Abstract: According to one embodiment of the present invention, a method for processing a query in a column database is provided. The method for analyzing test results may include a computer, associating a first set of metadata values with a set of records in a table, wherein each record has an associated state indicated by a metadata value. The method may further include the computer receiving a query to return one or more records of the set of records. The method may further include the computer determining that one or more records in the set of records satisfies the query. The method may further include the computer determining whether at least a first record in the one or more records that satisfies the query is in a returnable state based, at least in part, on the metadata value.

Abstract: According to one embodiment of the present invention, a method for processing a query in a column database is provided. The method for analyzing test results may include a computer, associating a first set of metadata values with a set of records in a table, wherein each record has an associated state indicated by a metadata value. The method may further include the computer receiving a query to return one or more records of the set of records. The method may further include the computer determining that one or more records in the set of records satisfies the query. The method may further include the computer determining whether at least a first record in the one or more records that satisfies the query is in a returnable state based, at least in part, on the metadata value.

Abstract: A first request may be received to update a first set of values. The first set of values may be stored at a first location within a first data page of a database. The first location may be read-only. In response to the receiving of the first request, a first set of records may be inserted into a second data page. The first set of records may include the update of the first set of values. In response to the inserting, a forward pointer may be stored in the first data page that points to the first set of records on the second data page. One or more committed values may be identified on the second data page. In response to the identifying, the one or more committed values may be merged from the second data page to a third data page.

Abstract: Embodiments of the present invention provide systems and methods for data management. Synopsis tables have been found to be more effective for maintaining a high level of system performance while answering analytical queries. Synopsis tables, which contain MAX, MIN, and Bloom filter columns, may be modified by dropping ineffective data content within these columns and regenerating dropped data when beneficial. By automatically modifying data, database queries may be optimized.

Abstract: Merging adjacent rows of a synopsis table so as to increase the effectiveness of the synopsis table regarding data skipping. Adjacent rows for merging are identified based on statistics regarding: (i) queries of the database; (ii) effectiveness of the synopsis table for data skipping; and (iii) usage of predicates in queries of the database. Once merged, the synopsis table is smaller, and more effective with respect to data skipping, while fewer computing resources (administrative, maintenance, memory, clock cycles, storage space, etc.) are needed to process the database queries.

Abstract: Merging adjacent rows of a synopsis table so as to increase the effectiveness of the synopsis table regarding data skipping. Adjacent rows for merging are identified based on statistics regarding: (i) queries of the database; (ii) effectiveness of the synopsis table for data skipping; and (iii) usage of predicates in queries of the database. Once merged, the synopsis table is smaller, and more effective with respect to data skipping, while fewer computing resources (administrative, maintenance, memory, clock cycles, storage space, etc.) are needed to process the database queries.

Abstract: A method for optimizing query compilation by tuning memory across a database cluster is provided. The method may include receiving, by a global memory tuner, memory configuration information from a plurality of nodes within the database cluster. The method may also include determining a node within the plurality of nodes having a least available memory value relative to a remainder of nodes within the plurality of nodes based on the received memory configuration information. The method may then include calculating a globally tuned memory value based on a memory value associated with the determined node. The method may further include determining a memory distribution based on the calculated globally tuned memory value. The method may also include sending the determined memory distribution to the plurality of nodes.

Abstract: A method for optimizing query compilation by tuning memory across a database cluster is provided. The method may include receiving, by a global memory tuner, memory configuration information from a plurality of nodes within the database cluster. The method may also include determining a node within the plurality of nodes having a least available memory value relative to a remainder of nodes within the plurality of nodes based on the received memory configuration information. The method may then include calculating a globally tuned memory value based on a memory value associated with the determined node. The method may further include determining a memory distribution based on the calculated globally tuned memory value. The method may also include sending the determined memory distribution to the plurality of nodes.

Abstract: A current minimum memory requirement for each memory consumer of one or more memory consumers of a primary database system is received. A current memory allocation for a standby database system is received. A set of benefit-to-cost metrics is received. A benefit-to-cost metric is a measure of whether each memory consumer would benefit or would not benefit from additional memory. The set of benefit-to-cost metrics is applied to the standby database system to define an upper bound memory allocation of the standby database system to function in the event of a failover from the primary database system. A scaling factor is determined. In response to receiving an indication of a failover of the primary database system to the standby database system, a ramp up of the standby database system is monitored. The ramp up of the standby database system uses the set of benefit-to-cost metrics and the determined scaling factor.

Abstract: A method includes scanning multiple incoming database transaction requests. Each transaction includes one or more operations. Operations are clustered into a set of combined operations based on type of operation constraints. Log records are prepared and written for re-performing operations upon system failures, and for undoing operations upon an operation or a transaction failing to be processed fully. Each set of combined operations are performed within a thread. Each update operation is marked for a transaction within which the update operation belongs. Recoverable update operations belonging to a plurality of transactions are performed within a single logical thread of execution.

