Abstract: Under a type of query transformation referred to herein as join factorization, the branches of an UNION/UNION ALL query that join a common table are combined to reduce accesses to the common table. The transformation can be expressed as (T1 join T2) union all (T1 join T3)=T1 join (T2 union all T3), where T1, T2 and T3 are three tables. A given query may be rewritten in many alternate ways using join factorization. Evaluating each alternative can be expensive. Therefore, the alternatives are generated and evaluated in a way that minimizes the cost of evaluating the alternatives.

Abstract: Join predicate push down transformations push down a join predicate of an outer query into a view. Among the types of views for which join predicate push down is performed are a view with a GROUP BY or DISTINCT operator, an anti-joined or semi-joined view, and a view that contains one or more nested views. During optimization, join predicate push down may be used to generate many transformed queries for comparison. The number of query transformations performed for comparison is managed.

Abstract: Under a type of query transformation referred to herein as join factorization, the branches of an UNION/UNION ALL query that join a common table are combined to reduce accesses to the common table. The transformation can be expressed as (T1 join T2) union all (T1 join T3)=T1 join (T2 union all T3), where T1, T2 and T3 are three tables. A given query may be rewritten in many alternate ways using join factorization. Evaluating each alternative can be expensive. Therefore, the alternatives are generated and evaluated in a way that minimizes the cost of evaluating the alternatives.

Abstract: Unnesting using anti-join of NOT IN/ALL subquery uses null-aware anti-join operation, resulting in a rewritten query that, when computed, produces results consistent with the NULL semantics of NOT IN/ALL subquery.

Abstract: During query optimization, when a particular type of transformation is considered, the effect of performing one or more subsequent kinds of transformations is also considered in conjunction with the first. When applying a transformation, which forecloses applying another, both are considered independently.

Abstract: Techniques for reusing optimized query blocks in query processing are provided. The techniques include checking a data structure to determine whether a previously-generated query block information record corresponding to an already-processed first inner query block exists in the data structure, where the already-processed first inner query block corresponds to the first inner query block in a first state in an already-processed form. If the previously-generated query block information record exists in the data structure, then query block information is established for the first inner query block in the first state based on the previously-generated query block information record. Then a cost is determined for a semantically equivalent query that includes the first inner query block in the first state based on the query block information for the first inner query block in the first state.

Abstract: Techniques are provided for determining query cost for a query that include an outer query and at least a first subquery. The techniques include determining a filtering factor for the first subquery based on a first cardinality and a second cardinality. The first cardinality is determined based on a first set of query blocks in the query. The second cardinality is determined based on a second set of query blocks. The first set of query blocks includes the outer query and zero or more subqueries from the query and does not include the first subquery. The second set of query blocks includes all the query blocks in the first set of query blocks and, in addition, the first subquery. The techniques also include determining a cost for the query based, at least, on the filtering factor for the first subquery.

Abstract: The present invention provides methods and compositions for the treatment, prevention, or reduction of persistent infections, such as chronic infections, latent infections, and slow infections and cancer. The methods and compositions of the invention are also useful for the alleviation of one or more symptoms associated with such infections and cancer.

Abstract: Techniques are provided for delaying evaluation of expensive expressions in a query. Expensive expressions in the query are established by cost information or by looking up a list of known expensive expressions for a match. After an execution plan is determined by using the early evaluation technique, one or more equivalent execution plans is established. The one or more equivalent execution plans may include both a type of execution plans that delay evaluation of expensive expressions and a type of execution plans that do not. In addition, the one or more equivalent execution plans may include both parallelized and non-parallelized alternatives to the execution plan identified by the early evaluation technique. Finally, based on a set of criteria, which may include comparing cost information among all the equivalent execution plans generated thus far, the best execution plan is chosen for the query.

Abstract: Various techniques are described for processing database commands that include MINUS and/or INTERSECT operators. According to one technique, the database server executes the MINUS/INTERSECT in a specialized rowsource in parallel. In one approach, the specialized rowsource implements a sort merge-join like solution, where: a DISTINCT SORT is performed on each input, a left and right pointer is maintained on the respective input streams of tuples, the left or right pointer is incremented based on whether there is a match between the tuples pointed-to by the pointers, and the tuple of the left side is returned (or not returned) based on whether there is a match. Techniques are described for generating multiple query plans for executing a query, where each of the query plans includes a plan portion for executing, in parallel, the operation associated with a MINUS/INTERSECT operator. Cost estimates are generated for the query plans.

