Abstract: A method of satisfying a database query includes evaluating certain joins on a per-segment basis. An expression tree is produced for the query, and the expression tree is evaluated to identify joins whose operands are two instances of the same relation and whose join predicate conjunctively includes an equality comparison between two instances of the same column. When such a join is identified, it may be evaluated by segmenting the operand relation according to the columns that are compared for equality in the predicate. The join is then evaluated by performing the join operation separately on each segment. Segments may be spooled separately, thereby exploiting the efficiencies obtained by spooling even where the entire relation is too large to fit in the spool. Execution iterators are provided for spooling successive segments and for applying the join to the spooled segment.

Abstract: A system and methods allowing for the transparent updates of views in database environments is provided. In operation, the partitioned view may be modified, deleted, or replaced using a portioning function. A partitioning function operates on data in the database environment to provide updates of partitioned views. The partitioning function is generated for each partitioned view. The partitioning function is generated by loading the partitioning constraint expression on the partitioning column for each child table of the partitioned view. The tables are remapped such that a view column is superimposed on the partitioning column. The resulting remapped table is stored in an array of expressions that are then processed to produce the partitioning function. The partition-id of each table in the partitioned view is set based on their order of appearance in the initial view definition. Further, the present invention contemplates partitioned column updates and non-partitioned column updates.

Abstract: Validation of large numbers of alternative execution plans for a database query, either an exhaustive enumeration of the complete space of alternatives, or else an unbiased random sample, is performed by efficiently constructing execution trees from a data structure having groups alternative operators that are ranked in a directory. Each global rank of a plan identifies that plan uniquely among all the alternative plans. The operators are unranked from the directory according to a specification that characterizes the desired plans.

Abstract: A query formulates choices of multiple equivalent forms. A choice is represented by a CHOOSE operator having multiple arguments representing the equivalent forms. A lookup table is generated to include a group for each node other than CHOOSE arguments. For CHOOSE arguments, the generated table includes a single equivalence group having all choose arguments as members. The enumeration algorithm of the optimizer is applied to generate additional members and/or groups, whereby for each group, every member thereof is an equivalent. A cost value is assigned to each member of each group and a member of each group is selected as a lowest cost value member. The lowest cost value members of the groups define an optimized tree and optimization of the query.

Abstract: A query optimizer determines the applicability of materialized views to a query. View utilization alternatives are generated in the exploration stage of optimization, so that interaction with other transformations in complex queries is taken into account. A final decision on whether to use a materialized view is based on estimated cost. The optimizer generates a table of alternatives, which compactly encodes the various possibilities for each sub-expression of the query. Optimal-cost operator trees are extracted from this table. Materialized views are detected and substituted during exploration of the various possibilities and added to the table of alternatives. Materialized views and the alternatives are selected for use in a query execution plan based on cost. When two operator trees are not identical, a residual operator can be used if one operator tree subsumes the other operator tree. The residual expression can contain operators such as filters, group by and join.

Abstract: SQL subqueries are converted into equivalent expressions rooted by a special relational operator. The special relational operator assumes properties based on the type of the expression containing the subquery. The context of the subquery is also factored into the special relational operation. The relational operator itself is optimized, when possible, into a standard join operation. The conversion process maintains a list of parameter dependencies within the query and the relational operator utilizes this list at execution time to decrease the amount of processing required to produce the query output.

Abstract: An auto-parameterization process transforms a database query into a parameterized basic query form by replacing any constant values in the query with parameters. The auto-parameterization process attempts to generate a safe execution plan from the basic query form if there is currently no such plan available. A safe execution plan is defined as an execution plan that is optimal over a range of values for the parameters. If a safe execution plan can be generated, it is passed for execution, along with the constant values that were present in the query. If a safe execution plan cannot be generated, the auto-parameterization process passes a specific execution plan for execution. The safe execution plan is cached either at the time it is created or at the time it is executed. The cache is searched each time a parameterized basic query plan is generated by the auto-parameterization process.

Abstract: An integrated circuit arrangement for providing operating voltages for a flash EEPROM memory array, which integrated circuit arrangement utilizes a plurality of charge pumps in a staggered output arrangement to generate a high voltage output while generating lower amounts of current from each individual charge pump so that the provision of the necessary current is integrated over the entire period of the voltage output. Unique circuitry is provided for regulating the value of the output voltage produced by the arrangement in response to variations in the output voltage produced.

Abstract: An integrated circuit charge pump circuit including a plurality of stages, each stage including a first N type field effect switching transistor device having source and drain terminals connected in series with the source and drain terminals of all other stages, a second N type field effect control transistor device having drain and source terminals connecting the drain terminal and the gate terminal of the first switching transistor device, and a storage capacitor joined to the source terminal of the first device; a source of voltage to be pumped is connected to the drain terminal of the first device of the first stage.

Abstract: An integrated circuit charge pump circuit including a plurality of stages, each stage including a first N type field effect switching transistor device having source and drain terminals connected in series with the source and drain terminals of all other stages, a second N type field effect control transistor device having drain and source terminals connecting the drain terminal and the gate terminal of the first switching transistor device, and a storage capacitor joined to the source terminal of the first device; a source of voltage to be pumped is connected to the drain terminal of the first device of the first stage.

Abstract: An integrated circuit charge pump circuit including a plurality of stages, each stage including a first N type field effect switching transistor device having source and drain terminals connected in series with the source and drain terminals of all other stages, a second N type field effect control transistor device having drain and source terminals connecting the drain terminal and the gate terminal of the first switching transistor device, and a storage capacitor joined to the source terminal of the first device; a source of voltage to be pumped is connected to the drain terminal of the first device of the first stage.

Abstract: An integrated circuit arrangement for providing erase voltages to a flash EEPROM memory array including one charge pump for generating a first high voltage with substantial current which may be used for application to the source terminals of flash EEPROM memory cells during erase and to the gate terminals of flash EEPROM memory cells during programming, and another charge pump for generating a second lower voltage which may be used for application to the drain terminals of flash EEPROM memory cells during programming.