototype implementation of PLASTIC. We have now significantly extended the scope, useability, and efficiency of PLASTIC, by incorporating a variety of new features, including an enhanced query feature vector, variablesized clustering and a decision-tree-based query classifier. The demo of the upgraded PLASTIC tool is shown on commercial database platforms (IBM DB2 and Oracle 9i).
منابع مشابه
Efficiently approximating query optimizer plan diagrams
Given a parametrized n-dimensional SQL query template and a choice of query optimizer, a plan diagram is a color-coded pictorial enumeration of the execution plan choices of the optimizer over the query parameter space. These diagrams have proved to be a powerful metaphor for the analysis and redesign of modern optimizers, and are gaining currency in diverse industrial and academic institutions...
متن کاملParallelizing Query Optimization on Shared-Nothing Architectures
Data processing systems offer an ever increasing degree of parallelism on the levels of cores, CPUs, and processing nodes. Query optimization must exploit high degrees of parallelism in order not to gradually become the bottleneck of query evaluation. We show how to parallelize query optimization at a massive scale. We present algorithms for parallel query optimization in left-deep and bushy pl...
متن کاملStability-conscious Query Optimization
Modern query optimizers choose their execution plans primarily on a cost-minimization basis, assuming that the inputs to the costing process, such as relational selectivities, are accurate. However, in practice, these inputs are subject to considerable run-time variation relative to their compile-time estimates, often leading to poor plan choices that cause inflated response times. We present i...
متن کاملEfficient Generation of Query Optimizer Diagrams
Given a parameterized n-dimensional SQL query template and a choice of query optimizer, a plan diagram is a color-coded pictorial enumeration of the execution plan choices of the optimizer over the query parameter space. Similarly, we can define cost diagram and cardinality diagram as the pictorial enumerations of cost and cardinality estimations of the optimizer over the same space. These thre...
متن کاملOn the Production of Anorexic Plan Diagrams
A “plan diagram” is a pictorial enumeration of the execution plan choices of a database query optimizer over the relational selectivity space. We have shown recently that, for industrial-strength database engines, these diagrams are often remarkably complex and dense, with a large number of plans covering the space. However, they can often be reduced to much simpler pictures, featuring signific...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2004