Abstract: Methods, systems, and products are provided for code path tracking. Embodiments include identifying an instrumented trace point in software code to be path tracked; identifying a function executed at the instrumented trace point in the software code; identifying parameters for the function executed at the instrumented trace point; and recording a description of the function, the parameters, and the result of the execution of the function using the parameters.

Abstract: A system and method of creating an access plan for a database query is disclosed. The system and method include identifying a first portion of a column of a table of a database. The first portion of the column may be in a select statement of the database query. The system and method include estimating a first statistical value for the column. The estimating may occur by analyzing a second portion of the column. The system and method include generating the access plan to predict a characteristic of a set of results for the database query. In generating the access plan, the first statistical value for the column may be used.

Abstract: A system and method of creating an access plan for a database query is disclosed. The system and method include identifying a first portion of a column of a table of a database. The first portion of the column may be in a select statement of the database query. The system and method include estimating a first statistical value for the column. The estimating may occur by analyzing a second portion of the column. The system and method include generating the access plan to predict a characteristic of a set of results for the database query. In generating the access plan, the first statistical value for the column may be used.

Abstract: Embodiments of the invention provide techniques for optimizing database queries for energy efficiency. In general, a query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. In one embodiment, the query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: A system and method of creating an access plan for a database query is disclosed. The system and method include identifying a first portion of a column of a table of a database. The first portion of the column may be in a select statement of the database query. The system and method include estimating a first statistical value for the column. The estimating may occur by analyzing a second portion of the column. The system and method include generating the access plan to predict a characteristic of a set of results for the database query. In generating the access plan, the first statistical value for the column may be used.

Abstract: A system and method of creating an access plan for a database query is disclosed. The system and method include identifying a first portion of a column of a table of a database. The first portion of the column may be in a select statement of the database query. The system and method include estimating a first statistical value for the column. The estimating may occur by analyzing a second portion of the column. The system and method include generating the access plan to predict a characteristic of a set of results for the database query. In generating the access plan, the first statistical value for the column may be used.

Abstract: In an embodiment, a recursive query is received that comprises a first select statement with a seed select statement and a second select statement with a recursive reference, wherein the recursive query further identifies at least two columns in at least one table, wherein the at least two columns have parent-child relationships represented by nodes in a graph, wherein the graph represents the organization of values in rows in the at least one table. A target recursion depth is calculated for the graph based on a fanout of the graph. In an embodiment, the target recursion depth is calculated by summing the fanout at each recursion depth of the graph multiplied by a number of nodes at each recursion depth of the graph. An estimated number of rows that the recursive query will return is estimated based on the target recursion depth.

Abstract: In an embodiment, a recursive query is received that comprises a first select statement with a seed select statement and a second select statement with a recursive reference, wherein the recursive query further identifies at least two columns in at least one table, wherein the at least two columns have parent-child relationships represented by nodes in a graph, wherein the graph represents the organization of values in rows in the at least one table. A target recursion depth is calculated for the graph based on a fanout of the graph. In an embodiment, the target recursion depth is calculated by summing the fanout at each recursion depth of the graph multiplied by a number of nodes at each recursion depth of the graph. An estimated number of rows that the recursive query will return is estimated based on the target recursion depth.

Abstract: In an embodiment, a recursive query is received that comprises a first select statement with a seed select statement and a second select statement with a recursive reference, wherein the recursive query further identifies at least two columns in at least one table, wherein the at least two columns have parent-child relationships represented by nodes in a graph, wherein the graph represents the organization of values in rows in the at least one table. A target recursion depth is calculated for the graph based on a fanout of the graph. In an embodiment, the target recursion depth is calculated by summing the fanout at each recursion depth of the graph multiplied by a number of nodes at each recursion depth of the graph. An estimated number of rows that the recursive query will return is estimated based on the target recursion depth.

Abstract: Embodiments of the invention provide techniques for optimizing database queries for energy efficiency. In general, a query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. In one embodiment, the query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: Methods, systems, and products are provided for code path tracking. Embodiments include identifying an instrumented trace point in software code to be path tracked; identifying a function executed at the instrumented trace point in the software code; identifying parameters for the function executed at the instrumented trace point; and recording a description of the function, the parameters, and the result of the execution of the function using the parameters.

Abstract: Methods, systems, and products are provided for code path tracking. Embodiments include identifying an instrumented trace point in software code to be path tracked; identifying a function executed at the instrumented trace point in the software code; identifying parameters for the function executed at the instrumented trace point; and recording a description of the function, the parameters, and the result of the execution of the function using the parameters.

Abstract: Techniques for optimizing database queries for energy efficiency. A query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. The query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: A plan for executing a query in a relational database is obtained. A query for accessing data in the relational database is received. The query specifies N tables in the relational database from which data is to be retrieved. A determination is made whether a syntax of the query matches a syntax of a plan in a plan cache for executing the query. Matches are identified between generic table formats of the N tables specified in the query to generic table formats of N tables specified in the plan responsive to the syntax of the query matching the syntax of a plan in the plan cache for executing the query. The plan for executing the query is obtained based on whether the syntax of the query matches the syntax of the plan and based on identified matches between the generic table formats of the N tables specified in the query to the generic table formats of the N tables specified in the plan.

Abstract: Embodiments of the invention provide techniques for optimizing database queries for energy efficiency. In general, a query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. In one embodiment, the query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: Embodiments of the invention provide techniques for optimizing database queries for energy efficiency. In general, a query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. In one embodiment, the query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: Embodiments of the invention provide techniques for optimizing database queries for energy efficiency. In general, a query optimizer is configured to compare energy requirements of query plans, and to select a query plan requiring minimal energy to execute. In one embodiment, the query optimizer may also compare time performance of the query plans, and may select a query plan by matching to a user preference for a relative priority between energy requirements and time performance.

Abstract: A plan for executing a query in a relational database is obtained. A query for accessing data in the relational database is received. The query specifies N tables in the relational database from which data is to be retrieved. A determination is made whether a syntax of the query matches a syntax of a plan in a plan cache for executing the query. Matches are identified between generic table formats of the N tables specified in the query to generic table formats of N tables specified in the plan responsive to the syntax of the query matching the syntax of a plan in the plan cache for executing the query. The plan for executing the query is obtained based on whether the syntax of the query matches the syntax of the plan and based on identified matches between the generic table formats of the N tables specified in the query to the generic table formats of the N tables specified in the plan.

Abstract: A method, system, and computer program product for user-driven targeted query re-optimizations using delta values are provided. The method includes displaying a query tree for a query via a graphical user interface (GUI), where the query tree includes a plurality of interconnected nodes in a tree structure, and outputting a delta value as a difference between an estimated and an actual performance metric of query execution. The method also includes receiving a request to provide alternative execution plans for a subtree of a selected node of the query tree, and displaying at least one alternative execution plan description for the subtree of the selected node. The method further includes receiving a re-optimization request for a user selected alternative execution plan description, and displaying a re-optimized query tree resulting from the re-optimization request.

Abstract: Methods, apparatus, and products are disclosed for caching an access plan for a query that include: receiving, in a SQL module of a DBMS, a SQL query that specifies data for retrieval from a database, the database characterized by database statistics, the SQL query characterized by one or more host variable values; generating, by the SQL module, an access plan in dependence upon the SQL query; calculating, by the SQL module, a routing code for the SQL query in dependence upon the host variable values of the SQL query and a portion of the database statistics; and storing, by the SQL module, the access plan in an access plan cache, including associating with the access plan the routing code for the SQL query and the portion of the database statistics used to calculate the routing code.