Abstract: Various techniques are described for processing database commands that include MINUS and/or INTERSECT operators. The queries containing the MINUS and/or INTERSECT operators are transformed to create a plurality of transformed queries. Each of the transformed queries produces the same result as the original query, but does not include the MINUS and/or INTERSECT operator. To achieve the same result set as the original query, the transformed queries employ equijoins, antijoins, and/or semijoins, and duplicate elimination operations. Costs are estimated for each of the various transformed queries. Based on the cost estimates, one of the transformed queries is selected as the query that is to be executed to perform the operations specified in the original query.

Abstract: Statements having non-commutative connection conditions are optimized by replacing the non-commutative connection conditions with equivalent expressions that allow for consideration of additional connection orders that would otherwise violate the ordering rules of the non-commutative connection condition. Elements on the right-hand side of a non-commutative connection condition are converted into distinct results elements, thereby allowing the elements to be used on the left-hand side of a commutative connection operator, while preserving accuracy of the statement results set. This increased set of connection orders is evaluated and the execution plan for the optimal connection order is selected.

Abstract: Iterative, linear, and exhaustive candidate selection techniques are described. In the techniques described herein, a set of semantically equivalent queries (also called a set of candidate queries) is determined for an incoming query based on a particular candidate selection technique. A choice is then made among the candidate queries, usually based on a cost measure, as to which query to execute or store for later execution. In one embodiment, there are multiple, available candidate selection techniques and before the set of candidate queries is determined, a choice of candidate selection techniques is made from among the available candidate selection techniques. The choice of candidate selection techniques may be made based on a configuration file or user input or based on some aspect of the query, the user, or the database on which the query will run.

Abstract: Techniques for reusing optimized query blocks in query processing are provided. The techniques include checking a data structure to determine whether a previously-generated query block information record corresponding to an already-processed first inner query block exists in the data structure, where the already-processed first inner query block corresponds to the first inner query block in a first state in an already-processed form. If the previously-generated query block information record exists in the data structure, then query block information is established for the first inner query block in the first state based on the previously-generated query block information record. Then a cost is determined for a semantically equivalent query that includes the first inner query block in the first state based on the query block information for the first inner query block in the first state.

Abstract: Techniques are provided for determining query cost for a query that include an outer query and at least a first subquery. The techniques include determining a filtering factor for the first subquery based on a first cardinality and a second cardinality. The first cardinality is determined based on a first set of query blocks in the query. The second cardinality is determined based on a second set of query blocks. The first set of query blocks includes the outer query and zero or more subqueries from the query and does not include the first subquery. The second set of query blocks includes all the query blocks in the first set of query blocks and, in addition, the first subquery. The techniques also include determining a cost for the query based, at least, on the filtering factor for the first subquery.

Abstract: Techniques are provided for processing a query including determining a first cost based on the original query; if the query has a subquery, generating a second query with the subquery unnested; determining a second cost based on the second query; determining whether the second query includes a mergeable view; and if the second query includes a mergeable view, then generating a third query with the view merged; determining a third cost based on the third query; and choosing an output query from among the set of semantically equivalent queries based on costs associated with the semantically equivalent queries, where the set of semantically equivalent queries includes two or more of the original query, the second query, and the third query.

Abstract: This invention provides methods of inducing an antiviral response in an individual comprising administering to the individual an effective amount of a LT-B blocking agent and a pharmaceutically acceptable carrier. In particular this invention provides methods for treating viral-induced systemic shock and respiratory distress.

Abstract: This invention provides methods of inducing an antiviral response in an individual comprising administering to the individual an effective amount of a LT-B blocking agent and a pharmaceutically acceptable carrier. In particular this invention provides methods for treating viral-induced systemic shock and respiratory distress.

Abstract: An information management system for managing the concurrent performance of multiple works-in-progress while providing atomicity, consistency, isolation, and durability among transactions involved in the works-in-progress. The information management system includes a database for persistently storing a set of data objects and a set of data changes targeted for the data objects. The information management system includes a library that provides a set of methods that enable an activity to persistently store the data changes in the database while maintaining a work-in-progress such that the data changes are concealed from a global view of the database until the work-in-progress is complete.