Abstract: As part of managing the loading of data from a source onto a database, according to an example, an interface through which a user is to define logic related to the loading of the data onto the database is provided. The user-defined logic pertains to at least one of a user-defined location identification of the source, a user-defined filter to be applied on the data, and a user-defined parsing operation to be performed on the data to convert the data into an appropriate format for the database. In addition, the user-defined logic is received and the user-defined logic is implemented to load the data onto the database.

Abstract: An automatic physical-layout designer for a database-management system determines the database's physical layout from a set of training queries, the database's logical design, and a parameter k that indicates how many storage nodes can be lost without losing access to any of the data. The designer lays the database out as a column store such that the stored columns constitute redundant projections on the system's different storage nodes. It repeatedly identifies a projection, whose addition to the design will result in the greatest performance improvement for the training queries. In doing so, it takes into account the different compression formats to which the different projections lend themselves. When a projection has been identified as one to be added, it is added on one node, and k projections having the same columns are added to other nodes. The designer continues thus adding projections until a space budget has been reached.

Abstract: An access structure analysis method is interspersed with the query optimization process. The method can determine the ideal combination of access structures, including both materialized views and indexes, for a given database workload. The interspersed structure analysis method can include advanced transformations like view merging, star transformation, bitmap access plans, query rewrite using materialized views, for example. The method may be performed using the query optimizer's rules as heuristics to guide the index candidate generation process.

Abstract: Methods, systems and program products for database storage. In one implementation, data of a projection of a database is stored at least partly in grouped ROS format and partly in column format based on patterns of updating the projection data. The projection data is updated so that the updated projection is stored partly in grouped ROS format and partly in column format.

Abstract: For a database query that defines a plurality of separate snowflake schemas, a query optimizer computes separately for each of the snowflake schemas a logical access plan for obtaining from that schema's tables a respective record set that includes the data requested from those tables by that query. The query optimizer also computes a logical access plan for obtaining the query's results from the record sets in which execution of the logical access plans thus computed will result.

Abstract: Computer programs encoded on a computer storage medium provide for a modular query optimizer. In one aspect, a computer program product includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a database designer and a database storage designer. In one aspect, a method includes creating a set of candidate projections and progressively narrowing the set of candidate projections and a set of queries by eliminating candidate projections that do not satisfy a performance improvement criterion for remaining queries based on the properties associated with the candidate projections.

Abstract: Computer programs encoded on a computer storage medium provide for a modular query optimizer. In one aspect, a computer program product includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for modular query optimizer. In one aspect, a method includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.

Abstract: Methods, program products and systems for determining, for a database query that does not represent a snowflake schema, a graph comprising vertices each representing a table joined in the query, a directed edge between each pair of vertices of which a first vertex represents a first table and a second vertex represents a second table that is joined in the query with the first table, each of the edges representing one of an outer join and an inner join. Further determining, for the graph, a directed spanning tree that represents an ordering of joins in the query and includes all outer join edges in the graph.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for operating on time sequences of data. In one aspect, a method includes a database management system storing and updating information in records in a table of a database, the records being associated with respective times that are spaced apart by time intervals, the database management system responding to a query that is phrased to imply a putative record with respect to a time interval that is not among the time intervals with which the records of the table are associated, and the response of the database management system to the query including a computation of a value of an attribute of the putative record from at least one non-null value of the attribute for one of the records of the table, the computation being based on an interpolation policy.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for a database designer and a database storage designer. In one aspect, a method includes creating a set of candidate projections and progressively narrowing the set of candidate projections and a set of queries by eliminating candidate projections that do not satisfy a performance improvement criterion for remaining queries based on the properties associated with the candidate projections.

Abstract: A technique for refreshing materialized views in a database is disclosed. The detail table is partitioned, and changes made to the detail table are tracked with information stored, for example. Only sections in the materialized view which correspond to the partitions which include modifications made to the detail table are refreshed, thus avoiding the need of a complete refresh to overcome staleness.

Abstract: Methods, systems and program products for database storage. In one implementation, data of a projection of a database is stored at least partly in grouped ROS format and partly in column format based on patterns of updating the projection data. The projection data is updated so that the updated projection is stored partly in grouped ROS format and partly in column format.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for modular query optimizer. In one aspect, a method includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.

Abstract: An automatic physical-layout designer for a database-management system determines the database's physical layout from a set of training queries, the database's logical design, and a parameter k that indicates how many storage nodes can be lost without losing access to any of the data. The designer lays the database out as a column store such that the stored columns constitute redundant projections on the system's different storage nodes. It repeatedly identifies a projection, whose addition to the design will result in the greatest performance improvement for the training queries. In doing so, it takes into account the different compression formats to which the different projections lend themselves. When a projection has been identified as one to be added, it is added on one node, and k projections having the same columns are added to other nodes. The designer continues thus adding projections until a space budget has been reached.

Abstract: For a database query that defines a plurality of separate snowflake schemas, a query optimizer computes separately for each of the snowflake schemas a logical access plan for obtaining from that schema's tables a respective record set that includes the data requested from those tables by that query. The query optimizer also computes a logical access plan for obtaining the query's results from the record sets in which execution of the logical access plans thus computed will result.

Abstract: Systems, methods, and media associated with function-based index tuning for queries with expressions are described. One exemplary method includes receiving a query for which an index is to be recommended. The query may include an expression, thus the method may include identifying an expression in the query and generating a set of column statistics related to the expression. The method may also include identifying candidate function-based indexes associated with the query, generating a set of function-based index statistics related to the candidate function-based indexes, and recommending a candidate function-based index.

Abstract: Systems, methods, computer-readable media and other embodiments are provided that relate to processing database queries. In one embodiment, a query analysis logic can be configured to analyze a query to identify multiple instances of the same table. Instance numbering for the multiple table instances can then be performed using the query structure such that equivalent queries will likely get the same instance number assignments to improve materialized view recommendations for queries.

Abstract: A technique for refreshing materialized views in a database is disclosed. The detail table is partitioned, and changes made to the detail table are tracked with information stored, for example. Only sections in the materialized view which correspond to the partitions which include modifications made to the detail table are refreshed, thus avoiding the need of a complete refresh to overcome staleness.