Abstract: A current minimum memory requirement for each memory consumer of one or more memory consumers of a primary database system is received. A current memory allocation for a standby database system is received. A set of benefit-to-cost metrics is received. A benefit-to-cost metric is a measure of whether each memory consumer would benefit or would not benefit from additional memory. The set of benefit-to-cost metrics is applied to the standby database system to define an upper bound memory allocation of the standby database system to function in the event of a failover from the primary database system. A scaling factor is determined. In response to receiving an indication of a failover of the primary database system to the standby database system, a ramp up of the standby database system is monitored. The ramp up of the standby database system uses the set of benefit-to-cost metrics and the determined scaling factor.

Abstract: Embodiments relate to database systems. An aspect includes deferring row insert operations until occurrence of a triggering event. One method includes receiving a row insert for a tuple into a column group store table, where the tuple includes one or more tuplets and each of the tuplets corresponds to a column group in the column group store table. The method also includes copying at least one of the tuplets into an insert buffer that is specific to one of the column groups in the column group store table. The method also includes deferring the row insert into the column group store table until an occurrence of one or more triggering events. The method also includes flushing the row insert into storage associated with the column group store table, in response to the occurrence of the one or more triggering events.

Abstract: An indication to load data into a database table is received. A determination is made whether an existing set of frequency distribution statistics is available. In response to determining that an existing set of frequency distribution statistics is available, the data is loaded into the database table using the existing set of frequency distribution statistics.

Abstract: An indication to load data into a database table is received. A determination is made whether an existing set of frequency distribution statistics is available. In response to determining that an existing set of frequency distribution statistics is available, the data is loaded into the database table using the existing set of frequency distribution statistics.

Abstract: In updating a synopsis table of a database system, a database management unit performs a transaction to insert row(s) in a section of the base table and determines whether a synopsis entry for the section is stored in the memory. If stored in the memory, the in-memory synopsis entry is retrieved and metadata values in the in-memory synopsis entry are updated with data from the row(s) to be inserted. If not stored in the memory, the in-memory synopsis entry is generated and the metadata values in the in-memory synopsis entry are updated with data from the row(s). The insert transaction is then committed. Synopsis entry on-disk updates are thus avoided, significantly reducing the cost of updating the synopsis entries from the insert transaction. This yields enhanced performance especially for inserts of a small number of rows, while the benefits of synopsis entries are still available.

Abstract: A computer-implemented method includes assigning a threshold value to a memory consumer and assigning a bias value to the threshold value. The ability to free memory of the consumer by the consumer is monitored. In response to a determination to reclaim the memory, the consumer is directed to reclaim the memory. The threshold value is transformed responsive to whether the reclaiming exhibits at least one of time-out or completion of reclaim after a predetermined time. Per memory consumer control values are updated and the memory is logically partitioned according to a defined ratio into at least a first portion and a second portion. Subsequent to directing the consumer to reclaim the memory, the memory is reclaimed from the second portion and, subsequently, the second portion is replenished from the first portion in a manner that maintains the defined ratio. A corresponding computer system and computer program product are also disclosed.

Abstract: A first request may be received to update a first set of values. The first set of values may be stored at a first location within a first data page of a database. The first location may be read-only. In response to the receiving of the first request, a first set of records may be inserted into a second data page. The first set of records may include the update of the first set of values. In response to the inserting, a forward pointer may be stored in the first data page that points to the first set of records on the second data page. One or more committed values may be identified on the second data page. In response to the identifying, the one or more committed values may be merged from the second data page to a third data page.

Abstract: A first request may be received to update a first set of values. The first set of values may be stored at a first location within a first data page of a database. The first location may be read-only. In response to the receiving of the first request, a first set of records may be inserted into a second data page. The first set of records may include the update of the first set of values. In response to the inserting, a forward pointer may be stored in the first data page that points to the first set of records on the second data page. One or more committed values may be identified on the second data page. In response to the identifying, the one or more committed values may be merged from the second data page to a third data page.

Abstract: A first request may be received to update a first set of values. The first set of values may be stored at a first location within a first data page of a database. The first location may be read-only. In response to the receiving of the first request, a first set of records may be inserted into a second data page. The first set of records may include the update of the first set of values. In response to the inserting, a forward pointer may be stored in the first data page that points to the first set of records on the second data page. One or more committed values may be identified on the second data page. In response to the identifying, the one or more committed values may be merged from the second data page to a third data page.

Abstract: A first request may be received to update a first set of values. The first set of values may be stored at a first location within a first data page of a database. The first location may be read-only. In response to the receiving of the first request, a first set of records may be inserted into a second data page. The first set of records may include the update of the first set of values. In response to the inserting, a forward pointer may be stored in the first data page that points to the first set of records on the second data page. One or more committed values may be identified on the second data page. In response to the identifying, the one or more committed values may be merged from the second data page to a third data page.