Patent application number | Description | Published |
20090083238 | STOP-AND-RESTART STYLE EXECUTION FOR LONG RUNNING DECISION SUPPORT QUERIES - Stop-and-restart query execution that partially leverages the work already performed during the initial execution of the query to reduce the execution time during a restart. The technique selectively saves information from a previous execution of the query so that the overhead associated with restarting the query execution can be bounded. Despite saving only limited information, the disclosed technique substantially reduces the running time of the restarted query. The stop-and-restart query execution technique is constrained to save and reuse only a bounded number of records (intermediate records or output records) thereby releasing all other resources, rather than some of the resources. The technique chooses a subset of the records to save that were found during normal execution and then skipping the corresponding records when performing a scan during restart to prevent the duplication of execution. A skip-scan operator is employed to facilitate the disclosed restart technique. | 03-26-2009 |
20090094191 | EXPLOITING EXECUTION FEEDBACK FOR OPTIMIZING CHOICE OF ACCESS METHODS - A proactive monitoring mechanism for correcting the choice of access methods (available query plans) for a given query, based on execution feedback from the same query. The mechanism exploits bypassing predicate short-circuiting inside the database server's predicate evaluation module to obtain expression cardinalities. The mechanism can also modify a plan to obtain expression cardinalities. These techniques are used judiciously by the query optimizer and/or a database administrator (DBA) so that the execution overheads are within acceptable limits. | 04-09-2009 |
20090254522 | DETECTING ESTIMATION ERRORS IN DICTINCT PAGE COUNTS - A database server may be configured to compute distinct page counts of pages accessed to execute operands of respective queries. The queries may be executed against a table comprised of the pages and having an index managed by the database server. The distinct page counts may be obtained by counting, as a part of the executing of the queries, distinct pages accessed during the execution of the queries. | 10-08-2009 |
20100235347 | TECHNIQUES FOR EXACT CARDINALITY QUERY OPTIMIZATION - An exact cardinality query optimization system and method for optimizing a query having a plurality of expressions to obtain a cardinality-optimal query execution plan for the query. Embodiments of the system and method use various techniques to shorten the time necessary to obtain the cardinality-optimal query execution plan, which contains the query execution plan when all cardinalities are exact. Embodiments of the system and method include a covering queries technique that leverages query execution feedback to obtain an unordered subset of relevant expressions for the query, an early termination technique that bounds the cardinality to determine whether the processing can be terminate before each of the expressions are executed, and an expressions ordering technique that finds an ordering of expressions that yields the greatest reduction in time to obtain the cardinality-optimal query execution plan. | 09-16-2010 |
20100250518 | FLEXIBLE QUERY HINTS IN A RELATIONAL DATABASE - A flexible query hints system and method for discovering and expressing query hints in a database management system. Embodiments of the flexible query hints system and method include a power hints (Phints) language that enables the specification of constraints to influence a query optimizer. Phints expressions are defined as tree patterns annotated with constraints. Embodiments of the flexible query hints system and method also include techniques to incorporate the power hints language expressions into an extended query optimizer. Theses techniques include computing a directed acyclic graph for Phints expression, deriving candidate matches using the Phints expression and the graph, computing candidate matches, and extracting a revised execution plan having a lowest cost and satisfying constraints of the Phints expression. Embodiments of the flexible query hints system and method include a flexible query hint user interface that allow users to interactively adjust query hints. | 09-30-2010 |
20110295833 | Framework for Testing Query Transformation Rules - Described is a test framework for testing transformation rules of query optimizers. Rule patterns obtained as tree structures from a query optimizer are used to generate queries that are used to test the rule optimizer's transformation rules. The test framework tracks which rules are exercised for each query, and also determines the correctness of the transformation rule by comparing the results of the query processing with the rule and without the rule (by turning off the rule). The test framework creates a composite pattern corresponding to two or more rules, such as to test rules in a set (e.g., as pairs). Also described is the efficient execution of a test suite for correctness testing, in which queries of the test suite are selected based upon cost information. | 12-01-2011 |
20110313999 | SLICING RELATIONAL QUERIES USING SPOOL OPERATORS - A relational database server may concurrently execute many relational queries, but a complex relational query may cause performance delays in the fulfillment of other relational queries. Instead, the relational database server may generate a query plan for the relational query, and may endeavor to partition the relational query between a spool operator and a scan operator into two or more query slices, where each query slice may be executed within a query slice threshold. Many alternative candidate query plans may be considered, such as inserting spool and scan operators after various operators and parameterizing operators in order to partition the records of a relation into two or more ranges based on an attribute of the relation. A large search space of candidate query plans may be reviewed in order to select a query plan that respects the query slice threshold while efficiently executing the logic of the relational query. | 12-22-2011 |
20120150841 | AUDITING QUERIES USING QUERY DIFFERENTIALS - Methods and systems for auditing queries using query differentials are disclosed. A method includes identifying a set of queries, determining if results of each query of the set of queries are different from results of respective differentials of each query of the set of queries, and based on the determining, making a characterization of each query of the set of queries as one of safe and unsafe. Access is provided to the characterization of each query of the set of queries. | 06-14-2012 |
20120150877 | EFFICIENT DATABASE COMPRESSION - A method for compressing data. The method includes accessing, within an electronic system, a database relation comprising a plurality of attributes and determining a sort order of the plurality of attributes of the database relation. The method further includes determining an order of a plurality of compression operators operable to compress the database relation and compressing the database relation to produce a compressed database based on the sort order and the order of the plurality compression operators. | 06-14-2012 |
20130132352 | EFFICIENT FINE-GRAINED AUDITING FOR COMPLEX DATABASE QUERIES - The present application provides for techniques for implementing data auditing embodiments that determine whether a query into a database is or has referenced forbidden data within the database. Various techniques are given for efficiently finding all tuples in a database referenced by a given query. A set of sensitive data is determined within a database and the set of sensitive data is employed to define a forbidden view within the database. Data within the database may be annotated to provide efficient identification of data access by query. Incoming queries may be analyzed and modified to propagate annotations for analyzing what data is or was accessed. | 05-23-2013 |
20140164758 | SECURE CLOUD DATABASE PLATFORM - A cloud computing service to securely process queries on a database. A security device and method of operation are also disclosed. The security device may be provisioned with a private key of a subscriber to the cloud service and may have processing hardware that uses that key, sequestering the key and encryption processing in hardware that others, including operating personnel of the cloud service, cannot readily access. Processing within the security device may decrypt queries received from the subscriber and may encrypt responses for communication over a public network. The device may perform functions on clear text, thereby limiting the amount of clear text data processed on the cloud platform, while limiting bandwidth consumed in communicating with the subscriber. Such processing may include formatting data, including arguments in a query, in a security protocol used by the cloud platform. | 06-12-2014 |
20140281511 | SECURE DATA PROCESSING ON SENSITIVE DATA USING TRUSTED HARDWARE - The subject disclosure is directed towards using trusted hardware to achieve secure data processing over a network. For a given set of data store operations, some operations are directed to sensitive data (e.g., encrypted data fields). These operations are compiled into a set of expressions invoking trusted hardware code configured to evaluate these expressions using corresponding data centric primitive programs. Because the trusted hardware is configured to maintain key data for encrypting/decrypting the sensitive data, the sensitive data is not accessible by an untrusted component while the sensitive data is decrypted. | 09-18-2014 |
20140281512 | SECURE QUERY PROCESSING OVER ENCRYPTED DATA - The subject disclosure is directed towards secure query processing over encrypted database records without disclosing information to an adversary except for permitted information. In order to adapting semantic security to a database encryption scheme, a security model for all query processing is specified by a client and used to determine which information is permitted to be disclosed and which information is not permitted. Based upon the security model, a trusted, secure query processor transforms each query and an encrypted database into secure query results. Even though the adversary can view the secure query results during communication to the client, the adversary cannot determine any reliable information regarding the secure query results or the encrypted database. | 09-18-2014 |